JOURNAL OF MICROBIAL WORLD
Year:2009 | Volume:2 | Issue:1|Papers Count:10

Background and objective: Typhoid is a worldwide disease. Salmonella Typhi is the most common agent causing typhoid. It is difficult to treat typhoid due to antibiotics multiple resistance and the bacterium is menace for future epidemic. Vaccination is the most successful method against these diseases. The aim of this study is the isolation of Vi antigen from Salmonella Typhi Ty2 and evaluation of its immunogenicity in animal model.Material and methods: In this research, Salmonella Typhi Ty2 was cultured in Muller Hinton Agar Medium. After harvesting the cells and their suspention into physiologic serum, polysaccharide capsule was extracted by precipitation with cetavlone. Amount of Nucleic acid in the sample was tested with Spectrophotometere at 260 nm and amount of protein were investigated with Bradford method and SDS-PAGE and the Immunodiffusion method was used to study of isolated Vi antigen. In final, immunogenesity of Vi antigen was tested in mouse.Result: Amount of Nucleic acid and protein in the isolated sample were 0.08 mg/ml and 2.59mg respectively. In the SDS-PAGE, smear band of the Standard Vi was similar to isolated sample completely. The precipitation band in the Immunodiffusion method confirmed the presence of Vi antigen. In the study of Vi antigen on the mouse, 80 percent immunity was created. Also injection in Rabbit showed that LPS level in the sample does not cause much fever.Conclusion: With regard to the fact that the human Vaccine of Typhoid is not produced in Iran at present, this method can be used to isolate Vi antigen and this method can be introduced as a vaccine candidate.

Background and objectives: Cicer arietinum is the world`s third ranking and Iran`s first ranking legume in terms of amount of production. Mesorhizobium ciceri is the most important bacteria that has symbiosis with this plant and fixes nitrogen for this legume. The symbiotic Rhizobium of this plant is quite effective in fixing nitrogen molecules. Therefore the study of this phenomenon is very important. Atmospheric nitrogen fixation requires nitrogenase enzyme. nifH, nifD and nifK genes encode three polypeptides of the nitrogenase complex. Material and methods: After isolation of bacteria and culture it, total DNA was isolated by using a standard protocol and it was used as a template. The nifH gene was amplified from genomic DNA by PCR method with appropriate primers.Results: Using two sets of primers nifH1/nifH2 and nifH4/nifD1, amplified products of the expected size were obtained on DNA extracted from M. ciceri. The amplified products obtained with the nifH gene was purified and sequenced. The nucleotide sequences of nifH gene of M.ciceri was performed.Conclusion: 90% homology was shown with the nifH gene in M.loti. This gene has also shown high homology with nifH gene in other Rhizobium species.

Background and Objectives: Johne's disease is a chronic intestinal disease of domestic and wild ruminants that is caused by Mycobacterium paratuberculosis. So that Mycobacterium paratuberculosis is a widespread zoonotic disease. It is necessary to prevent it and the elimination of its agent needs the attention of corresponding managers. The aim of this study is based on the use of Nested PCR as an accurate and rapid method to detection of Mycobacterium paratuberculosis bovine feces.Material and Methods: Fecal samples from 120 dairy cattle were collected and DNA extraction was performed from the samples. Then, samples were evaluated with specific primers for the Mycobacterium paratuberculosis-specific IS900 gene by Nested-PCR assay. Finally, PCR products were electrophoresis on agarose gel.Results: In total, from 120 samples were enrolled in this study, 22 specimen (18.33%) were found positive on the basis of Nested-PCR analysis.Conclusion: Nested PCR technique is considered as a fast, reliable and affordable assay to detect Mycobacterium paratuberculosis.

Background and objectives: Industrial and agricultural activities have led to a substantial release of toxic heavy metals in the environment, which can constitute a major hazard for the ecosystem and human health. Today, the use of microbial biomass for removal of heavy metals from aqueous solutions is gaining increasing attention. This study aims to evaluate the ability of the adsorption of heavy metal Zinc by four different biomasses (activated sludge of the systems of wastewater refining, non-alcohlic carbonated soda industries, milk, herbal oil, and poultry slaughterhouse) and to determine the optimum conditions of pH to eliminate this metal from industrial waste water.Materials and methods: The different values of this industry-activated sludge were added to 250mil Zinc solution of specific concentration. Then in different times, we took sample of the result solution and measured the concentration of Zinc by atomic absorption method. This experiment was repeated by solutions whose pH adjusted to 4 0.2, 5 0.2 and 6.5 0.2.Results: Study of the results delineated that 30mil activated sludge of factories, non-alcohlic carbonated soda, Vegetable oil, Milk and poultry slaughterhouse within 150 min, about 82%, 33.4%, 48.9% and 51.5% decreased the initial concentration of zinc in the solution respectively. The comparison of Zinc absorption ability of active sludge in each industry in different pH showed that all of the mentioned industries sludge with pH 6.5 had the higest ability in Zinc absorption.Conclusion: We can use this material to eliminate Zinc from waste water and their refinement, considering the low cost of the sludge substrast and also its availability. So adjusting the primary pH of solution, the out put of Zinc removal from solution in waste water treatment can be increased.

Background and aim: H. pylori is a spiral shaped gram negative non invasive bacterium which causes peptic ulcer and has an important role in gastric carcinoma and MALT associated lymphoma. The aim of this research is to assess sensitivity and specificity of Rapid urease test in comparison with PCR.Material and Methods: 30 patients (test group) with peptic ulcer disease (PUD) and 30 patients (control group) with Non-Ulcer disease (NUD) were chosen from two centrers of endoscopy in Fars province during 2006. Endoscopy samples were examined by PCR and Rapid urase methods. In this study, PCR test is considered as golden standard test.Results: The assessment of infection sensitivity and specificity ,PPV and NPV Rapid urease test for the test group were detected 76.67%, 80.76%, 69.23%, 85.92%, 60.65% and in control group were 46.67%, 52.94%, 68.18%, 41.62% and 77.17% respectively.Conclusion: This study indicated that the Infection's rate, sensitivity and specificity of Rapid Urase test is acceptable in patients who are not under treatment. But the Infection's rate, sensitivity and specificity of Rapid Urase test is not acceptable in patients who are on Proton Pump Inhibitors (PPI) and treatment with antibiotic. So complementary tests in these patients are recommended.

Introduction and Objectives: E. coli O157:H7 form colorless colonies on SMAC and may be distinguished from intestinal flora. Some Enterobacteriaceae present in gut, also grow on SMAC and are difficult to differentiate and diagnose. Therefore modification and improvement of SMAC medium is necessary to select E. Coli O157. The aim of this study is to improve this medium in order to differentiate this bacterium better.Material and Methods: 250 fecal swab sheep slaughtered in slaughterhouses Shiraz to isolate the bacteria E. coli O157 was selected. Prepared SMAC plates containing from 0.05 mg L-1 ceffexime and 2.5 mg L-1 potasium tellurite as standard (1S) to 6 time standard (6S). Certain pure E. coli O157 EDL933 was plated on SMACs. All plates incubated in 37°C over night. Results: E. coli O157 was grown on all six SMACs, but all plates had grown with the same count in 1S to 3S plats. Some bacteria decreased according to dose of antibiotics. Two and four percent contamination rate was shown high sensitivity in 3 S than 1 S. use of media with high antibiotic deleted extra intestinal bacteria.Conclusion: We recommend using ICT-SMAC medium supplemented with 1.5 and 7.5 mg L-1 ceffexime and potassium tellurte respectively in spite of current SMAC to isolate E. coli O157 from clinical case.

Background and Objective: Development of methods without using plotant and poisonous material and minimum wastes to produce under control nano structures is of nanotechnologist concerns. In this way biologists, by previous knowledge, nano-scale minerals controlled making by microorganism, seeking organism capable making non-organic nanoparticles. The aim of this study is the extracellular production of silver nanoparticles with maximum dimention of 20 nm by Fusarium oxysporum fungi.Materials and methods: After studies to optimize growth condition, Fusarium oxysporum biomass in a medium containing yeast and malt extract is reproduced. After silver nanoparticles production in silver nitrate solution, this nanoparticles are studied by UV-Visible Spectrophotometry and Transmission Electron Microscopy (TEM) methods.Results: Studies showed that when Fusarium oxysporum biomass is put in 10-3 M of silver ions, can produce silver nanoparticles in the form of extracellular.Conclusion: Because of physical and chemical particular properties of silver nanoparticles with maximum diameter of 20 nm of Fusarium oxysporum fungi, its industrial production and applied evaluation is offered.

Background and Objective: Diabet mellitus is a chronic disease. In this disorder, due to abnormal glucose metabolism, direct and indirect complications in many organ systems, including ocular, cardio-vascular, vernal, and cerebral and suppression of immune system have occurred. Decreasing both cellular and humoral immune system is an important factor for opportunistic infections. Prevention and control of these infections and recognition of their frequency and risk factor is very important.Material and Methods: In this study, 118 diabetic patients that admitted in Islamic Azad University hospitals were included. Chief complaint of every patient, important finding in clinical examinations and results of microbial culturing from opportunistic infections had been analyzed.Result: From 118 patients, 65 cases (55%) were female and 53 cases (45%) were male. The average age of patients was 59.6±11.7 years old and mean duration time of disease was 13.6±7.8 years. Thirty-one cases (26.1%) were infected by opportunistic bacterial. From patient's samples (in microbial culturing), 12 cases (38.5%0 Escherichia coli, 9 cases (29%) fungal pathogens, 5 cases (16.3%0 Staphylococcus aurous and 5 cases (16.3%0 Pseudomonas aeruginosa were isolated.Conclusion: Because of high frequency of infections in diabetic patients, using of preventing methods is important. On the other hand, diagnostic and treatment of these infections prevent their complications.