MOSP - Macao Scientific Publishers

Research Article

Detection and identification of groundwater bacteria in Sebha City, Libya

Salem, A. Mahfouz F. M. Shaieb and A.E.K Elzen

Abstract: Drinking water systems supplied by untreated groundwater were examined to determine whether coliform or heterotrophic plate count bacteria are capable of growing. Filterable bacteria were present in 42% of the 46 groundwater sources examined by using nonselective media (R2A and full strength m-HPC agars). Pseudomonads were the most frequently identified group of filterable bacteria detected. Flavobacterium, Alcaligenes, Acinetobacter and Achromobacter isolates were also identified. Total coliforms were recovered only from six samples taken from wells near the wastewater lagoon, following filtration through 0.45-µm-pore-size membrane filters by using selective M- Endo LES agar or mT7 agar. In addition, none of the isolates identified from nonselective media were coliforms. Similarly, neither total coliforms nor specifically Escherichia coli were detected in these filtrates when Colilert P/A medium was used[...] Read More.

Keywords: ground water, contamination, Flavobacterium, Alcaligenes, Acinetobacter, Achromobacterand E. coli

2012, 11(1), 1-6;

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Research Article

Purification and properties of a non-stereospecific dehalogenase enzyme E (DehE) from Methylobacterium sp. HJ1

Ng Hong Jing, Fatin Hanani Sulaiman, Roswanira Ab. Wahab, Rolando V. Pakinging Jr. , Noor Aini Abdul Rashid and Fahrul Huyop*

Abstract: The bacterial isolate HJ1, which was identified as a Methylobacterium sp., grew on 2, 2-dichloropropionic acid as the sole carbon source and produced a 2-haloalkanoic acid hydrolytic dehalogenase. This non-stereospecific dehalogenase E (DehE) catalysed the hydrolytic dechlorination of 2, 2-dichloropropionic acid and D, L-2-chloropropionic acid to produce pyruvate and lactate, respectively. The enzyme was purified to homogeneity and characterized. The molecular weight was 36 kDa by SDS-polyacrylamide gel electrophoresis and 72 kDa by gel filtration, suggesting that the enzyme is a protein dimer. The purified enzyme was only inhibited by HgSO4 and was non-stereospecific to haloalkanoic acids. The Km value for the hydrolysis of 2, 2- dichloropropionic acid was 0.25 mM. The enzyme removes chloride present on the -position, but not on the -position, of a number 2–carbon alkanoic acids.[...] Read More.

Keywords: haloalkanoic acid, dichloropropionate, 2, 2-dichloropropionic acid.

2012, 11(1), 1-6;

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Research Article

Immune response and protection of free range chickens vaccinated orally with feeding of newcastle disease vaccine-coated cassava granules

Echeonwu G. O. N*, Iroegbu C. U, Echeonwu B. C, Ngene A, Nwosuh C. I, Joannis T. M and Ndako J.

Abstract: Cassava granules coated with Newcastle disease virus (NDV) strain V4-UPM was used to vaccinate free-range chickens in their natural habitat. Immune response, vaccine virus excretion and the efficacy of the food vaccine were assessed by standard methods. Results show that out of 218 chickens given initial food vaccine in the four locations, 138 (63.3%) produced detectable HI antibody while 202 (92.7%) had titres < 3.0. However, only 16 (7.3%) attained log2 3.0 with GMT of 3.2. This was made up of Nchara- Akanu 7(12.7%), Vandekya 0(0.0%), Fadan Karshi 1(1.7%), and Turu 8(15.1%) with GMTs of 3.3, 2.9, 3.0, and 3.6 in that order. Following the administration of a booster dose of vaccine on 194 birds in the same flocks, 170(87.6%) sero-converted with 118(60.8%) attaining log2 3.0 and GMT of 9.7. Chickens attaining HI titres up to log2 3.0 from the locations were as follows, Nchara-Akanu 26(51.0%), Vandekya 22 (51.2%), Fadan Karshi 28(53.8%), and Turu 33(68.8%) with GMTs of 12.8, 7.5, 7.0, and 12.6 respectively. Vaccinated birds excreted infective vaccine virus. Out of 55 buyback chickens challenged, 15(27.3%) died while 40(72.7%) survived. Twenty two (22) out of 24 (91.7%) unvaccinated birds challenged died and only 2(8.3%) survived. It is therefore concluded that cassava granules could be good carrier for food-borne ND vaccine delivery to village chickens in Nigeria.[...] Read More.

Keywords: Cassava, V4-UPM virus, village chickens, Newcastle disease.

2012, 11(1), 1-6;

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Research Article

Improvement of the quality and shelf life of concentrated yoghurt (labneh) by the addition of some essential oils

Mutlag Al.Otaibi* and Hassan El.Demerdash

Abstract: Three essential oils, namely thyme, marjoram and sage, were added to concentrated yoghurt (labneh) at concentrations of 0.2, 0.5 and 1.0 parts per million (ppm). Subsequently, the chemical, microbiological and organoleptic properties of freshly prepared labneh and of the labneh stored at 5˚C ± 1 for up to 21 days were determined. Addition of essential oils affected the pH, soluble nitrogen -to-total nitrogen, total volatile fatty acid and acetaldehyde values of the prepared labneh. On the other hand, total solids and fat-to-dry matter values were only slightly affected. Total viable counts, as well as counts of Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus in the treated labneh increased and reached a maximum after 7 days of storage where after it decreased until the end of the storage period. Yeasts and moulds, coliform bacteria and spore-forming bacteria were not detected in the treated labneh. Of the different treated labneh, labneh containing 0.2 ppm thyme, marjoram or sage oils were organoleptically the most acceptable, and it had a good body and texture that was similar to that of the untreated control. From the results of this study, it can be concluded that 0.2 ppm of thyme, marjoram or sage can be used in order to increase the shelf life of labneh for up to 21days.[...] Read More.

Keywords: Labneh, essential oils, shelf life, chemical properties, microbiological properties

2012, 11(1), 1-6;

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Research Article

An improved method for the extraction of nematodes using iodixanol (OptiPrepïƒ”)

Dewang Deng, Allan Zipf, Y. Tilahun, G.C.Sharma, J. Jenkins and K. Lawrence

Abstract: A new nematode extraction technique was established, which is based on an iso-osmotic density- gradient medium (OptiPrepTM). This technique resulted in significantly higher numbers of clean eggs and vermiform nematodes that retain higher viability (48.6%) than samples processed with the sucrose method (28.7%). Nematodes survived exposure to OptiPrepTM for 22 hours without significant mortality whereas all nematodes died in the sucrose medium. OptiPrepTM provided a suitable, non-toxic alternative to the traditional density gradient material for the isolation of nematodes. This technique is convenient and relatively simple, with the added benefit of yielding cleaner samples compared to traditional isolation techniques.[...] Read More.

Keywords: nematode extraction, density gradient, nematology.

2012, 11(1), 1-6;

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Research Article

Carbon nutrition in relation to growth of three Monascus species isolated from decaying date fruits

I. B. Omamor, E. I Eziashiand A. A. Adekunle

2012, 11(1), 1-6;

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Research Article

Antibacterial activity of Asperugo procumbens L. against some human pathogenic bacteria

M. Ahanjan, *, D. C. Mohana and K. A. Raveesha

Abstract: Petroleum ether, chloroform (CHCl3), ethanol (EtOH), methanol (MeOH) and aqueous (H2O) extracts of leaves of Asperugo procumbens L. were evaluated for antibacterial activity against five human pathogenic bacterial strains with the agar-well diffusion method. The methanol extract was highly active against all the test bacteria, followed by the ethanol and aqueous extracts. The chloroform and petroleum ether extracts did not show any antibacterial activity. The minimum inhibitory concentration (MIC) of the methanol extract ranged between 1.56 and 12.5 mg/ml. The results of this study provide support for the use of A. procumbens L. in Iran for traditional medicines.[...] Read More.

Keywords: Asperugo procumbens, antibacterial activity, methanol extract, traditional medicine.

2012, 11(1), 1-6;

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Research Article

Comparison of five serological diagnostic assays for the detection of IgM and IgG antibodies to dengue virus

Shamala Devi Sekaran*, Ew Cheng Lan and Geetha Subramaniam

Abstract: Difficulties in the management of dengue infections include the lack of rapid diagnostic methods and symptoms of dengue are often confused with those of other diseases. Five commercial kits were evaluated for the detection of dengue-specific IgM and IgG antibodies using sera obtained from patients with primary and secondary dengue infections, as well as other febrile illnesses. All kits were compared to the in-house IgM ELISA and HI assays. The rapid test kits took either 30 to 45 min (PanBio Dengue Duo Cassette, Accusens Dengue Virus Rapid Strip Test, and Unitest Dengue IgM and IgG Combo Rapid Test) or between 2 to 4 h (PanBio Dengue Duo Capture ELISA, and Antivirus IgM Detecion Kit 96 [Pentax Corporation]). Most kits were able to detect IgM in more than 90% of the secondary convalescent sera, while IgG detection was generally high (80 to 100%). All five kits showed high specificity when tested against sera from other febrile patients, and have been shown to be extremely useful in the diagnosis of dengue infections.[...] Read More.

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2012, 11(1), 1-6;

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Research Article

Ethanol production from the water hyacinth Eichhornia crassipes by yeast isolated from various hydrospheres

GO. Ogawa Masami, IshidaYukinari Usui and Naoto Urano*

Abstract: Water hyacinth is a promising plant for the production of bioethanol. The water hyacinth was saccharified with diluted sulfuric acid and fermented to ethanol by yeast obtained from different hydrospheres. We found that the best conditions for water hyacinth hydrolysis were 1% (v/v) sulfuric acid at 121oC for 1 h. In the next step, we searched for yeast that could produce ethanol from the water hyacinth hydrolysate. For this, 624 strains were isolated from 28 bodies of water. Strain 484 produced 22.4 ml of ethanol/kg of dried water hyacinth, which suggests that it may be an efficient producer of bioethanol. Through sequence analysis, we identified strain 484 as Candida intermedia.[...] Read More.

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2012, 11(1), 1-6;

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Research Article

Solubilization of inorganic phosphates and plant growth promotion by strains of Pseudomonas fluorescens isolated from acidic soils of Cameroon

FANKEM Henri, NGO NKOT Laurette, DEUBEL Annette, QUINN John, MERBACH Wolfgang, ETOA François-Xavier and NWAGADieudonné*

Abstract: A trial of a screening and selection strategy for phosphate-solubilizing bacteria based on phosphate solubilization ability, and the subsequent effect of these strains on plant growth promotion under in situ conditions was conducted. Of all the bacteria tested, three Pseudomonas fluorescens strains (CB501, CD511 and CE509) were selected. On agar plates, two strains (CB501 and CE509) showed an ability to solubilize the three phosphate types (Ca3 (PO4)2, AlPO 4·H2O or FePO4·2H2O), while strain CD511 showed a halo zone only on an agar plate supplemented with iron phosphate (Fe-P). However, in liquid media, all the strains were able to mobilize significant amounts of phosphorus (P) depending on the phosphate type. Calcium phosphate (Ca-P) solubilization resulted from the combined effects of pH decrease and carboxylic acids synthesis. At pH 4, it was solubilized by most of the organic acids. However, the synthesis of carboxylic acids was the main mechanism involved in the process of aluminium phosphate (Al-P) and Fe-P solubilization. Both were mobilized at pH 4 by citrate, malate, tartrate, and on a much lower level by gluconate and trans-aconitate. Subsequently, a greenhouse trial was conducted using Zea mays, the results of which obtained using 5 parameters including grain yield and P uptake, revealed that strain CB501 was the best plant growth promotor with a global effect of +37%, followed by strain CE509 (+21.2%) and then by strain CD511 (+16.7%). However, the selection of phosphate-solubilizing Pseudomonas strains as possible inoculation tools for phosphate-deficient soils should focus on the integral interpretation of laboratory assays, greenhouse experiments and field trials.[...] Read More.

Keywords: Carboxylic acids, Phosphate solubilization, plant growth, Pseudomonas fluorescens.

2012, 11(1), 1-6;

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Research Article

Statistical optimization of medium components for chromate reduction by halophilic Streptomyces sp. MS-2

Mona E. M. Mabrouk

Advanced Journal of Microbiology Research Vol. 2012

Available online at http://internationalscholarsjournals.org/journal/ajmr

Full Length Research Paper

Statistical optimization of medium components for chromate reduction by halophilic Streptomyces sp. MS-2

Mona E. M. Mabrouk

Botany Department, Faculty of Science, Damanhour, Alexandria University, Egypt. E-mail: mona_mabrouk_eg@hotmail.com.

Accepted 18 March, 2012

Extensive use of hexavalent chromium Cr(VI) in various industrial applications has caused substantial environmental contamination. A marine bacterium, Streptomyces sp. MS-2 showed a high Cr(VI) reduction performance. Streptomyces sp. MS-2 completely reduced 75 mg/l Cr(VI) within 72 h of growth. The effectiveness of the bacterium for reducing Cr(VI) under different conditions was evaluated. Optimum pH and temperature were 7.0 and 37^oC, respectively. Statistical screening of medium components for Cr reduction by Streptomyces sp. MS-2 was carried out by Plackett–Burman design. Peptone, yeast extract, inoculum size, and volume of the medium were shown as significant components influencing Cr(VI) reduction. By applying a verification experiment, Streptomyces sp. MS-2 completely reduced 75 mg of Cr(VI) to Cr(III) within 12 h. This optimization strategy led to a 6-fold increase in the reduction rate. This holds great promise for detoxification of Cr(VI) under a wide range of environmental conditions.

Key words: Streptomyces MS-2; hexavalent chromium; Plackett–Burman design.

2012, 11(1), 1-6;

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Research Article

Microbiological quality of water, associated management practices and risks at source, transport and storage points in a rural community of Lungwena, Malawi

Taulo, S., *, Wetlesen, A., Abrahamsen, R., Mkakosya, R. and Kululanga, G.

Abstract: This study investigated and compared the microbiological quality of source, transported and stored water in Lungwena households. It also examined water management practices at all the investigated points. One hundred and eighty (180) water samples were collected from 6 villages and tested for Escherichia coli, Salmonella, E .coli 0157:H7 and Campylobacter jejuni using standard methods. Water contamination practices were observed in two hundred and eighty seven households. E. coli, Salmonella, E. coli 0157:H7 and C. jejuni were isolated in 54, 24, 6.7 and 2.2% of the samples, respectively. Sampling points revealed a significant difference (p = 0.001) in E. coli concentration. Salmonella concentration between sampling points was not significant (p > 0.05). E. coli concentration was significantly (p = 0.042) higher than that of Salmonella spp. The microbiological quality of water was found to be poor as a result of both poor water management practices and environmental sanitation. There were no significant differences (p > 0.05) in water management practices among the villages.[...] Read More.

Keywords: Pathogens, stored water, transport water, water contamination.

2012, 11(1), 1-6;

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Research Article

Drynaria quercifolia (L.) J.Sm: A potential resource for antibacterial activity

M. Kandhasamy, K. D. Arunachalam* and A. J. Thatheyus

Abstract: Six different organic solvents such as ethanol, methanol, petroleum ether, hexane, benzene and chloroform were used to extract the bioactive compounds from the rhizome of Drynaria quercifolia to screen the antibacterial activity against infectious disease causing bacterial pathogens such as Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella typhi, Salmonella paratyphi A, Salmonella paratyphi B, Salmonella marscence, Staphylococcus aureus and Bacillus subtilis by agar diffusion method. The ethanolic extract of D. quercifolia was more active against 80% of the organisms tested. It was followed by methanolic extract (70%), benzene (50%) and chloroform extract (40%) in inhibiting the growth of the organisms tested. Petroleum ether and hexane extract of D. quercifolia did not show any antibacterial activity against any of the pathogenic bacteria tested. Among the bacteria tested, gram-negative bacteria were more susceptible to the crude extracts compared to gram-positive bacteria. Among gram-positive bacteria, S. aureus was susceptible to ethanolic, methanolic and chloroform extracts whereas B. subtilis was susceptible to methanolic extract of D. quercifolia alone. In the present study ethanolic and methanolic extracts of rhizome of D. quercifolia showed high efficiency of antibacterial activity and gram-negative bacteria were more susceptible to all the extracts tested.[...] Read More.

Keywords:

2012, 11(1), 1-6;

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Research Article

In vitro detection and characterization of bacteriocin-like inhibitory activity of lactic acid bacteria (LAB) isolated from Senegalese local food products

Michel Bakar DIOP, Robin DUBOIS-DAUPHIN, Carine DORTU, Jacqueline DESTAIN, Emmanuel TINE, and Philippe THONART,

Abstract: The prevalence of lactic acid bacteria (LAB) in Senegalese local food products was determined to be 109 CFU/g in millet flour and milk products, and 103 CFU/g in seafood products. These food products are generally preserved by spontaneous fermentation (without addition of starters). Of 220 lactic acid bacteria strains randomly selected from such products, 12 isolates capable of producing bacteriocin-like substances (bac+) were detected. Based on the use of API 50 CH test kits and 16S rDNA sequencing, 11 isolates were characterized as Lactococcus lactis subsp. lactis strains and one as an Enterococcus faecium strain. Nisin- and enterocin B-encoding genes were respectively identified in the bac+ lactococcal strains and the E. faecium strain. Since the bac+ Lc. lactis strains were isolated from different products, it suggests a high potential of growth by these strains in variable ecological environments. Expression of the nisin gene was indicated for one of the lactococcal strains, designated Lc. lactis subsp. lactis CWBI-B1410, which showed the highest in vitro antibacterial activity. An antibacterial preparation prepared from the CWBI-B1410 strain showed many similarities with nisin with regards to its inhibitory effects, heat resistance, protease sensitivity profile, as well as retention time of the antibacterial substances on a C18 column. These results suggest that a nisin-like substance is produced by the CWBI-B1410 strain. This strain has been selected for application as an additional barrier to supplementation with sodium chloride as a means to improve the bacterial quality of fish commodities in Senegal.[...] Read More.

Keywords: Lactococcus lactis, antimicrobial, bacteriocins, Nisin-like substance.

2012, 11(1), 1-6;

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Research Article

Chemical composition, antioxidant and antimicrobial properties of the essential oil of Dacryodes edulis (G. Don) H. J. Lam from Gabon

L. C. Obame, P. Edou, I. H. N. Bassolé*, J. Koudou, H. Agnaniet, F. Eba and A. S. Traore

Abstract: The essential oil obtained by hydrodistillation from the resin of Dacryodes edulis (G. Don) H. J. Lam was simultaneously analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC -MS). Twenty four components were identified in the essential oil and the main components were sabinene (21.8%), terpinene-4-ol (19.8%), -pinene (17.5%) and p-cymene (11.3%), respectively. The antioxidant capacity of the essential oil was examined using an in vitro radical scavenging activity test and -carotene-linoleic acid assays. In the 2.2-Diphenylpicrylhydrazyl (DPPH) test system, the IC50 value of D. edulis oil was 68.5 ± 2.29 µg/ml. In the -carotene-linoleic acid test system, oxidation of linoleic acid was effectively inhibited by D. edulis (70.0%). The oil was less effective than butylated hydroxytoluene (BHT). Furthermore, the essential oil was evaluated for its antimicrobial activity using disc diffusion and microdilution methods. The essential oil showed better activity against bacterial species than against yeast.[...] Read More.

Keywords: Dacryodes edulis, Burseraceae, essential oil, antimicrobial activity; antioxidant activity; gas chromatography-mass spectrometry.

2012, 11(1), 1-6;

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Research Article

In vitro anti-bacterial activity of a novel isoquinoline derivative and its post antibacterial effects on Pseudomonas aeruginosa

Piyush Bihari Lal, Naresh Kumar, Tasleem Arif, T. K. Mandal, K. Akhilesh Verma, G. L. Sharma and Rajesh Dabur*

Abstract: The isoquinolines are of great importance to humanity because of their medicinal value and different structure. There have been many researches on the isoquinolines, but relatively few pure compounds have been investigated for their antibacterial activity. The in vitro activity of a novel synthetic antimicrobial compound 1-(4-choloro-phenyl)-6,7-dimethoxy-2-methyl-1,2,3,4,- tetrahydroisoquinoline was evaluated against Pseudomonas aeruginosa (ATCC27853) using standard methods approved by Clinical and Laboratory Standards Institute. The minimum inhibitory concentration of the compound which inhibited more than 90% growth (MIC90) of P. aeruginosa was found to be ranged from 24.0 to 6.0 g ml-1 in different media. The ET50 (concentration which lyses 50% erythrocytes) of the compound was observed to be 450 g ml-1. It was found that the compound down-regulated the expression of PQS, elastase and pyocyanin, the important virulence factors of P. aeruginosa. Proteomics studies revealed that the compound inhibited/down regulated the expression of PhnA and oprL proteins of P. aeruginosa which are crucial for PQS synthesis and membrane integrity. This type of compounds may provide avenue for the discovery of clinically useful antibacterial drugs.[...] Read More.

Keywords: Isoquinoline, P. aeruginosa, virulent factors, antimicrobial activity, proteomics.

2012, 11(1), 1-6;

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Research Article

Biodegradation of hydrocarbons in untreated produce water using pure fungal cultures

C. C. Okoro

Abstract: Biodegradation studies of hydrocarbons in untreated produce water from an oil production facility in Nigeria were undertaken over a period of time using pure fungal cultures (Penicillium sp. and Aspergillus niger). The rate of reduction in some petroleum hydrocarbon fractions, such as n-alkanes, aromatics, nitrogen, sulfur and oxygen (NSO)-containing compounds and polycyclic aromatic hydrocarbons (PAHs), were monitored by means of gas chromatography and mass spectrometery, using mechanically treated produce water as a reference. Gas chromatographic analysis showed that untreated produce water with an oil and grease content of 1407 mg/l contained various petroleum hydrocarbon fractions, including n- alkanes (608 mg/l), aromatics (13.88 mg/l), NSO compounds (12.68 mg/l) and PAHs (0.833 mg/l). Upon mechanical treatment, the oil and grease content of the produce water was reduced to 44 mg/l, while n-alkanes, aromatics, NSO compounds and PAHs were reduced to 38.4, 2.65, 1.78 and 0.0655 mg/l, respectively.A pure culture of Penicillium sp. reduced the oil and grease content to 72.3 mg/l, comprising of n-alkanes (65.50 mg/l), aromatics (0.98 mg/l), NSO compounds (1.64 mg/l) and PAHs (0.0021 mg/l) after 120 days of exposure. However, A. niger reduced the oil and grease content to 59.1 mg/l, comprising of n-alkanes (56.50 mg/l), aromatics (0.65 mg/l), NSO compounds (0.96 mg/l) and PAHs (0.008 mg/l) after 120 days of exposure. The results indicate that produce water is readily biodegradable and that fungal cultures have the capability to degrade the recalcitrant PAH component of the petroleum hydrocarbon mixture in produce water. Biodegradation rates were, however, slightly more enhanced by using A. niger than Penicillium sp.[...] Read More.

Keywords: Biodegradation, fungal cultures, petroleum hydrocarbons,produce water.

2012, 11(1), 1-6;

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Research Article

In vitro screening of antibacterial activity of aqueous and alcoholic extracts of various Indian plant species against selected pathogens from Enterobacteriaceae

Parekh J and Chanda S*

Abstract: Thirty four medicinal plants, belonging to twenty eight different families, were screened for potential antibacterial activity against six bacterial strains belonging to Enterobacteriaceae, viz. Enterobacter aerogenes ATCC13048, Escherichia coli ATCC25922, Klebsiella pneumoniae NCIM2719, Proteus mirabilis NCIM 2241, Proteus vulgaris NCTC8313, and Salmonella typhimurium ATCC23564. Antibacterial activity of aqueous and alcoholic extracts was tested by the agar disc diffusion and agar well diffusion methods. The ethanol/methanol extracts were more active than aqueous extracts for all the plants studied. The most susceptible bacterium was K. pneumoniae, while the most resistant bacteria were S. typhimurium and E. coli. From the screening experiment, Woodfordia fruticosa Kurz. showed best antibacterial activity. Hence, this plant may be used further to isolate and evaluate the therapeutic antimicrobials.[...] Read More.

Keywords: Medicinal plants, antibacterial activity, aqueous extracts, alcoholic extracts, Enterobacteriaceae.

2012, 11(1), 1-6;

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Research Article

Microbiology of polyethylene-packaged sliced watermelon (Citrullus lanatus) sold by street vendors in Nigeria

E. Nwachukwu*, C. F. Ezeama and B. N. Ezeanya.

Abstract: Ten packaged, freshly sliced watermelon were collected from different street vendors to determine their microbiological quality. Eight different microbial isolates were obtained from the sliced watermelon samples, namely Escherichia coli, Klebsiella aerogenes, Proteus mirabilis, Staphylococcus aureus, Lactobacillus spp., Saccharomyces cerevisiae, Rhizopus stolonifer and Mucor spp. The effects of high density polyethylene (HDP) and low density polyethylene (LDP) packaging bags on the microbiological quality of freshly sliced watermelon, stored at ambient temperature were also determined. After 10 days of storage, the total viable counts increased from 0.6 x 103 cfu/g to 5.3 x 103cfu/g and to 5.5 x 103 cfu/g in the HDP- and LDP-packaged watermelon samples, respectively. The total fungal counts increased from 0.5 x 103cfu/g to 6.7 x 103cfu/g and to 7.2 x 103cfu/g in the HDP- and LDP-packaged watermelon samples, respectively. Proper sanitation practice and use of good quality packaging materials are recommended in order to avoid risks associated with the consumption of sliced food produce.[...] Read More.

Keywords: Watermelon, microbiological quality, packaging materials.

2012, 11(1), 1-6;

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Research Article

Fate of Salmonella typhimurium on rosemary and barley grown in fields treated with contaminated irrigation water

Dhiaf Amel and Bakhrouf Amina

Abstract: Animal wastes in the form of manure frequently contain enteric pathogenic microorganisms and land spreading can lead to pathogen entry into the food chain. Therefore, the aim of the present study was to determine the persistence of Salmonella enterica serovar typhimurium in soil, and on barley and rosemary plants. We observed that Salmonella typhimurium persisted for an extended period of time (203 to 231 days), and could be detected on infected vegetative parts of the rosemary and barley plants even after desiccation. After approximately two months, the colony morphology displayed a mucoid and rugose phenotype. Smooth colony morphology was acquired following incubation in nutrient broth and upon isolation from the digestive tracts of mice that had been challenged orally with stressed S. typhimurium. S. typhimurium was neither isolated from vegetative parts formed after plant contamination, nor from barley seeds and rosemary flowers. Keywords: Salmonella, soil, rosemary, barley, contamination.[...] Read More.

Keywords: Salmonella, soil, rosemary, barley, contamination.

2012, 11(1), 1-6;

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Research Article

Clostridium perfringens type A beta2 toxin in elephant (Elephas maximus indicus) and pygmy hog (Sus salvanius) with haemorrhagic enteritis in Assam, India

Arunava Das, Yahya Mazumder*, Biman K. Dutta, Bibek R. Shome, Komal M. Bujarbaruah and Gauri D. Sharma

Abstract: This paper reported the investigation of haemorrhagic enteritis in female elephant (Elephas maximus indicus) and pygmy hog (Sus salvanius) at the Assam State Zoo, Guwahati, Assam, India. An eight year old female elephant and two and half year old female pygmy hog developed haemorrhagic enteritis of unknown cause maintained at the zoo died within four days. Bacteriological investigation revealed that the causative agent Clostridium perfringens was associated with the disease. Erythromycin, clindamycin and metronidazole were effective, however, ampicillin or penicillin G was more effective and probably the drug of choice for C. perfringens associated haemorrhagic enteritis. Isolates derived from elephant harboured four plasmids (4.1, 14.4, 38.8 and 48.2 kb), while that from pygmy hog carried two plasmids (42.8 and 51.9 kb) . PCR analysis of C. perfringens isolates revealed presence of alpha toxin gene (cpa) and beta2 toxin gene (cpb2). None of the isolates were positive for beta, epsilon, iota and enterotoxin genes. The sequence analysis of partial cpa gene showed 98.6 to 100% homology among the isolates studied. The study confirmed the involvement of beta2 toxin producing C. perfringens type A associated with the haemorrhagic enteritis.[...] Read More.

Keywords: Clostridium perfringens, haemorrhagic enteritis.

2012, 11(1), 1-6;

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Research Article

Fungal xylanase production under solid state and submerged fermentation conditions

Suprabha G. Nair*, Sindhu. R, Shankar Shashidhar

Abstract: Seventy fungal strains were isolated from soils collected from different parts of southern Kerala, India. The strains were screened for xylanase production using Czapek’s agar medium. On the basis of clearing zones formed, 34 fungal strains were selected and identified. Solid state and submerged fermentation were done to identify strains that could produce maximum amount of xylanase, as well as to identify those strains that could produce cellulase- free xylanase under these conditions. All strains produced cellulase along with xylanase in solid state fermentation, while 70% of the strains produced cellulase-free xylanase during submerged fermentation.[...] Read More.

Keywords: Xylanase, Czapek’s agar, solid state fermentation, submerged fermentation.

2012, 11(1), 1-6;

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Research Article

Isolation and characterization of a chlorpyrifos-degrading bacterium from agricultural soil and its growth response

M. Surekha Rani, K.Vijaya Lakshmi* P. Suvarnalatha Devi, R. Jaya Madhuri, S. Aruna, K. Jyothi, G. Narasimha and K.Venkateswarlu

Abstract: A soil bacterium capable of utilizing chlorpyrifos as sole carbon source was isolated by selective enrichment on mineral medium containing chlorpyrifos. The bacterial isolate, designated MS09, was identified and characterized as a strain of Providencia stuartii based on biochemical characteristics and 16S rRNA sequence analysis. Growth studies showed that P. stuartii strain MS09 utilized chlorpyrifos to grow in Luria-Bertani broth containing different concentrations of chlorpyrifos at 50 -700 mg/L. However, the optimum concentration that supported bacterial growth over 24 h was found to be 50 - 200 mg/L chlorpyrifos. When compared with the control, a significant increase in bacterial growth was noted at a low concentration of chlorpyrifos (50 mg/L), whereas at higher concentrations (300 - 700 mg/L) an increased lag phase was observed, without inhibiting growth of the pesticide- utilizing bacterium. A literature survey revealed that no data is available regarding the role of P. stuartii on pesticide biodegradation.[...] Read More.

Keywords: Pesticide, chlorpyrifos, Providencia sp. (MTCC No 8099), biodegradation.

2012, 11(1), 1-6;

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Research Article

Human bocavirus, a real respiratory tract pathogen

Zhenqiang Bi*, Pierre B. H. Formenty and Cathy E. Roth.

Abstract: A new virus was discovered by molecular techniques in respiratory samples collected from young children with respiratory diseases in Sweden in 2005. The virus, named human bocavirus, is genetically related to the bovine parvovirus and the canine minute virus, both of which belong to the bocavirus genus of the parvoviridae family. Recent studies conducted in different countries have shown that HBoV is found in 1.5 - 19% of children with respiratory diseases. HBoV has been observed to be associated with a broad spectrum of both upper and lower respiratory tract diseases, more frequently related to lower respiratory diseases, one third of which is pneumonia. HBoV infection is of worldwide distribution, and a seasonal distribution with a peak in winter and spring is suspected. There is increasing evidence that HBoV is pathogenic for the human respiratory tract, especially in infants and young children, and HBoV has been detected from patients with gastroenteritis. However, given the frequent co-infection with bacterial or viral pathogens, the exact role played by this virus in human diseases still remains disputable. Further investigations, including population- based studies with controlled subjects, are needed to prove its pathogenic potential and epidemiologic patterns.[...] Read More.

Keywords: Respiratory virus, human bocavirus, parvovirus; HBoV; respiratory infection, children.

2012, 11(1), 1-6;

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Research Article

Effect of some chemical preservatives on the shelf-life of sobo drink

*Doughari J. H, Alabi G. and Elmahmood A. M

Abstract: The effect of some commonly used chemical preservatives (benzoic acid, sodium benzoate and sodium sulfite) on the shelf-life of Sobo drink was investigated by isolation of microorganisms before and during its ambient storage for 14 days. Three bacterial species, i.e. Lactobacillus acidophilus, Bacillus subtilis and Bacillus cereus were isolated. L. acidophilus was found only in the samples without preservatives, while B. subtilis and B. cereus were found in the samples with preservatives. Four fungal species, i.e. Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus and Trichoderma sp. were isolated. Trichoderma sp. was isolated only in the samples without preservatives, while A. niger, A. flavus, A. fumigatus were isolated in samples with preservatives. Antimicrobial activities of the chemical preservatives revealed that benzoic acid was the most effective against both bacterial and fungal species, followed by sodium benzoate and sodium sulfite. Of all the samples, only those treated with benzoic acid as preservative remained organoleptically attractive after preservation for 14 days.[...] Read More.

Keywords: Antimicrobial activity, chemical preservatives, Sobo, microorganisms.

2012, 11(1), 1-6;

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Research Article

Production and optimization of thermostable alkaline xylanase by Penicillium oxalicum in solid state fermentation

R. Muthezhilan, R. Ashok and S. Jayalakshmi*

Abstract: The objectives of the present study were Isolation, identification and characterization of xylanase producing fungi, optimization of medium composition and cultural conditions for xylanase enzyme production, production using cheaper sources and extraction and partial purification of extra cellular xylanase enzyme from a potential strain. Xylan has a complex structure consisting of -1, 4-linked xylose residues in the backbone to which short side chains of o- acetyl, -L-arabinofuranosyl, D - - glucuronic and phenolic acid residues are attached. A variety of microorganisms are reported to produce endo xylanases, that can degrade -1,4-xylan in a random fashion, yielding a series of linear and branched oligosaccharide fragments. Totally 69 strains were isolated from Pitchavaram mangroves. In secondary screening, based on the diameter of the clear zone formation in oat spelt xylan agar plates, Penicillium oxalicum was selected and optimized for xylanase enzyme production in solid state fermentation using cheaper sources like wheat bran, rice bran, rice straw, sesame oil cake and wood husk. Maximum enzyme activity was observed in wheat bran. (3.89 U/ml) Optimum pH and temperature for xylanase activity were found to be 8 and 45°C at 3% salt concentration. In purification step, 80% ammonium sulphate saturation was found to be suitable giving maximum xylanase activity. The use of wheat bran as a major carbon source is particularly valuable because oat spelt xylan or birch wood xylan are more expensive, Thus the present study proved that the fungal strain P. oxalicum used is highly potential and useful for industrial production.[...] Read More.

Keywords: Xylanases, solid state fermentation, fungi, optimization, purification.

2012, 11(1), 1-6;

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Research Article

Protein rich ingredients from fish waste for sheep feeding

Mohammed Rahmi,*, Mohamed Faid, MohamedElYachioui, El HassanBerny, Mohamed Fakir and Mohamed Ouhssine

2012, 11(1), 1-6;

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Research Article

Studies on immuno-bioactivities of Nyctanthes arbor-tristis (Oleaceae)

M. Kannan*, A.J.A. Ranjit Singh, T.T. Ajith Kumar, P. Jegatheswari and S.Subburayalu

Abstract: In this study the immunomodulatory potential of an Indian medicinal plant, Nyctanthes arbor-tristis L. (Oleaceae), was investigated. The leaf extracts of N. arbor-tristis is used to treat arthritis, lung injury and some painful conditions such as cancer, chronic fever and rheumatism. An ethanolic extract of N. arbor-tristis (NAEE) was screened in rats for humoral and cell-mediated immune responses. Oral administration of the NAEE to rats at a dose of 50, 100, 150 and 200 mg/kg significantly enhanced the circulating antibody titre when challenged with sheep red blood cells (SRBC) and heat -killed Salmonella antigens. The chronic administration of NAEE increased the total counts of white blood cells (WBC) and potentated the delayed-type hypersensitivity (DTH) reactions. The present study confirms the strong immuno-bioactivities in extracts of Nyctanthes arbor-tristis L.[...] Read More.

Keywords: Immuno-bioactivities, Nyctanthes arbor-tristis, anti inflammatory, humoral immunity, delayed-type hypersensitivity.

2012, 11(1), 1-6;

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Research Article

Antibacterial activity of Senna siamae leaf extracts on Salmonella typhi

Doughari J. H and Okafor N. B

Abstract: The aqueous and organic leaf extracts of the plant Senna siamae, traditionally used for the treatment of infectious disease, were tested for their activity against clinical isolates of Salmonella typhi using the disc diffusion method. The ethanol extracts showed the highest activity (zone of inhibition 10 ± 0.01 mm), followed by acetone extracts (zone of inhibition 8 ± 0.01 mm), while the aqueous extracts showed the lowest activity (zone of inhibition 3.5 ± 0.01 mm) at 40 mg/ml concentration. Preliminary phytochemical studies revealed the presence of alkaloids, saponins, tannins and glycosides. The activities of the extracts were comparable to those of ampicillin, chloramphenicol, cotrimoxazole and ciprofloxacin antibiotics (t-test; p < 0.05) . The antibacterial activities of the extracts against S. typhi did not change significantly when treated at 4, 30, 60 and 100°C for 1 h, but reduced significantly at pH 6 to 10. The MIC and MBC values of the crude extracts (1 - 3 mg/ml) were comparable to those of the tested antibiotics (0.3 - 1 mg/ml) (t-test; p < 0.05). Preliminary purification of the ethanol extracts with hexane, ethyl acetate, chloroform and n-butanol showed that the ethyl acetate fraction possessed the highest activity (zone of inhibition 15 mm), followed by n-butanol fraction (zone of inhibition 2 mm), while the chloroform fraction did not show any activity at 20 mg/ml.[...] Read More.

Keywords: Natural bioactive compounds, Senna siamae, Antibacterial activity, Antityphoid drug, Salmonella typhi, Enteric fever, Antibiotics.

2012, 11(1), 1-6;

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Research Article

Safety control indices for plaa-som, a Thai fermented fish product

Phikunthong Kopermsub, and Sirinda Yunchalard , *

Abstract: This study was aimed to determine chemical and microbiological changes during plaa-som fermentation process. The results have been considered for use as safety control indices to obtain a higher quality and safer plaa-som. The fermentation process can be divided into an initiation stage (samples 1 to 3) and a maturation stage (samples 4 to 9) based on the changes obtained. At the initiation stage, pH remained stable at 6.3 and then rapidly declined during the maturation stage as from 6.3 to 4.5. Total acidity showed a continuous increasing trend from 0.12% (w/w) in sample 1 to 1.17% (w/w) in sample 9. Lactic and citric acids were detected as major acids during the initiation stage in a range of 0.22 - 0.29% (w/w). The main acids detected during the maturation stage, however, were lactic and acetic acids and these reached maximum levels at 2.82 and 0.16% (w/w) in samples 9 and 8, respectively. Substantial discrepancies between total viable counts (TVC) and lactic acid bacteria (LAB) counts were obtained during the initiation stage, particularly in sample1 where the TVC was 2.97 log CFU/g and LAB count was lower than 10 CFU/g. This indicated an existence of undesirable indigenous microorganisms other than LAB. At the maturation stage, the two counts concomitantly increased and no discrepancy was found. Maximum counts of TVC and LAB were 6.83 and 6.72 log CFU/g in samples 6 and 9, respectively. Good practices at particular steps and possible critical control points were noted and proposed for a more controllable plaa-som production process which will guide to a higher standard in both safety and quality consistency of the product.[...] Read More.

Keywords: chemical changes, good manufacturing practices, initiation stage, maturation stage, microbiological changes, organic acids profile, safety control indices, spontaneous fermentation.

2012, 11(1), 1-6;

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Research Article

Microbial community analysis of drinking water sources from rural areas of Zimbabwe

Zvidzai C.*, Mukutirwa T., Mundembe R. and Sithole-Niang I.

Abstract: Traditional methods employing selective, differential and non-selective media were used to isolate and identify different species of bacteria from rural drinking water reservoirs of Mount Darwin district of Zimbabwe. The colony counts from non-selective nutrient agar plates gave an indication of the overall level of bacterial activity from each water sample. Open deep wells, shallow wells and rivers were found to be the most heavily contaminated water sources. Borehole water sources had very low total microbial loads and absent in some of the water samples. The prevalent bacteria found were the Gram negative Escherichia coli, Shigella, Salmonella, Enterobacter aerogenes and one cocci species that was not further characterized. The presence of faecal pathogenic species in the river water and open wells poses epidemiological cases of diarrhoeal diseases in the district studied. [...] Read More.

Keywords: Drinking water, microbial analysis, faecal bacteria, bacteriophages, phenotypic

2012, 11(1), 1-6;

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Research Article

Prevalence of HCCA in patients infected with and without HBV in Maiduguri, Northeast Nigeria over a period of five years

B. B. Ajayi, H. A. Nggada and A. E. Moses*

Abstract: Hepatitis B virus (HBV) infection has been reported as one of the aetiological factors for hepatocellular carcinoma (HCCA). This study reports the prevalence of HCCA in patients with and without HBV in Northeast Nigeria over a period of five years. A total of 114 patients consecutively diagnosed with HCCA and tested for Hepatitis B surface Antigen (HBsAg) at the University of Maiduguri Teaching Hospital (UMTH), between January 1996 and December 2000, were studied. There were 81 males and 33 females, ranging in age between 9 months and above 60 years. Of the 114 patients with HCCA, 86.8% were positive for HBsAg of which males accounted for a higher prevalence of 63.1%, while females accounted for 23.7% (2.7:1). HCCA patients from the fouth decade of life and above were observed with a higher prevalence of HBV infection. Among the HBsAg-negative patients with HCCA, no significant gender difference was observed (p > 0.05). However, 13.2% of patients with HCCA were negative for HBsAg. Viral and non-viral aetiologic factors may play a role in developing HCCA in Maiduguri.[...] Read More.

Keywords: Hepatocellular carcinoma, Hepatitis B virus.

2012, 11(1), 1-6;

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Research Article

Dehalogenase from Methylobacterium sp. HJ1 induced by the herbicide 2, 2-dichloropropionate (Dalapon)

Ng Hong Jing, Aishah Mohd Taha, Rolando V. Pakingking Jr., Roswanira A. B. Wahab and Fahrul Huyop*

Abstract: Heavy industrial activities and agricultural processes require consumption of many halogenated compounds, and release them continuously as pollutants into the environment. These xenobiotics show high toxicity and persistence and cause many problems to the society, soils and ground water. Microbial dehalogenases are involved in the biodegradation of many important chlorinated compounds. A bacterial strain identified as Methylobacterium sp. HJ1 is able to degrade the herbicide 2,2-dichloropropionic acid by removal of the halogen and subsequent metabolism of the product for energy. D,L-2-chloropropionate also supported good growth of the organism but 3-chloropropionate, monochloroacetate and dichloroacetate were not utilized. Cell-free extracts of the 2,2-dichloropropionate-grown bacteria converted 2,2-dichloropropionate into pyruvate with the release of two chloride ions for each molecule of pyruvate formed. This indicates the presence of dehalogenase activity in the cell-free extracts. Only 2,2-dichloropropionate and D,L-2-chloropropionate were inducers and substrates for the dehalogenase. Monochloroacetate and dichloroacetate did not serve as an inducer, whereas 3-chloropropionate was a non-substrate inducer.[...] Read More.

Keywords: Dehalogenase, 2,2-dichloropropionic acid, degradation, Methylobacterium sp.

2012, 11(1), 1-6;

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Research Article

Trichophyton rubrum â€“ the predominant etiological agent in human dermatophytoses in Chennai, India

G. Venkatesan*, A. J. A. Ranjit Singh, A. G. Murugesan, C. Janaki and S. Gokul Shankar

Abstract: The present study was undertaken to find the predominant etiological agent of dermatophytoses among the patients attending the outpatient clinic of Mycology Section, Department of Dermatology, Madras Medical College and Hospital, Chennai. Specimens were collected from suspected patients with dermatophytoses and examined for the presence of fungal elements, cultured, isolated and identified. Among the 90 suspected patients with clinical symptoms of dermatophytoses, 71 (78.9%) were confirmed in culture. Trichophyton genus was accounted for 93% of dermatophytoses, which was shared by Trichophyton rubrum (73.3%) and Trichophyton mentagrophytes (19.7%), followed by Epidermophyton floccosum (4.2%) and Microsporum gypseum (2.8%). It was noted that tinea corporis (64.8%) is the most prevalent infection followed by tinea cruris (26.8%), tinea pedis (5.6%) and onychomycoses (2.8%). T. rubrum was the predominant species responsible for the dermatophytoses, especially tinea corporis in Chennai, Tamilnadu, India. In addition it was also observed that T. rubrum was most predominant species responsible for the chronic dermatophytoses (81.8%). Further work is in progress to understand the protease profile of the isolates with relation to the chronisity of the infection.[...] Read More.

Keywords: Dermatophytoses, Dermatophytes, Tinea, Trichophyton and Skin infections.

2012, 11(1), 1-6;

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Research Article

Characterization of selected strains from Lactobacillus acidophilus and Bifidobacterium bifidum

Kamila Goderska* and Zbigniew Czarnecki

Abstract: The presented study aims to characterize Lactobacillus acidophilus DSM 20079 and DSM 20242 and Bifidobacterium bifidum DSM 20082, DSM 20215, DSM 20239 and DSM 20456 strains. Within the framework of the performed investigations, the author evaluated their biochemical properties, resistance to antibiotics, antagonism towards selected pathogens as well as the effect on their survivability of different environmental conditions with special emphasis on the conditions prevailing in the human gastrointestinal tract. The performed experiments revealed significant differences between the examined bacterial species as well as between strains of the same species. All the examined strains were characterized by diverse biochemical properties, resistance to antibiotics and showed antagonistic action against Helicobacter pylori bacteria. The tested strains of the L. acidophilus bacteria were found to exhibit antagonistic activity against Escherichia coli and Salmonella enteritidis bacteria, although the observed activity was smaller in comparison with the antagonistic activity against H. pylori. These data confirm reports about the antagonistic effect of probiotic bacteria on the growth of pathogenic bacteria. All the examined bacterial strains fulfil the basic criterion expected from probiotic strains, that is, are capable of surviving in the ‘in vitro’ conditions of the gastrointestinal tract, at low pH and in the presence of bile salts.[...] Read More.

Keywords:

2012, 11(1), 1-6;

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Research Article

Antibiotic resistance profile of Escherichia coli from clinically healthy pigs and their commercial farm environments

Chikwendu C. I.*, Nwabueze R. N. and Anyanwu B. N.

Abstract: The study was conducted to determine the antibiotic resistance profile of Escherichia coli isolated from clinically healthy pigs and their commercial farm environments. Differential and selective media were used to isolate a total of 142 E. coli strains from 202 samples. These were tested against 16 antibiotics using the disc diffusion method. The isolates showed high resistance rates to Cefuroxime (89.4%), Nitrofurantoin (89.4%), Tetracycline (74.6%), Ceftazidime (73.9%), Cefotaxime (72.5%) and Cephalexin (53.5%). Rates of resistance to Septrin and Chloramphenicol were moderate (12.7 to 39.4%), while low rates were recorded for Gentamycin (0.09%), Ciprofloxacine (0.08%), Perfloxacine (0.05%), Augumentine (0.06%), Nalidixic acid (0.07%), Streptomycin (0.05%) and Ofloxacine (0.05%). A total of 78 resistance patterns were identified. The high rates of resistance, as well as the large number of resistant patterns recorded in the absence of the use of antibiotics for growth promotion or as prophylactics suggested that antibiotics are not the only selective factors for antibiotic resistance.[...] Read More.

Keywords: Escherichia coli, antibiotics, resistance, clinically healthy, prophylaxis

2012, 11(1), 1-6;

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Research Article

A survey of Salmonella enterica contamination of camel milk in Kenya

Matofari, J. W., Shitandi, A.*, Shalo, P. L., Nanua, N. J., Younan, M.

Abstract: This study was undertaken to conduct a baseline risk analysis of raw camel milk with special emphasis on Salmonella enterica serovars. Cross-sectional studies were designed to investigate the prevalence of S. enterica serovars in a major camel milk production zone of Kenya. A total of 196 samples were assessed for possible presence of S. enterica. The samples included composite milk from the individual camel udders, bulk milk from collection and market centres, faeces, soil and water samples. Of the 196 samples tested, 43% (84/196) were found to contain Salmonella species. Out of the 84, only 31% (26/84) was positively identified as S. enterica. S. enterica was found in all the sample categories that repre-sented the camel milk production environment. The results suggest that raw camel milk contamination by S. enterica was influenced by post-harvest handling of the product rather than camel infection by the pathogen. It was concluded that a need exists to formulate better regulation strategies for the safe handling of camel milk on rural Kenyan farms.[...] Read More.

Keywords: Camel milk; Salmonella enterica, Milk safety, Kenya.

2012, 11(1), 1-6;

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Research Article

Production of indole-3-acetic acid by Rhizobium isolates from Sesbania species

M. Sridevi and K. V. Mallaiah*

Abstract: Rhizobium isolates from root (Sesbania procumbens) and stem nodules (S. rostrata and S. procumbens) of Sesbania species were shown to produce indole-3-acetic acid (IAA) in culture supplemented with L-tryptophan. Production of IAA was maximal after 72 h of incubation when the bacteria reached stationary phase of growth. The cultural requirements were optimized for maximum IAA production. The effect of carbon (1%) and nitrogen sources (0.1%) revealed that glucose and potassium nitrate were best promoters for IAA production over controls. The effect of different concentrations of EDTA revealed that 0.2 gml-1 EDTA increased IAA production. Among the three isolates, maximum amount of IAA was produced by the Rhizobium isolate from S. procumbens. The IAA from this isolate was extracted, purified and identified by thin layer chromatography.[...] Read More.

Keywords: Rhizobium species, Indole acetic acid, Sesbania species, Rhizobium-legume symbiosis.

2012, 11(1), 1-6;

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Research Article

Studies on the antibacterial activity of root extracts of Carica papaya L.

Doughari, J. H.*, Elmahmood, A. M. and Manzara, S.

Abstract: The bioactive compounds of root extracts of Carica papaya L. were extracted, using water and organic solvents, and were investigated for antibacterial activity against some pathogenic bacteria using the cup plate agar diffusion method. The aqueous extracts did not show significant activity, but the organic extracts had significant activity with the methanol extracts demonstrating the highest activity against the test bacteria. The extracts demonstrated higher activities against all the gram-negative bacteria than the gram-positive bacteria tested, with the highest activity (14 mm zone of inhibition) demonstrated against Salmonella typhi. Increase in temperature enhanced the activity of the extracts, while alkaline pH decreased the activity. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the extracts ranged between 50-200 mg/ml. Preliminary phytochemical analyses showed that the extracts contain alkaloids, tannins, saponins, glycosides and phenols. Carica papaya may be used for the treatment of gastroenteritis, uretritis, otitis media, typhoid fever and wound infections.[...] Read More.

Keywords: Carica papaya L., antibacterial activity, phytochemical analysis, antibiotics.

2012, 11(1), 1-6;

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Research Article

Effectiveness of trisodium phosphate, lactic acid, and acetic acid in reduction of E .coli and microbial load on chicken surfaces

F. M. Bin Jasass

Abstract: Procedures for dipping of chicken carcasses in trisodium phosphate (TSP), lactic acid (LA) and acetic acid (AA) were evaluated to determine their effectiveness for reducing E. coli NCTC 10538 and aerobic total counts on the chicken meat surfaces. Chicken portions were dipped in a suspension of E. coli (7 log CFU/ml) for 20 s and kept for 90 min to allow E. coli to get attached to the chicken surface. The chicken portions were then dipped in 8, 10, and 12% concentration of TSP, 1, 2, and 3% concentration of LA, and 0.5, 1, and 1.5% concentration of AA for 20 s each followed by dipping in tap water for 20 s. A sterile template 4 x 4 cm was placed on the chicken surface and then swabbed by swab cotton. The number of E. coli and aerobic total counts were enumerated. The reduction of E. coli on chicken meat surfaces dipped in 8, 10 and 12% of TSP decreased E. coli by 0.5, 1.2 and 1.6 log CFU/ cm2, respectively. The reduction of E. coli on chicken meat surfaces dipped in 1, 2 and 3% LA was 0.5, 1.8 and 2.1 log CFU/cm2 respectively. The reduction of E. coli on chicken meat surface dipped in 0.5, 1.0 and 1.5% of AA had decreased the E. coli counts of 0.7, 1.1 and 1.4 log CFU/ cm2, respectively. The results showed that LA was more effective against E. coli and aerobic total counts than TSP and AA.[...] Read More.

Keywords: Trisodium phosphate, Lactic acid, Acetic acid, E. coli, Aerobic count, Quality, Chicken, Poultry.

2012, 11(1), 1-6;

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Research Article

Incidence of urinary tract infections (UTI) among children and adolescents in Ile-Ife, Nigeria

Aiyegoro O. A.*, Igbinosa O. O., Ogunmwonyi I. N., Odjadjare E. E., Igbinosa O. E. and Okoh A. I.

Abstract: This study was carried out in order to determine the incidence of urinary tract infection in children and adolescents, identify the uro-pathogens responsible for the infection and study the antibiotic sensitivity patterns of the uro-pathogens. Clean voided mid-stream urine samples were collected in sterile universal bottles from 301 children and adolescents between the ages of 5 and 18 years at the Obafemi Awolowo University Teaching Hospital complex (OAUTHC) Ile-Ife, Nigeria from December 2005 – July 2006. Culture plates with bacteria counts greater than or equal to 1x105 cfu-ml-1 were taken as positive, thus indicative of Urinary Tract Infection (UTI). The bacteria isolates were identified based on colony morphology characteristics, Gram stain reaction and biochemical tests using API 20E kits. The identified bacteria were then tested in vitro with standard antibiotics disc to determine their antibiotics sensitivity patterns. The result of this study shows that 36 (11.96%) of the 301 patients studies had UTI. Of the 124 females examined, 28 (22.4%) had positive urine culture while 8 (4.56%) of the 177 males had significant bacteriuria. A total of 36 bacterial isolates were obtained. Escherichia coli constituted the predominant organism and was responsible for (52.77%) of the cases of UTI. This was followed by Klebsiella sp. (25%), Proteus mirabilis (13.89%), Streptococcus faecalis (5.56%) and Pseudomonas aeruginosa (2.78%). The antibiotics sensitivity test revealed a high level of resistant to cotrimoxazole, amoxicillin and colistin as more than 60% of the isolates were resistance to these. This study highlights the presence of multi-resistance P. aeruginosa and poor compliance of the pathogens in vitro to antibiotics commonly used in treating UTI. It is therefore suggested that appropriate antimicrobials be administered to reduce the risk of multiply resistance organisms developing and avert ineffectiveness of antibiotics. Prompt therapeutic intervention is also essential to prevent cases of asymptomatic UTI from becoming symptomatic with resultant damage.[...] Read More.

Keywords: UTI, uro-pathogens, antibiotic sensitivity.

2012, 11(1), 1-6;

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Research Article

Influence of TORCH infections in first trimester miscarriage in the Malabar region of Kerala

Denoj Sebastian, K. F. Zuhara* and K. Sekaran

Abstract: To correlate the prevalence of TORCH (Toxoplasma gondii, Rubella, Cytomegalovirus and Herpes simplex) infections with incidence of abortion in pregnant women in the Malabar area of Kerala, in order to establish basic knowledge for future pregnancy care. Patients attending the Institute of Maternity and Child Health, Calicut Medical College, Kerala were subjected for the study. Seventy one miscarriage cases and thirty normal pregnant women were studied through their medical, clinical, and serological data. Results were analyzed using person’s chi-square test. This study showed that general population of Malabar area has an infection susceptibility of 32.3% to Toxoplasma gondii, 9.6% to Rubella, 3.2% to CMV (Cytomegalovirus) and 61.3% to HSV (Herpes simplex virus) infections. This was revealed through the estimation of TORCH specific IgG. IgM specific to TORCH agents was also studied in abortion cases and was observed as T. gondii- 50.7% (p[...] Read More.

Keywords: Miscarriage, abortion, TORCH infection.

2012, 11(1), 1-6;

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Research Article

Aspergillus species on cassava chips in storage in rural areas of southern Cameroon: their relationship with storage duration, moisture content and processing methods

G. Essono*, M. Ayodele, A. Akoa, J. Foko, S. Olembo, and J. Gockowski

Abstract: A survey was carried out to monitor during a two -month period the incidence of Aspergillus in samples of stored cassava chips traditionally produced in southern Cameroon. Seventy- two samples associated with two forms of chips (cassava balls and cassava pellets) were collected in two locations (Yaoundé and Ebolowa) and 13 Aspergillus species were isolated. In both locations, Aspergillus versicolor was seldom isolated, whereas A. flavus and A. clavatus were most frequently isolated. The level of recovery of isolates obtained was not affected by location and form of chips, but by the duration of storage (P < 0.01) and the moisture content (P < 0.05) . Five core species were identified, which formed more than 70% of the total isolates associated with the samples analyzed. These were A. clavatus, A. flavus, A. fumigatus, A. niger and A. ochraceous. Correlation coefficients computed between pairs of these species based on total isolation figures for the two locations showed that some were significantly associated. A. clavatus, A. niger and A. ochraceous were positively related to one another in a significant way. Similarly, significant correlations, positive or negative, were observed between the moisture content and all core Aspergillus species. The larger number of these toxigenic fungi isolated raises concerns on the potential of stored cassava products as a natural substrate liable to mycotoxin formation.[...] Read More.

Keywords: Aspergillus species, Cameroon, Cassava chips and Survey.

2012, 11(1), 1-6;

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Research Article

Effect of oil-pulling on dental caries causing bacteria

T. Durai Anand*, C. Pothiraj, R. M. Gopinath and B. Kayalvizhi

Abstract: The effect of oil-pulling on the reduction of total count of bacteria was determined. There was a remarkable reduction in the total count of bacteria. The process of oil- pulling reduced the susceptibility of a host to dental caries. The in-vitro antibacterial activity of sesame oil against dental caries causing bacteria was determined. Streptococcus mutans and Lactobacillus acidophilus were found to be moderately sensitive to the sesame oil.[...] Read More.

Keywords: Antibacterial activity, Streptococcus mutans and Lactobacillus acidophilus.

2012, 11(1), 1-6;

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Short Communication

Growth and survival of Salmonella zanzibar in juice and salami stored under refrigerated and room temperature

Chatti Abdelwaheb*, Lamouri Imen and Landoulsi Ahmed

Abstract: The vehicles usually involved in salmonellosis outbreaks are meat, eggs, poultry and milk. Recently, Salmonella outbreaks were reported in some vegetables such as tomatoes and unpasteurized juice. After inoculation of Salmonella zanzibar onto food samples, growth and survival of S. zanzibar in orange juice and salami were monitored. Our results showed that S. zanzibar is able to grow and survive in orange juice and also in salami. However, growth in salami was more important than in the case of orange juice. Storage at 4°C caused a difference in the survival curve when compared to samples (also juice and salami) incubated at room temperature. The present study demonstrated that orange juice and salami can provide a favorable environment for survival and growth of S. zanzibar in spite of their low pH values.[...] Read More.

Keywords: Salmonella, orange juice, salami, survival, refrigeration.

2012, 11(1), 1-6;

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Research Article

Quantitative survey and anti-microbial effect of Piliostigma thonnigii and Khaya ivorensis leaves on traditional dry-yam

Babajide, J. M * and Atanda, O.O

Abstract: A survey was conducted to determine the quantity of local preservatives (‘Abafe’ Piliostigma thonnigii and ‘Agehu’ Khaya ivorensis leaves) used for parboiling yam and the anti-microbial effect of the leaves on dry- yam ‘Gbodo’. Although, the study revealed that 23 g of abafe, 13 g of agehu and a combination of 12.8 g of abafe and 12.3 g of agehu will be required for 1 kg of yam, there were wide ranges between the quantities of yam as well as the quantities of local preservatives used by the processors. Futhermore, there were reduction in the microbial loads of samples parboiled with the leaves (singly or combined) respectively, immediately after processing and after 3 months of storage compared with the control. Thus, P. thonnigii leaves had bactericidal while K. ivorensis leaves had fungicidal effect on the microorganisms encountered during processing and storage of Gbodo.[...] Read More.

Keywords: Quantitative survey, anti-microbial, Piliostigma thonningii, Khaya ivorensis, dry-yam.

2012, 11(1), 1-6;

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Research Article

Immunoglobulin profile of some Nigerians with Schistosoma haematobium infection

O. P. G. Nmorsi*, N. C. D. Ukwandu, C. Isaac, A. O. Egwunyenga and N. H. Olague

Abstract: The preliminary investigation revealed the prevalence of 138(46.9%) out of 294 volunteers screened for the ova of Schistosoma haematobium in their urine samples. Of these, 84(28.6%) had light infection (50 ova/10 ml urine), while 54(18.4%) had heavy infection (> 50 ova/10 ml urine). This difference was statistically significant at ( 2 = 6.52, p > 0.05). The mean immunoglobulin status were as follow: IgE (2141.6 ± 143.7 ng/dL), IgG (13.6 ± 3.53 mg/dL), IgA (3.72 ± 0.149 mg/dL), IgM (2.82 ± 0.48 mg/dL) and IgD (0.12 ± 0.04 mg/dL) . The relationship between the IgM, IgE and the intensities of infection were positively correlated (r = 0.27 and r = 0.65, respectively) . IgG, IgA and IgD showed negative correlation with the intensities of infection (r = -0.65, r = -0.39 and r = - 0.18, respectively). IgG and IgA can be used as markers of light infection, while IgM and IgE can be used as markers for heavy infection. We deduced that the levels of IgG, IgA and IgM, which were depleted in the infected volunteers, compared to the control subjects, which lacked significant protective effects in these infected volunteers. These low levels of IgA, IgG and IgM and high level of IgE may be involved in maintenance of S. haematobium infection in our study area.[...] Read More.

Keywords: IgA, IgD, IgE, IgG, IgM, Schistosoma haematobium, Nigerians

2012, 11(1), 1-6;

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Research Article

Potential commercialization of a microbial medium formulated from industrial food waste

Zvidzai C.* , Muzhinji N., Chidzvondo F., Mundembe R., and Sithole-Niang I.

Abstract: A microbial medium, designated DYSP medium, was produced from food wastes that included defatted soya, clear beer spent yeast, potato solid waste and opaque beer spent grains. Various combinations of the food wastes were used for the media formulations and evaluated for extent of supporting microbial growth of pure cultures. A 3.0 M sodium hydroxide hydrolysis followed by a neutralization process using concentrated hydrochloric acid has been established and standardized for the preparation of the medium. A dry pulverized medium was produced that could be reconstituted in distilled water (dH2O) without settleable solids.The formulated DYSP medium supported the growth of Escherichia coli, Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Aspergillus niger and Saccharomyces cerevisiae. The composition of the medium was 35.45% protein, 5.7% nitrogen, 56.6% ash, 8.6% moisture and 0.012 mg/ml of total reducing sugar. The pH of the DYSP broth was 6.6 when reconstituted in distilled water. Traditional classical microbiological studies demonstrated that the test cultures could grow and retain normal phenotypic and morphological properties when cultured on the formulated medium.The DYSP medium containing ampicillin, isopropyl ß-D-1-thiogalactopyranoside and 5-bromo-4-chloro-3-indolyl-ß-D-galactoside proved to be an equally alternative medium in molecular biology for selection and screening E. coli TG1 cells transformed with pUC18 plasmid. Other preliminary biotechnological results showed that the formulated medium could form a base for studying and optimizing the production of penicillin by P. chrysogenum.[...] Read More.

Keywords: Food wastes, chemical hydrolysis culturing medium, fermentation and molecular biology.

2012, 11(1), 1-6;

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Research Article

Prevalence and antibiotic susceptibility pattern of Staphylococcus aureus from clinical isolates grown at 37 and 44oC from Irrua, Nigeria

Obiazi H. A. K., Nmorsi, O. P. G., Ekundayo A.O. and Ukwandu N.C.D.

Abstract: A survey of the antibiotic susceptibility pattern of Staphylococcus aureus strains from clinical and skin isolates grown at 37 and 44oC respectively were carried out in Irrua Nigeria. Of the 240 different specimens, 50(20.8%) S. aureus isolates were reported. The highest carrier rate of S. aureus (48%) occurred in wound swab while the least (8.0%) was reported on the healthy skin of the volunteers. The susceptibility of the clinical isolates (10.4%) was lower than the isolates from the skin (36.7%) of the volunteers. This difference is statistically not significant (t = 2.087, P[...] Read More.

Keywords: Prevalence, Antibiotic susceptibility, Staphylococcus aureus, Clinical isolates, skin isolates, Nigeria.

2012, 11(1), 1-6;

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Research Article

In vitro antibacterial activity of crude leaf extracts of Mangifera indica Linn

Doughari, J. H.* and Manzara, S.

Abstract: The active components of leaves of Mangifera indica L. were extracted using cold water and organic solvents (acetone and methanol) and were tested against Staphylococcus aureus, Streptococcus pyogenase, Streptococcus pneumoniae, Bacillus cereus, Escherichia coli, Pseudomonas aerugenosa, Proteus mirabilis, Salmonella typhi and Shigella flexnerri using the agar well (cup plate) diffusion method. Both the acetone and methanol extracts inhibited the growth of gram positive bacteria, with acetone extract exerting more activities on all the gram positive bacteria with zone of inhibition between 15 - 16 mm, and a gram negative bacterium S. typhi (14 mm) at 250 mg/ml. Whereas, water extract was not active on any of the bacterial pathogens tested at any of the concentration of the extract used. The activities of the plant extracts on the inhibited pathogens using the zone of inhibition were not as effective as the standard commercial antibacterial disks of gentamicin and erythromycin (t = 2.23, p < 0.05). Increased temperature (60 and 100°C for 1 h) had a multiplier effect on the activity of the extracts, but alkaline pH decreased the activity. Preliminary phytochemical analysis revealed the presence of tannins, glycosides, saponins and phenols. The MIC and MBC of the extracts was in the range of 12.5 - 75 and 25 - 175 mg/ml respectively. There is a basis for the traditional use of the plant as a local health remedy.[...] Read More.

Keywords: Antibacterial activity, MIC, MBC, gram-positive bacteria, gram-negative bacteria, Mangifera indica, extract.

2012, 11(1), 1-6;

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Research Article

Characterization of Clostridium perfringens field isolates, implicated in necrotic entritis outbreaks on private broiler farms in Cairo, by multiplex PCR

Effat, M. M*; Abdallah, Y. A., Soheir, M. F., and Rady, M. M.

Abstract: During the winter of 2006, outbreaks of severe entritis affected many broiler farms in the AL-Fayoum governorate, south of Cairo, Egypt. To identify the causative agent(s), bacterial isolates (14) from the diseased chickens were characterized phenotypically and biochemically. All isolates exhibited characteristics of Clostridium perfringens. Subsequently, molecular typing of the bacterial isolates was performed by multiplex PCR using four sets of primers specific for the genes encoding the C. perfringens , , and toxins, respectively. A single amplicon, corresponding in size to the alpha ( ) toxin-encoding gene (approximately 402 bp), was amplified from all the bacterial isolates. It was therefore concluded that only C. perfringens type A was responsible for the disease outbreaks.[...] Read More.

Keywords: Clostridium perfringens- necrotic entritis – broiler chicken – multiplex PCR.

2012, 11(1), 1-6;

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Research Article

Phytochemical and antibacterial screening of Anogeissus leiocarpus against some microorganisms associated with infectious wounds

A. Mann*, Y. Yahaya, A. Banso and G. O. Ajayi

Abstract: Ethanolic extracts of the leaf, stem and root bark and the combination of the three parts of Anogeissus leiocarpus were investigated for in vitro antibacterial activity against clinical isolates of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa using agar diffusion techniques. The extracts of the plant parts showed higher antibacterial activity against S. aureus (15.80 ± 0.85) than other tested organisms. The plant parts generally were found to contain important bioactive substances such as glycosides, phenols, tannins, saponins, alkaloids, steroids, ellagic acids and anthraquinones. These agents may be responsible for the antibacterial activity of this plant. Keywords: Anogeissus leiocarpus, clinical isolates, antibacterial activity, bioactive.[...] Read More.

Keywords: Anogeissus leiocarpus, clinical isolates, antibacterial activity, bioactive.

2012, 11(1), 1-6;

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Review

Antigenic variation in pathogenic micro-organisms: similarities and differences

Dietmar Steverding

Abstract: Antigenic variation is a process by which pathogenic micro-organisms escape the immune response of their mammalian hosts. By convergent evolution, protozoal, fungal and bacterial pathogens have developed similar genetic mechanisms for true antigenic variation. In this review article, the biology, the surface antigens and their encoding genes, and the molecular mechanisms of antigenic variation of the protozoa Trypanosoma brucei, Plasmodium falciparum, Babesia bovis, Giardia lamblia, the fungus Pneumocystis carinii, and the bacteria Borrelia hermsii, Anaplasma marginale, Neisseria gonorrhoeae, Mycoplasma bovis and Campylobacter fetus are compared.[...] Read More.

Keywords: Antigenic variation, pathogens, micro-organisms, molecular mechanisms, immune evasion.

2012, 11(1), 1-6;

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Research Article

Antimicrobial resistant pattern of Escherichia coli from human clinical samples in Osogbo, south western Nigeria

Olowe O. A, Okanlawon B. M, Olowe R. A and Olayemi A. B

Abstract: We screened 211 clinical samples of which total of 135 Escherichia coli isolates from different human clinical specimens comprising urine, stool, wound swabs, high vaginal swabs, ear swabs and blood obtained from patients at Ladoke Akintola University Teaching Hospital, Osogbo, Osun State, Nigeria. The isolated E. coli were screened for their antibiograms and plasmid profiles. Seven antimicrobial drugs were used during the study. The prevalence of strains resistance to antimicrobials were; Tetracycline (91.6%), Ampicillin (86.7%), Sulphnamide (77.8%) and Gentamicin and Nalidixic acid which were (39.3%) and (4.1%) respectively. A total of seven antibiotic resistance profiles were obtained with over 64% of the isolates showing multi-drug resistance. Plasmids of three size ranges were detected in all of the isolates. Isolates with high multi-drug resistance profiles were found to possess multiple plasmids with large sizes in the range < 6 – 25 kb. Very large resistance levels > 85% were detected against Tetracycline, Sulphnamide, and Cotrimoxazole while Nalidixic acid showed least resistance of 4.1% among the isolates. Majority of the isolates were positive for betalactamase production when subjected to starch paper method. Key word: Escherichia coli, betalactamse, antibacteria resistance.[...] Read More.

Keywords: Escherichia coli, betalactamse, antibacteria resistance.

2012, 11(1), 1-6;

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Research Article

Screening and optimization of metal ions to enhance ethanol production using statistical experimental designs

Mary Anupama Palukurty*, Naveen Kumar Telgana, Hema Sundar Reddy Bora, Shiva Naresh Mulampaka

Abstract: Ethanol production using jaggery was enhanced in submerged fermentation when the effect of metal inducers was studied using the Plackett-Burman and Box-Behnken designs. Saccharomyces cerevisiae (NCIM 3288) was used as the fermenting organism. The Plackett-Burman design was used to initially screen seven of which the four elements were found to have significant effect on ethanol production. In the next stage, Box-Behnken design was used obtain concentrations of metal ion’s that may be supplemented to get maximum ethanol in during production process. It was observed that ethanol yield has increased to 94.8 from 75.4g/l when supplemented with the critical concentrations of salts provided by the model. These were as follows (g/l): FeSO4. 7H 2O 0.0036, MgSO4.7H2O 0.0033, MnCl2. 4H 2O 0.0017 and ZnSO4.7H 2O 0.0026, in the presence of 220 g/l of jaggery supplemented with (NH4)2SO4 2.612 g/l and KH2PO4 3.407 g/l, while the predicted concentration of ethanol as per the model is 95.35 g/l.[...] Read More.

Keywords: Jaggery, ethanol, Plackett-Burman design, Box-Behnken design, metal inducers.

2012, 11(1), 1-6;

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Research Article

Antioxidant status of Nigerian children with Plasmodium falciparum malaria

Nmorsi O.P.G.*, Ukwandu N.C.D. and Egwunyenga A.O.

Abstract: We evaluated the antioxidant status of 148 Nigerian children with Plasmodium falciparum malaria. The mean malarial parasitaemia was 4701.05 ± 2160.53/µL. The mean antioxidant concentrations of the infected children were determined for vitamin A (12.16 ± 1 - 16 µg/dL), vitamin C (0.43 ± 0.03 mg/dL), 5 carotenes (40.96 ± 5.38 µg/dL), and vitamin E (0.45 ± 0.03 mg/dL) . The control subjects had higher mean concentrations of vitamin A (72.12 ± 3.12 µg/dL), and of the 5 carotenes (132.63 ± 22.45 µg/dL), and these differences were statistically significant (X2 = 42.86, P > 0.05 and X2 = 50.64, P > 0.05, respectively). The mean concentrations of vitamin C (1.22 ± 0.31 mg/dL) and vitamin E (1.03 ± 0.48 mg/dL) in the control children were not statistically significant when compared with their infected children (X2 = 0.34, P < 0.05) and (X2 = 0.66, P < 0.05), respectively. The relationship between malarial parasitaemia and the concentrations of vitamin E and the 5 carotenes were positively correlated (r = 0.83 and r = 0.99, respectively) . The levels of plasma vitamin A and vitamin C were negatively correlated with the malarial parasitaemia (r = -0.98, and r = -0.96, respectively). Children within their first 5 years of age had higher malarial parasitaemia (7628.42 ± 3151.42/µL) than those > 6 years (1176.58 ± 956/µL). The children between 1 - 5 years old had lower concentrations of vitamin A (8.89 ± 3.74 µg/dL) and vitamin C (0.28 ± 0.21 µg/dL), while the concentration of the 5 carotenes (44.54 µg/dL) and of vitamin E (0.50 ± 0.16 µg/dL) was higher in these children. In conclusion, the depressed levels of plasma antioxidants in the P. falciparum-infected children suggested lowered immunity of the children, which may contribute to the morbidity and mortality of malaria in our locality.[...] Read More.

Keywords: Vitamin A, vitamin C, vitamin E, antioxidants, Children, Plasmodium falciparum, Nigeria.

2012, 11(1), 1-6;

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Research Article

Retrospective study on the antibiotic resistant pattern of Salmonella typhi from some clinical samples

Doughari, J. H.*, Elmahmood, A. M. and Nggada, H. P.

Abstract: Due to reported cases of antimicrobial resistance by many pathogenic bacteria against many antibiotics worldwide, and the sparse nature of antimicrobial resistance data, a retrospective study was carried out on 744 isolates of Salmonella typhi obtained from 974 samples from four different hospitals in Yola, Adamawa State, Nigeria between 2001-2004 to determine the resistance pattern of S. typhi to the most commonly used antibiotics cotrimoxazole, ciprofloxacin, chloramphenicol and ampicillin. High rates of resistance was found in most of the isolates studied. Resistance rates were 92.3, 88.8, 79.6, 53.5 and 20% to amoxicillin, ampicillin, chloramphenicol, cotrimoxazole and ciprofloxacin, respectively. The high percentage resistance to the antibiotics studied could be attributed to their prevailing usage and abuse in the area under study. The implication of the high percentage resistance recorded for the antibiotics is that only ciprofloxacin will effectively treat S. typhi infections. These results call for nationwide surveillance programme to monitor microbial trends and antimicrobial resistance patterns in Nigeria.[...] Read More.

Keywords: Antibiotics, resistance, surveillance, Nigeria, Salmonella typhi.

2012, 11(1), 1-6;

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Research Article

Dielectric measurement of the resistance of Trichosporon cutaneum against toxic chemicals

Filadia P. Tileva, Lyubov K. Yotova and Gerard H. Markx*

Abstract: Conditioning of cultures involves growing cells in the presence of increasing amounts of a toxic chemical. In order to investigate how conditioning affects a culture’s ability to resist new challenges, the resistance of Trichosporon cutaneum to various toxic chemicals, before and after conditioning to growth on phenol, was investigated by measuring the capacitance of cell suspensions at 0.4 MHz following a toxic challenge. The results show that cells grown on phenol are more resistant to the influence of polar aromatic toxic chemicals such as phenol (log Pow = 1.48) and benzylalcohol (log Pow = 1.1), but less resistant against less polar non-aromatic compounds such as n-octanol (log Pow = 2.9). In reverse, cells grown on glucose were found to be more resistant against n-octanol, but less so against phenol and benzylalcohol. The results indicate that cells, adapted to be more resistant to one type of substance, may become more susceptible to other compounds.[...] Read More.

Keywords: conditioning, adaptation, membrane, Trichosporon cutaneum, capacitance.

2012, 11(1), 1-6;

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Research Article

Evaluation and guidelines for use of polymerase chain reaction-computer database homology comparison (PCR-CDHC) for detection and species determination of human pathogenic microsporidia

Scot E. Dowd* and Jeanette A. Thurston-Enriquez

Abstract: The potential for waterborne disease and zoonotic transmission of at least two species of human pathogenic microsporidia has heightened interest in clinical and environmental detection methods for these organisms. Detection using the polymerase chain reaction (PCR) followed by computer database homology comparison (CDHC) (PCR-CDHC) was reported previously by this research group. As a result, PCR-CDHC has been employed by many research groups around the world for species determination of human pathogenic microsporidia. To validate the CDHC speciation approach, a phylogenetic tree was generated using the small subunit ribosomal DNA sequences (SSU-rDNA) of a large number of microsporidia. An index of similarity was created and used as part of an assessment of CDHCs ability to differentiate between closely related species. Polymerase chain reaction followed by dye termination PCR sequencing and subsequent CDHC of the sequences was performed on 8 species of microsporidia including four human pathogenic strains. The four non-human pathogenic microsporidia tested by this approach were those shown by the phylogenetic analyses to be very closely related to the other human pathogenic species as determined by branch length. In all cases the CDHC approach was able to correctly identify the eight species of microsporidia evaluated. To provide an example of PCR-CDHC, a “universal” and two previously published pathogen-specific microsporidia PCR protocols followed by PCR-CDHC was conducted to assess their ability to detect naturally occurring microsporidia species in swine wastewater. Only one primer set resulted in a PCR-CDHC analysis where presumptive human pathogenic microsporidia was detected. Subsequent CDHC showed these presumptive positive PCR results were actually false positives. With the appropriate primer set, PCR-CDHC proves to be a reliable method that can be used for specific species determination of human pathogenic microsporidia in samples where non-pathogenic species may be present.[...] Read More.

Keywords: Microsporidia, Sequencing, BLAST, PCR, detection.

2012, 11(1), 1-6;

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