JOURNAL OF MICROBIAL WORLD
Year:2010 | Volume:3 | Issue:3 (8)|Papers Count:6

Background and Objectives: Cutinase belongs to serine hydrolase family that is used for elimination of environmental pollutions due to its special structural and functional properties and applications. In this study, cutinase gene was isolated from indigenous thermophiles Thermobifida fusca and was cloned in E. coli.Material and Methods: Sampling was performed from forest soils in the north of Iran. Thermobifida fusca bacteria were isolated with suitable cultures under optimized conditions (pH 10 and T=62oC). After primer designation, cut1 gene was isolated from bacterium and then, was cloned in pBluescript sk vector and was introduced into E. coli DH5a. The colonization was confirmed based on enzymatic digestion and sequencing.Result: Based on BLAST software, there was 98% and 96% similarities were obtained with cut1 and cut-1.KW3, respectively.Conclusions: Based on broad functions of the enzyme on various substrates and its ability for synthesis of various polyester compounds, this enzyme has an important role in environmental decontamination.

Background and objective: Pasteurella multocida exist commensally in respiratory track of a variety of wild and domestic animals. Serotypes A and D are responsible for pneumonia in goats and sheep, and Fimbriae, adhesions, capsule, toxin, iron uptake factor and outer membrane protein are its important virulence factors. The aim of this study was to design a multiplex PCR for fast and simultaneous detection of more important virulence factors of P. multocida isolated from sheep and goats as well as their capsular typing and identification.Materials and Methods: Totally 500 nasal swabs were collected from the goats and sheeps suspected to respiratory signs of pasteurellasis. After isolation abd detection of P. multosida by biochemical examination, the bacteria were assayed by specific primers for identification of major important virulence factors and their capsular typing.Result: Capsular typing of the isolates by PCR showed two capsular types A, D with 83.8% and 6.4% prevalence, respectively. The results also showed that 23 (74.19%), 21 (67.74%), 21 (67.74%) and 24 (77.4%) of the isolates were positive for presence of toxA, hgbA, ptfA and ompH genes, respectively.Conclusion: The most isolated P. multocida from goat and sheep were toxigenic, and capsular type A was the most common isolates in the Fars province. The remarkable high prevalence of toxA and ompH among the afflicted sheep and goats may imply to important role of these genes in epidemiology and virulence of P. multocida. Furthermore the high prevalence of P. multocida typeA harbor toxA gene can be attributed to its important role in the respiratory infection.

Background and Objectives: A wide range of extraintestinal infections in humans and vertebrate animals are created by the extraintestinal E. coli strains (EXPEC), including APEC (Avian pathogenic Escherichia coli) and UPEC (urinary tract infection in humans). This study aimed to survey presence of eight involving virulent genes of APEC and UPEC strains in human extraintestinal E.coli strains to support the hypothesis that these genes in human APEC and UPEC were originated from avian APEC and UPEC strains.Materials and Methods: A total of 100 and 105 Escherichia coli samples were collected from patients with urinary tract infection and the infected chickens with colibacillose, respectively. After DNA extraction, Multiplex PCR was used for the presence of genes astA, iss, papC, iucD, tsh, vat, cva / cvi (related to strain APEC). Correlation between APEC and UPEC were analyzed by chi-square test.Results: The frequency of astA, iss, irp2 and papC genes in UPEC strains isolated from patients with urinary tract infection were 13%, 11%, 33% and 3%, respectively. The genes iucD, tsh, vat, and cva / cvi were observed in only one of the isolated strains. All genes were observed in all avian strains.Conclusion: presence of astA, iss, irp2, papC genes in both APEC and UPEC strains confirmed their role in extraintestinal infections. Between them, iss gene (the most common isolated gene) and irp2 gene (with 33% frequency in of UPEC) are more likely the most important pathogenic factors in the E. coli strains.

Background and objective: Campylobacter spp. are important causative agent of gastric infection worldwide, and contaminated water and foods are the major transmission factors of this bacterium to human. The major purpose of this study was isolation, identification and characterization of Campylobacter spp. and Arcobacter spp. from the samples obtained from Caspian Sea in the North of Iran.Materials and methods: 263 water samples were collected throughout four seasons. Campylobacter spp. and Arcobacter spp. were isolated using standard methods and were identified by Phenotyping tests. Finally, the identification of these strains was verified by PCR method.Result: Foloowing phenotyping tests and their confirmation with molecular technique, totally seven Campylobacter jejuni strains and 14 Arcobacter butzelri strains were identified. Based on the results, the prevalence of this bacterium in the coastal waters of the Caspian Sea were evaluated as 2.66 and 5.32 percent.Conclusion: It is the first time that Campylobacter jejuni and Arcobacter butzelri were isolated from Caspian Sea. The epidemiologic studies regarding to the ways of their entrance in an environment and their maintenance in the habitat assist activists to control the water qualification and prevention from distribution of infections.

Background and Objectives: Malva silvestans and Lawsonia inermis are widely used in the East Azerbaijan folk medicine. The effective compounds of these plants describe probabely their biological activities and therapeutic activity. In this study, methanolic extract of these plants were used to detect antioxidant and antimicrobial activity.Material and Methods: Superoxide anion radical scavenging assay was used for antioxidant activity test in which the superoxide anion radicals were generated by a pyrogallol auto oxidation system. The antimicrobial activity of methanolic extract of these plants was tested by disc diffusion method against three enteric microorganisms. The minimal inhibitory concentrations (MICs) of methanolic extracts were determined, too.Results: The used assay for assessment of antioxidant activity in order to determine the accumulation of superoxide radicals in total extract of plant was not appropriate. However, for antibacterial assays, all three bacteria were susceptible to methanolic extract and showed 4 to 15 mm zone of inhibition.Conclusion: Although the total extracts of plants used in this study had appropriate antimicrobial activities,their antioxidant effects was not significant.

Background and Objective: Wheat brown rust is one of the most important diseases caused by Puccinia triticina Erikson. In recent years, determination of Brown rust pathotypes based upon rDNA ITS1 sequencing has become more interested. The aim of this research was evaluation the similarities and differences ITS1 of ribosomal DNA between the brown rust pathotypes collected from different geographical and climatically parts of Iran.Material and Methods: The DNA extraction was performed on urediniospore of collected sample. The ITS5 and Rust 2 primers were used for PCR amplification of rDNA ITS1 region, and the amplified products were sequenced directly. The accession numbers of isolate sequences were registered in GeneBank. Multiple sequence alignments and identification of tandem repeats were carried out by MPEG4 and DNA MAN softwares.Results: The results showed %0-1.2 differences between ITS1 sequences. Different mutations, includingdeletion, insertion, number of tandem repeat and some differences in ITS1 length were observed in DNA sequences..Conclusion: Despite differences in pathotype, phenotype and geographical distributions of isolates, only limited differences were observed in ITS1 sequences. Because no logical correlation was observed between differences in pathotypes and ITS1 sequences, this rDNA region cannot be used as marker for determination of pathotypes of these fungi.