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Ziadi Manel,*, M’hir Sana*, Kbaier Nedia, Hamdi Moktar and Ferchichi Ali
Abstract: Date Palm sap is a fresh juice called “Legmi” widely produced and consumed in Southern Tunisia. The aim of this research was to study microbiological group’s distribution present in 10 palm sap samples, and to select Lactic acid bacteria (LAB) with suitable properties for use as starter cultures in sap lactic fermentation. Microbiological analysis showed high load in fresh palm sap. Mesophilic aerobic bacteria varied from 6.07 to 8.57 log cfu/ml, coliforms ranged from 3 to 6.78 log cfu/ml, yeasts between 3 and 8.47 log cfu/ml and LAB from 5.36 to 8.47 log cfu/ml. Ten strains were chosen randomly to study the acidifying activity when growing in palm sap. These strains, tentatively identified by API 50CHL, were divided into two groups: Leuconostoc mesenteroides subsp. mesenteroides and Lactobacillus delbrueckii subsp. delbruckii. All the strains were considered as fast acidifier since pH was higher after 6 h of fermentation. The higher acidifying strains KH3 (L. delbrueckii) and 5B4 (L. mesenteroides), were used to inoculate sap in pure culture. During the fermentation, pH decreased from 6.94 and 6.36 for 5B4 and KH3, respectively, to about 4.0±0.1 after 24 h of fermentation for both strains. Total titrable acidity increase from 0.2 and 0.4% for 5B4 and KH3 respectively to around 3.0%. The application of these strains as starter cultures in the production of fermented palm sap could be investigated on further studies.[...] Read More.
Keywords: Date palm sap, legmi, lactic acid bacteria, starter culture.
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Full Length Research Paper
Abstract: The objective of this study is to investigate the prevalence and determine the antimicrobial susceptibility pattern of YERSINIA species in beef meat and chicken meat samples in different seasons. In this study 379 pieces of beef and chicken meats were examined for the presence of YERSINIA species between April 2007 and March 2008. 25 g of homogenized food samples was pre-enriched in PBS then it was cultured on cefsulodin-irgasan-novobiocin (CIN) agar. Susceptibility testing of bacterial strains was performed at 28˚C by the agar diffusion method. YERSINIA spp. was isolated from 60 of 379 (15.8%) beef meat and chicken meat samples. Y. ENTROCOLITICA was found in 48 of 60 (80%) positive samples. The rate of other 3 YERSINIA spp, Y. FEREDERIKSENII, Y. INTERMEDIA, Y. KRISTENSENII, were 7(11%), 4(6%) and1 (0.01%) out of 60 isolates, respectively. 98% of isolates were susceptible to choloramphenicol and gentamicin. The most antibiotic resistance belongs to cephalothine (98%). Our results showed that isolation ratio of Y. ENTEROCOLITICA and the other species is higher in cold climates. The majority of isolates were resistant to cephalothine. The most active pharmacologic agents were chloramphenicol, gentamicin and trimetoprim.[...] Read More.
Keywords: Yersinia enterocolitica, antimicrobial susceptibility, beef meat, chicken.
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Full Length Research Paper
Abstract: Sixty Malaysian CITRUS TRISTEZA virus (CTV) isolates were characterized by bi-directional polymerase chain reaction (BD-PCR) and restriction fragment length polymorphism (RFLP) analysis of their coat protein (CP) gene. In BD-PCR analysis, 392-bp fragments were amplified from seven isolates. The other 53 isolates produced only 320-bp fragments. RFLP patterns of RT-PCR products of CP gene digested with HinfI restriction enzyme were similar to I-IV, VI-VII and two new groups. Isolates AMK1, AMJ12, AMT38, AMT39 and AMT43 could not be classified when they were compared to any standard CTV digest pattern. These isolates produced a unique restriction pattern with two fragments of 210 and 300 bp and isolate AMI61 produced different restriction pattern with three fragments of about 100, 270 and 300 bp. Therefore these isolates were designated as Groups IX and X. These results suggest that CTV populations in Malaysia contain new genetic variants.[...] Read More.
Keywords: Citrus tristeza virus (CTV), strains, coat protein (CP) gene, restriction fragment length polymorphism (RFLP), bi-directional PCR, Malaysia.
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Lautert, C.*, Ferreiro, L., Jesus, F. P. K., Zanette, R. A., Mahl, D. L., Alves, S. H. and Santurio, J. M.
Abstract: The yeast Malassezia pachydermatis is part of the normal cutaneous microflora of most homoeothermic vertebrates. However, under certain conditions as high humidity, seborrheic skin, corticotherapy and immunodeficiency, it can become pathogenic and cause dermatopathies. The pathogenic role of the genus Malassezia seems to be related to physical, chemical and immunological disturbances and to the production of enzymes, including lipases, phospholipases and hydrolases. The Api- Zym ® system is a semiquantitative method designed for the study of 19 enzymatic activities of tissues, cell suspensions, biological fluids, microorganisms, soil and others. Herein, the use of the Api-Zym system in 30 M. pachydermatis isolates detected the presence of the phosphohydrolases: acid phosphatase and naphtol-AS- BI-phosphohydrolase among all isolates, independently of the clinical sign associated to the animal. The knowledge of the enzymatic profile of M. pachydermatis aims to contribute to the comprehension of the role of each enzyme in the pathogeny of this yeast.[...] Read More.
Keywords: Malassezia pachydermatis, enzymes, Api-Zym®, enzymatic profile, dogs.
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Nethathe B. B. and Ndip R. N.,*
Abstract: Medicinal plants contain a variety of chemical substances with important therapeutic properties that can be utilized in the treatment of human diseases. Hydonora africana is used in folklore remedies for the treatment of diarrhoea, dysentery, kidney and bladder complaints among other ailments; hence we assessed the in vitro antimicrobial activity of this plant against three bacterial species (Helicobacter pylori ATCC 43526, Helicobacter pylori PE 252C, Staphylococcus aureus NCTC 6571 and Aeromonas hydrophila ATCC 35654). The agar well diffusion method was used to determine the susceptibility of bacterial strains to crude extracts of the plant. The minimum inhibitory concentration (MIC50) and minimum bactericidal concentration (MBC) of the active crude extracts were determined by the microdilution test. Ciprofloxacin (0.0125 mg/mL) was used as positive control. The presence of phytochemicals was also assessed using standard methods. Results were analyzed statistically by the one-way ANOVA test. Hydnora africana demonstrated antimicrobial activity against all the organisms with a mean zone diameter of inhibition ranging from 0 to 22 mm. The MIC50 of the extracts ranged from 0.078 to 2.5 mg/mL and MBC ranged from 0.78 to 25 mg/mL. Phytochemical assay revealed the presence of alkaloids, tannins, flavonoids, saponins and steroids in the extracts. It is concluded that H. africana may contain compounds with therapeutic activity.[...] Read More.
Keywords: Hydnora africana, medicinal plant, minimum inhibitory concentration, minimum bactericidal concentration, phytochemicals.
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文章
Farshid Kafilzadeh*, Parvaneh Sahragard, Hooshang Jamali and Yaghoob Tahery
Abstract: Petroleum hydrocarbons are species of dangerous contaminants in nature. Scientists are looking for many years to find solution for removing contaminants from the soil and water environments. Today, the use of microorganism, for removing crude oil pollution from contaminated sites (bioremediation) is considered by scientists. The purpose of this research is to isolate and identify hydrocarbons degrading bacteria from Shiraz Refinery soil. In this study, nutrient agar (NA) and mineral salt agar (MM2) were used as basic cultures. Using the Techniques Replica plating, we transferred colonies on NA surface to the MM2 agar. For spraying hydrocarbons on the MM2 agar surface, we used spray plating technique. Finally we have identified different bacterial genera by using biochemical tests and morphological study. Upon examination on morphological studies and biochemical tests, it is determined that these strains belong to bacterial genera as follows: Bacillus, Corynebacterium, Staphylococcus, Streptococcus, Klebsiella, Escherichia, Acinetobacter, Alcaligenes, Shigella. Enterobacter. It is also discovered that these bacteria can break down Biphenyl, Naphthalene, Camphor and Phenenthrene. The results showed that Biphenyl, Naphthalene, Camphor and Phenanthrene were decomposed by 22, 23, 34 and 23%, respectively. Bacillus was 69% of the bacterial population and accounted as the most dominant bacterial genus. Statistical analysis showed that there is a significant relationship with the level of 0.05 among the station, the numbers, and the diversity of Gram-positive bacteria.[...] Read More.
Keywords: Degrading bacteria, camphor, bioremediation, Bacillus, Shiraz Refinery.
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Xianfeng ZHOU*, Jianxin GAO, Yaojian HUANG, Songzhe FU and Haiying CHEN,
Abstract: Morbidity and mortality of infant infections caused by contaminated powdered infant formula (PIF) have been reported worldwide, and pathogens like Enterobacter sakazakii and Klebsiella pneumoniae are important causative agents. To evaluate the prevalence of antibiotic resistance in E. sakazakii and K. pneumoniae that caused PIF contamination in Chinese market, all the isolates from PIF were analyzed for detecting resistance to antibiotics. 30 PIF samples were randomly purchased in Chinese market in 2009 and 7 E. sakazakii and 6 K. pneumoniae isolates were obtained from 8 samples (26.7%), the isolates were evaluated for antibiotics susceptibility by disk diffusion technique as recommended by the Clinical Laboratory Standards Institute (CLSI). Susceptibility results showed that each isolate had different levels of resistance to - lactam antibiotics, while sensitive to fluoroquinolones and aminoglycosides. One K. pneumoniae and one E. sakazakii isolate almost resisted all Cephalosporins chosen; the double-disk synergy test (DDST) showed these two isolates producing extended spectrum -lactamase (ESBL). This is the first report of ESBL-produing in E. sakazakii from powdered infant formula in China.[...] Read More.
Keywords: Klebsiella pneumonia, Enterobacter sakazakii, disk diffusion, antibiotic resistance, extended spectrum -lactamase (ESBL).
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O. A. Terry Alli*, Ogbolu D. Olusoga, S. A. Adedokun and O. E. Ogundare
Abstract: Legionella is a ubiquitous water environmental organism. Isolation/detection of Legionellae has been reported worldwide. However, there is no reported isolation of Legionellae in countries in Africa with the exception of South Africa. The aim of this study was to survey the surface, ground waters and air conditioner water systems (ACWs) in Osogbo, Nigeria for the presence of Legionella pneumophila by cultural isolation method. A total of 313 water samples from the streams (surface water), wells (groundwater) and ACWS were cultured on buffered charcoal yeast extract (BCYE) medium. The isolates were identified by Gram staining techniques, biochemical tests and demonstration of pore forming activity. Polymerase chain reaction for amplification of 0.52 kb fragment of the part of dot/icm region of L. pneumophila was used for the final identification. The results obtained showed that the prevalence of L. pneumophila from streams (8%) was statistically significant when compared to wells (1%) (Chi square, P < 0.05). L. pneumophila was not isolated from any of the water samples taken from air-conditioner water systems. The study concludes that L. pneumophila is present in natural aquatic environment in Nigeria.[...] Read More.
Keywords: Cultural isolation, Legionella pneumophila, Nigeria.
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F. Mollaamin*, M. Noei, M. Monajjemi and R. Rasoolzadeh
Abstract: In this paper, we performed quantum mechanic calculations on structures of fMet-tRNA and fAla-tRNA. Comparing the results structure design was done by formalizing the amino acid and attaching in to the adenine nucleotide of tRNA. The performed calculations are Opt, SCRF, NBO and NMR.[...] Read More.
Keywords: Natural bond orbital (NBO), fMet-tRNA, NMR, Opt, SCRF, fAla-tRNA.
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Sina H., Baba-Moussa F., Ahoyo T. A., Mousse W., Anagonou S., Gbenou J. D., Prévost G., Kotchoni S. O. and Baba-Moussa L.*
Abstract: A wide range of clinical samples were screened for identification of Staphylococcus aureus, their antibiotic sensitivity profile and the production of different leucotoxin and epidermolysins was evaluated. Out of 2,040 biological samples (collected from pus, urine, sperms, genital, catheter and blood of hospitalized and extra-hospital patients) screened, 123 pure cultures of S. aureus colonies were isolated. 48.78% of S. aureus were resistant to methicillin (MRSA), while 78% of them were isolated from extra-hospital patients. The S. aureus isolated from urines, pus and blood produced Panton and Valentine leukocidin (PVL) toxin, while the leucotoxin lukE-lukD was exclusively encountered by S. aureus isolated from pus samples. None of the bacterial colony isolated produced epidermolysin toxins A and B. In addition, 3.25% of MRSA and 8.13% of methicillin sensitive S. aureus (MSSA) produced PVL respectively. Our results indicated high frequency rate of MRSA in extra-hospital screened samples isolated from various types of infection. This high resistance rate combined with toxin production increases the virulence of S. aureus colonies and put therefore at risk the life of the patients in developing countries where auto-medication is not controlled. There is the need to instruct the population in order to avoid further widening of MRSA territory.[...] Read More.
Keywords: Staphylococcus aureus, Panton-Valentine leukocidin (PVL), antibiotic, infection, methicillin-resistant Staphylococcus aureus (MRSA), Benin.
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