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Hassan Momtaz*, Elahe Tajbakhsh, Behnam Abbasian and Manochehr Momeni
Abstract: Mastitis is one of the common diseases of dairy cattle and an inflammatory response of the mammary glands tissue. Mastitis causes considerable loss to the dairy industry. Among several bacterial pathogens that can cause mastitis, S. aureus is probably the most lethal agent because it causes chronic and deep infection in the mammary glands that is extremely difficult to be cured. The present study was to detect agr group genes in the S. aureus isolated from 360 mastitis milk samples in Chaharmahel va Bakhtiari and Isfahan provinces of Iran via PCR by using specific primers. Among 360 milk samples, 86 samples contained 1250 bp fragment of the 23srRNA gene, 10 samples contained agrI gene, 42 samples contained agrII gene, 19 samples contained agrIII gene and 15 samples contained agrIV gene.[...] Read More.
Keywords: Bovine mastitis, S. aureus, agr group genes, PCR, Iran.
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文章
Fu Xiao Shen, An Chun Cheng, *, Ming Shu Wang, Hai Bin Huang, Chuan Feng Li, Jin Feng Jiang, Ren Yong Jia, De Kang Zhu, and Xiao Yue Chen
Abstract: The aim was to identify the factors affecting synonymous codon usage bias in the newly discovered gC gene of duck plague virus (DPV) CHv strain and a comparative analysis of the codon usage bias in the gC genes of 27 other reference herpesviruses was performed by using CAI, CHIPS and CUSP program of EMBOSS. The results showed that base composition, mutational bias and natural selection were the major determinants of the codon usage variation in the DPV gC gene. The primary codon usage trends in the DPV gC gene showed obvious difference with a strong bias towards the synonymous codons with A and T at the third codon position. Characterization of nucleotide composition in the DPV gC gene was related to dinucleotide usage bias characterized by the variation of CpG islands. The ENc-plot and GC12s-GC3s revealed that the genetic heterogeneity in the gC genes of the 28 herpesviruses were constrained by G + C content. Moreover, the phylogenetic analysis demonstrated that codon usage patterns of the DPV gC gene were phylogenetically conserved and similar to the gC genes of the avian alphaherpesvirinae. Furthermore, comparisons of the codon preferences in the DPV gC gene with those of Escherichia coli, yeast and human revealed that there was a statistically positive correlation between DPV and yeast (r = 0.646, P < 0.05) . The above results could provide useful information for the synonymous codons usage bias of the DPV gC gene and promote the relevant mechanism for evolution, pathogenesis and functional studies in the area of DPV research and possibly studies with other herpesvirus viruses.[...] Read More.
Keywords: Duck plague virus (DPV), gC gene, codon usage bias.
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Nipun Silawat*, Shweta Chouhan, Pramod Sairkar, R. K. Garg, Neetu Vijay and N. N. Mehrotra
Abstract: In this research study, three samples were collected from the T.S. Murthi Udhyan, Obedullahganj out of which two samples were from agriculture field soil and the third sample was from compost. Pure cultures of bacteria were isolated by using serial dilution and spread plate methods. The isolated bacterial cultures were separated according to the morphotypes and then bio-chemically tested. They were further identified with the help of bacteria identification program (PIBWin 2007). The identified bacterial cultures are Achromobacter group F, Acinetobacter calcoacet, Pseudomonas aeruginosa, P. malli, P. putida, P. cepacia, P. shutzeri, P. pseudomalli, P. malli and P. pickettii. The value of Simpson’s index (D) is 0.09, which represented high diversity. Isolated bacteria were inoculated in micro titer plates and Niche overlap index (NOI) was calculated after two days of inoculation. The results of study indicate that direct incubation of samples in micro titer plates produces patterns of metabolic response useful in the classification and characterization of microbial communities. Principal component analysis of colour responses quantified from digitized images of plates revealed distinctive patterns among microbial habitats and spatial gradients within soil and compost sites. Correlation of the original carbon source variables to the principal components gives a functional basis to distinctions among communities. Intensive spatial and temporal analysis of microbial communities with this technique can produce ecologically relevant classifications of heterotrophic microbial communities.[...] Read More.
Keywords: Microdiversity, compost, sole source carbon utilization, testing.
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文章
Chen-Xiaoxi and Chen-Weiliang
Abstract: With a view to exploring whether there was a correlation between a novel antibiotic and a plasmid, the plasmid was eliminated by SDS. Because the elimination of the plasmid had no effect on the bacterium’s producing antibiotic, it was determined that the plasmid had nothing to do with the antibiotic. However, with the plasmid being eliminated, the ability of the bacterium to secrete a kind of adhesive substance was lost, and the phenotype of the bacterium was also changed. This indicated that the plasmid was closely related to this adhesive substance and that the adhesive substance determined the bacterium’s phenotype. In addition, losing the plasmid meant losing life if the bacterium was under adverse circumstances like cold condition. It meant that the function of the plasmid (or the adhensive substance) was to protect the bacterium.[...] Read More.
Keywords: Plasmid, phenotype, antibiotic, viability, bacterium.
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文章
Dilek Satana*, Gonca Erkose Genc and Zayre Erturan
Abstract: Oropharyngeal candidiasis (OPC) is the most common HIV related oral lesion. Most patients are infected with a strain originally present as a commensal of the oral cavity. The resistance of Candida isolates to antifungal drugs is important due to morbidity and mortality. The aim of our study was to investigate the antifungal susceptibility profiles of oral Candida spp which were isolated from HIV-infected patients. In vitro susceptibility tests were performed using the broth microdilution method recommended by the Clinical and Laboratory Standard Institute (CLSI). A total of 67 oral Candida isolates from colonized HIV-infected patients, which were previously isolated and identified were included in this study. MIC ranges were 0.12 - 4.0, 0.12 - 16, 0.03 - 1.0, 0.03 - 1.0, and 0.03 - 0.25 µg/ml for amphotericin B, fluconazole, itraconazole, ketoconazole and voriconazole, respectively. All isolates were fully susceptible to voriconazole. Sixty five (97%) of all isolates were determined fully susceptible to amphotericin B, 66 (98.5%) to fluconazole, 64 (95.5%) to ketoconazole and 50 (88%) to itraconazole. No resistance was detected to fluconazole and voriconazole in oral Candida strains isolated from colonized Turkish HIV positive patients. Antifungal resistance was detected in 8.96% (6 strains) of all isolates tested.[...] Read More.
Keywords: HIV, Candida, oropharyngeal carriage, antifungal agents, antifungal susceptibility.
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Clara Prats*, Jordi Ferrer, Daniel López, Antoni Giró and Josep Vives-Rego
Abstract: Individual-based modelling (IbM) has become a fully incorporated part of predictive microbiology methodologies in the last decade. Previous studies of bacterial culture growth cycle with the IbM simulator INDISIM analysed the evolution of bacterial biomass distribution during the different phases of growth. The predicted forward shift during lag, stability during exponential and backward shift when entering the stationary phase have been experimentally observed in an Escherichia coli batch culture by means of flow cytometry and particle size analysis measurements. In addition, the experimental results were analysed using the product distance, a mathematical tool developed to assess the evolution of cell size distribution. These results confirmed the assumptions about the bacterial lag phase made by INDISIM. Moreover, flow cytometry and particle analysis methods were shown to be useful experimental techniques in combination with IbM simulations when studying the evolution of individual properties during the bacterial growth cycle. This is essential in order to provide a new and consistent interpretation of the dynamics and heterogeneity of cell biomass during the growth cycle.[...] Read More.
Keywords: Bacterial cell cycle phases, biomass distribution, individual-based modelling, flow cytometry, particle size analysis.
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文章
G. Aydemir*, C. Meral, S. Suleymanoglu , F. Karademir and Tarık engör
Abstract: To determine the bacterial etiology of acute middle ear infections in preschool age children. This prospective descriptive clinical study was implemented in Marmaris town between November, 2008 and May, 2009 with 80 cases. Their age ranged from 2 - 6. One fourth of the cases were preschoolers. The diagnosis of acute middle ear infection was confirmed by an otolaryngologist following a pediatrician and paracentesis that was performed. Bacterial culture was done in regular conditions and antibacterial resistance was assessed with disk diffusion method. Streptococcus pneumoniae was the most frequent etiologic agent. It was followed by Haemophilus influenzae (15%) and Staphylococcus aureus (6%) in order of frequency. The penicillin resistance rate of pneumococci was 24%.[...] Read More.
Keywords: Child, infection, middle ear infection.
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O. ’Lanre Olaitan*, O. O. Oyerinde, O. Obiyemi and O. O Kayode
Abstract: The study determined the job stress among primary school teachers in South-west, Nigeria. A total of 624 teachers were chosen as subjects using a multistage sampling technique, and a structure questionnaire was used to gather information from the subjects. Research hypotheses were formulated and inferential statistics of test and analysis of variance ANOVA were employed to analyze significant differences at a = 0.05 level. The differences were significant only for age and gender. Majority of the teachers have headache as symptom of poor health and majority of them engage in watching TV as a strategy for coping with stress. The major source of stress for the subjects is the society. It was recommended among others that, teachers working condition should be improved by planning educational ergonomics and of some social facilities such as: satellite TV; computer connected with Internet; and that the school curriculum should take into cognizance, sporting activities especially for the teachers which should be given a bit of knowledge in health education so to be able to understand themselves and generate more coping techniques for job stress.[...] Read More.
Keywords: Job, stress, ergonomics.
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文章
Pongsak Rattanachaikunsopon* and Parichat Phumkhachorn
Abstract: Carvacrol, a major compound naturally present in oregano and thyme and its precursor, cymene, were tested in vitro for their antimicrobial activity against Edwardsiella tarda, a fish pathogenic bacteria causing edwardsiellosis. When used alone, carvacrol, but not cymene, inhibited the bacterium with the minimal inhibitory concentration (MIC) of 20 ppm. However, cymene was shown to be able to enhance the inhibitory ability of carvacol indicated by the reduction of MIC to 5 ppm when used with 2.5 ppm of cymene. Based on mortalities in 2 weeks after intraperitoneal E. tarda injection, the median lethal dose (LD50) of E. tarda for tilapia (Oreochromis niloticus) was 5.0 × 102 CFU/g of fish. Fish diets supplemented with carvacrol and cymene were also tested for their protective effect against E. tarda infection in tilapia. The results showed that carvacrol (200 ppm) but not cymene (200 ppm) when fed prophylactically decreased the mortality in E. tarda-challenged tilapia. However, carvacrol at the same concentration could cause no mortality of E. tarda infected fish when used in conjunction with 200 ppm of cymene.[...] Read More.
Keywords: Carvacrol, cymene, Edwardsiella tarda, tilapia.
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文章
Selvakumar Dharmaraj*, B. Ashokkumar and K. Dhevendaran
Abstract: Nearly ten isolates of Streptomyces were found to be associated with two species of sponges namely Mycale mytilorum (Annandale) and Tendania anhelans (Lieberkuhn). Among the ten isolates, four strains of white series were selected and characterized by conventional methods and assessed for their antagonistic activity against fish pathogens like Aeromonas hydrophila and Vibrio sp. All the strains showed inhibitory activity against these fish pathogens. The screening of antibacterial substances by the Streptomyces isolates proved the production of highly polyene nature compounds which were observed using criteria like thin layer chromatography (TLC) and spectral analysis. The results of the present investigation revealed that the sponges associated Streptomyces were found to be promising source of antibacterial bioactive substances. It concludes that development of appropriate fermentation and downstream processing technologies would bring out new classes of antibiotic leads.[...] Read More.
Keywords: Antimicrobials, marine Streptomyces, marine sponges.
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