MOSP - Macao Scientific Publishers

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Rapid, specific and concurrent detection of Listeria, Salmonella and Escherichia coli pathogens by multiplex PCR in Iranian food

Hamid Reza Tavakoli, Ali Najafi* and Ali Ahmadi

Abstract: We are unable to detect all microorganisms in media. In consequence, molecular methods like PCR based techniques can mend our difficulties in this era. Herein, we describe simultaneous detection of major food-borne pathogens Listeria monocytogenes, Salmonella spp. and Escherichia coli O157:H7. Iranian food materials used for comparison of traditional microbiological methods (such as culture and serology) and multiplex PCR method in the detection of pathogens were prepared from several local restaurant, including eggs, raw milk, Raw kobide, salad, chicken, and cheese. Following DNA extraction, PCR assay were performed, using three specific primer pair. Because of all different sizes of the amplified fragments for each uniplex reaction, we optimized the each primers concentration to achieve a clearly visible band pattern of agarose gel (210 bp for Listeria, 556 bp for E. coli and 942 bp for Salmonella). In conclusion, uniplex and multiplex PCR was considered to perceive detection of the pathogens simultaneously.[...] Read More.

Keywords: Listeria monocytogenes, Salmonella spp., Escherichia coli O157H7, multiplex PCR.

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Evaluation of fluorescent in situ hybridization for rapid diagnosis of enterococcal wound infection

Somayyeh Gharibi, Saeed Tajbakhsh*, Keivan Zandi and Ramin Yaghobi

Abstract: Enterococci are among prominent causes of nosocomial wound infections. Since the rapid detection of causative agents could make earlier administration of choice antibiotics and quick recovery of patients, so the application of rapid diagnostic methods is important. Therefore, this study was designed to evaluate fluorescent in situ hybridization (FISH) for the detection of Enterococcus in wound swab samples. The time needed for FISH procedure is about 3 h. Specimens taken from 33 hospitalized patients were examined by both FISH and culturing procedures. By using conventional culture, 10 of 33 wound samples were culture-positive. Out of these 10 specimens, eight were FISH-positive, but two specimens were FISH-negative for Enterococcus. The remaining 23 wound specimens were Enterococcus negative according to the both methods. Therefore, the specificity of FISH was 100%; however, this method showed 80% sensitivity. Because of high specificity of FISH, the combined application of FISH and cultivation methods would be suggested for detection of enterococci from wound specimens in situations in which rapid diagnosis has an advantage in the treatment of patients.[...] Read More.

Keywords: Enterococcus, wound infection, fluorescent in situ hybridization, FISH.

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Camel pneumonia in Nigeria: Epidemiology and bacterial flora in normal and diseased lung

M. S. Abubakar,*, M. Y. Fatihu, N. D. G. Ibrahim, S. B. Oladele and M. B. Abubakar

Abstract: Respiratory disease is an emerging problem in camels, although information of the normal bacterial flora and bacterial agents implicated in pneumonia is rare in Nigeria. Five hundred lung samples were collected at random from two randomly selected camel slaughter house in Nigeria. Swabs samples were cultured and identified. Arcanobacterium pyogenes, Mannheimia haemolytica and Pasteurella multocida were recovered from pulmonary lesions, however Staphylococcus aureus and other Staphylococcus spp. were the most commonly isolated. Others agents isolated includes: Corynebacterium spp., Streptococcus spp., Klebsiella pneumonia, Micrococcus spp., Bacillus spp. and Proteus spp. It was concluded that, camels harbour in their lower respiratory tract potentially pathogenic agents, that may pose threat to other camels, domestic animals and/or livestock or even human populations. Therefore we suggest transboundary movements of animals be instituted and the camel herd health programme in Nigeria be maintained.[...] Read More.

Keywords: Bacterial flora, camel, epidemiology, Nigeria, pneumonia.

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Isolation and characterization of Newcastle disease virus from ostriches in Iran

M. Ghiamirad*, A. Pourbakhsh, H. Keyvanfar, R. Momayaz, S. Charkhkar and A. Ashtari

Abstract: Newcastle disease (ND) is a highly contagious infection of poultry that causes nervous signs and mortality in young ostriches. This study has been done during two years from 2008 to 2010 in Iran, in order to explore ND in ostriches died following nervous signs, and carcasses of these ostriches examined by different methods including histopathology, bacteriology and virology. No histopathological sign was found in the samples. In bacteriological study no significant bacterial agents were isolated. In virology tests, Newcastle disease virus (NDV) was isolated from 4 brain samples. Intracerebral pathogenicity index (ICPI) and mean death time of chicken embryo (MDT) values of these isolates were between 1.7-1.9 and 38-42 h, respectively, that indicated virulence of these viruses. The reverse transcription-polymerase chain reaction (RT-PCR) test confirmed NDV isolation from samples and its virulence. This study is the first report of NDV isolation from the Iranian commercial ostrich farms. With the respect to high virulence of isolated viruses and endemic pattern of virus in Iran, control program should be organized.[...] Read More.

Keywords: Newcastle disease virus, ostrich, Iran, MDT, ICPI, RT-PCR.

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Degradative activity of bacteria isolated from hydrocarbon-polluted site in Ilaje, Ondo State, Nigeria

Boboye, B., Olukunle, O. F.*, and Adetuyi, F. C.

Abstract: A study was carried out to isolate hydrocarbon -degrading bacteria associated with environmental samples collected from Ilaje coastal area, Nigeria. The samples were analyzed microbiologically using standard microbiological techniques. These organisms were further studied to determine their biodegrading activities on hydrocarbons (diesel, kerosene, petrol) using enrichment medium. The microbial growths were determined using spectrophotometer blanked at 600 nm. The nine bacteria isolated from environmental samples were Enterobacter aerogenes, Pseudomonas aeroginosa, Aerococcus viridian, Clostridium sporogenes, Staphylococcus aureus, Lactobacillus acidophilus, Micrococcus luteus, Streptococcus faecalis and Bacillus sp. It was observed from the result that the length of incubation had significant effect on degradation as well as the cell load. For all the bacteria, there was general increase in length of incubation with the various hydrocarbons. The results showed that there was degradation of oil, mostly between days 1 and 3. It was also observed that there was a gradual decline in the concentration of the broth, between days 4 and 7, which suggests decrease in the bacterial population and that the oil was being degraded. The test on the degrading activity of isolates on hydrocarbon revealed that S. aureus, C. sporogenes, S. faecalis and Bacillus sp. were the best degraders of kerosene, petrol and diesel, respectively. The ability of these isolates to degrade hydrocarbons is clear evidence that their genome harbors the relevant degrading gene. However, an important limiting factor is the slow rate of degradation which often limits the practicality of using microorganisms in remediating hydrocarbon impacted environment. Further research in this area can make a marked improvement.[...] Read More.

Keywords: Biodegrading activity, bioremediation, microorganisms, incubation period, oil spill.

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Combination of high frequency electromagnetic fields with pre heat to inactivate mesophil microorganisms of flexible packed cooked chick and cooked chick meal

Zand N.*, Foroudi F., Mailova E., and Voskanyan A. V.,

Abstract: The effect of high frequency Electromagnetic Induction (EMI) combined with various condition of pre-heating for inactivation of mesophil microorganisms in multilayer flexible pouches has been studied. All samples were filled in pouches and, have been put in (water bath chamber; different condition of pre heating (80°C 5 min, 80°C 10 min, 80°C 15 min, 85°C 5 min, 85°C 10 min, 85°C 15 min) have been done; and ready for EMI sterilization which discharges square-wave pulses with variable voltage 1-20 kV/cm and frequency 8-10 GHz. The spores of these bacteria (gr+) were practically resistant in electric field; however, pre heat caused spore changed its behavior from passive forms (latent) to active forms (vegetative). If cells are cultivated at higher temperature, increasing tendency which can permanently keep fluidity viscosity of the cell membrane before electromagnetic field so EMI efficiency is increased. The populations of mesophil microorganisms depended on type of treatment type of chick type and type of culture. The death ratio of mesophil microorganisms increasing in chick 14200% more than chick meal, chance of negative mesophile microorganism growth in every treatment compares with last treatment increasing 54%. Negative growth in culture "PCA" is 3.3 degree more than culture "PE 2, in culture "PE 2" is 330% more than culture "Cook meat"; how ere these parameter in various thermal processing without EMI was evaluated positive mesophile microorganism growth increasing in chick meal 1905% more than chick type, and chance of passive mesophile microorganism growth in every treatment compares with last treatment decreasing 41% and type culture have no effect on growth of mesophil bacteria.[...] Read More.

Keywords: High frequency electromagnetic fields, electromagnetic induction, flexible packaging, mesophil bacteria, thermal processing, cooked chick, cooked chick meal.

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Antimicrobial activity determination of the gum of Pistacia atlantica Desf. oil

Bachir Raho ghalem* and Benali Mohamed

Abstract: The essential oil from the gum of Pistacia atlantica Desf. grown in Algeria was obtained by the hydrodistillation method, and its antimicrobial activities against the growth of clinical isolates of Staphylococcus aureus, Escherichia coli and Streptococcus pyogenes were evaluated using the agar disc diffusion, the minimal inhibitory quantity (MIQ) determination method and the liquid phase by Maruzella method. The results of the study revealed that essential oil resin of P. atlantica has antimicrobial activity against Gram-positive as well as Gram negative bacteria resistant to commonly used antimicrobial agents, and they were considerably dependent upon concentration.[...] Read More.

Keywords: Gum, Pistacia atlantica Desf. oil, antimicrobial activities, clinical isolates.

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In vivo and in vitro antagonism of Streptomyces sp. RO3 against Penicillium digitatum and Geotrichum candidum

M. C. Maldonado*, C. E. Orosco, M. A. Gordillo and A R. Navarro

Abstract: Streptomyces strains may control postharvest lemon fruit diseases caused by Penicillium digitatum and Geotrichum candidum. Four Streptomyces strains (RO3, MC3, Alem and CE1) were tested and RO3 was the strain with the highest antagonistic activity. Streptomyces RO3 showed a maximum biomass value (2.15 g/L) after 72 h incubation in yeast extract, malt extract, glucose (YMG) medium; in starch casein medium the highest value was 0.477 g/L at 120 h incubation. The metabolites produced in YMG medium showed the maximum inhibition against G. candidum and P. digitatum (19.64 and 62.12% respectively). The inhibitory activity of metabolites decreased after autoclaving. RO3 metabolites have molecular mass higher than 2000 and they have fungicidal action mode against P. digitatum. In vivo assays, RO3 metabolites with wax, totally controlled lemon diseases (mainly sour rot and green mold). This is the first study on Streptomyces to control postharvest lemon diseases.[...] Read More.

Keywords: Streptomyces, Penicillium digitatum, Geotrichum candidum, metabolites, lemon diseases.

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Antimicrobial properties of 4-Carboxyl-2, 6- dinitrophenylazohydroxynaphthalenes

Full Length Research Paper

Abstract: The antimicrobial screening of the monoazo dyes, 4-carboxyl-2, 6-dintropheylazohydroxynapththalene, was carried out as a preliminary test for evaluating their biological potentials. Antimicrobial screening was done with filter paper disc and gauze bandage fabric impregnated with the dyes using 7 microbial isolates: Staphylococcus aureus 382, Candida albicans UBA7, Klebsiella species 864, Escherichia coli V3, Salmonella enterica gallinarum 28 V2, Pseudomonas aeruginosa and Proteus species. Diameters of zones of inhibitions were measured to evaluate the activities of the dyes. The minimum inhibitory concentration of the four title dyes was thereafter estimated using two sensitive strains of S. aureus and Candida albicans. AZ-01 and AZ-04 at a concentration of 5 mg/mL was found to have the highest activities of 20 mm each on S. aureus, comparable to the positive control gentamicin (diameter of 20 mm), using paper disc. With the fabric screening using 5 mg/mL and 10 mg/mL concentration, only the 5 mg/mL AZ-01 and the 10 mg/mL AZ-01 had activities of 10 and 12 mm respectively on S. aureus. On C. albicans, 5 mg/mL AZ-01 and 10 mg/mL AZ-01 had activities of 20 and 24 mm respectively and these were found comparable to the positive control 1% tioconazole. 5 mg/mL AZ-02 and 10 mg/mL AZ-02 had activities of 10 and 14 mm respectively, 5 mg/mL AZ-04 and 10 mg/mL AZ-04 had activities of 16 and 16 mm, respectively. The minimum inhibitory concentration (MIC) done using serial dilution on WHO microtitre plate (96 wells), gave AZ-01 having the highest activity, both on S. aureus and C. albicans with MIC of 15.63 µg/mL, and then AZ-04 with MIC of 23.44 µg/mL. The results of these microbial assays suggest that the investigated monoazo dyes may be useful as potential antimicrobial agents, especially against multidrug resistant S. aureus, in addition to their dyeing properties.[...] Read More.

Keywords: 4-carboxyl- 2, 6-dinitrophenylazohydroxynaphthalenes, antimicrobial properties, multidrug resistant Staphylococcus aureus, MIC.

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Antioxidant and nitric oxide status in patients diagnosed with Echinococcus granulosus

Eser Kilic*, Süleyman Yazar, Gülden Ba kol, Tarik Arti and Dilara Ersayit

Abstract: In the present study, we tried to investigate whether infection with cystic echinococcosis provokes oxidative stress in the host by measuring changes in plasma levels of anti-oxidants enzymes. 23 patients and 25 control individuals were included in the study. Plasma superoxide dismutase [Cu–Zn superoxide dismutases, cytoplasmic form/superoxide dismutase 1] and glutathione peroxidase [Cytoplasmic gluthatione peroxidase 1] activities and plasma nitrite levels were all determined based on the colorimetric methods. Statistically significant decreased cytoplasmic glutathione peroxidase and superoxide dismutase activities with decreased nitric oxide production, which produce superoxide radical was found in patients with cystic echinococcosis. Correlation analysis and statistical evaluation together showed that there was a significant negative correlation between glutathione peroxidase and superoxide dismutase activities (p < 0.001) and also significant negative correlation between glutathione peroxidase activity and nitric oxide level (p < 0.001). In addition, there was a significant negative correlation observed between superoxide dismutase activity and nitric oxide level (p < 0.001). These results clearly indicate a decline in the response to oxidative stresses. It may also be concluded that a decrease in the nitric oxide level can be associated with the low stimulation of the cell mediated immune system.[...] Read More.

Keywords: Cystic echinococcosis, superoxide dismutase, glutathione peroxidase, nitric oxide.

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