Background & Aims: Urinary tract infection (UTI) is one of the most frequently acquired bacterial infections caused by a large genetically heterogeneous group of Escherichia coli, which are called uropathogenic E. coli (UPEC). Cystitis and pyelonephritis are two most common symptoms seen in patients with UTI. The genetic diversity of this organism has hampered the identification of UTI strains and it is unclear whether all UPEC isolates are capable of causing both cystitis and pyelonephritis. Therefore, Careful selection of appropriate genotyping methods is mandatory. The most popular method is Pulsed Field Gel Electrophoresis (PFGE) that is used in the present study to evaluate the genetic patterns of UPEC. Methods: In this cross-sectional study a total of 90 E. coli strains consisting of 48 isolates causing pyelonephritis and 42 isolates causing cystitis in children were analyzed by PFGE and their corresponding patterns were compared. Results: Sixty six PFGE profiles were obtained from the genome of E. coli strains by this genotyping method. Most strains exhibited twelve and thirteen bands and the patterns with eight or nineteen bands had the lowest rate. Genome size of strains was between 1610-4170 kbp. Conclusion: According to these results, it can be suggested that in some cases the strains causing pyelonephritis or cystitis have common patterns and different clinical symptoms could be attributed to different gene factors.

Background: Urinary tract infection is the most common nosocomial infection worldwide. Microorganisms causing urinary tract infections are resistant to most of the antibiotics. Pseudomonas aeruginosa (P. aeruginosa) is one of the major causes of nosocomial infections and its antibiotic resistance leads to medical implications associated with urinary tract infections. The aim of this study was to assess the prevalence of P. aeruginosa strains to identify their in-vitro susceptibility to antimicrobial agents and to determine genetic diversity of them.Methods: Urine samples were obtained from catheterized patients in Shohada and Labafi Nejad hospitals, Tehran, Iran, and cultured by standard loop method. The cultures with more than 105 CFU/ml were assumed as positive. After identification of bacterial species by biochemical tests, susceptibility of each isolate was assessed by disk diffusion method according to Clinical and Laboratory Standards Institute (CLSI) guidelines. In order to analyze bacterial genotypic diversity, pulsed-field gel electrophoresis (PFGE) was performed.Findings: 116 out of 163 urine samples were positive for bacterial isolates. Pseudomonas species were placed in third step of the most frequent isolates. Antibiotic sensitivity was observed against most of antimicrobial agents. Some of strains were genetically similar.Conclusion: This study revealed that isolated strains were sensitive to wide range of antibiotic agents. In addition, common type strains were responsible of causing inter- and intra-hospital urinary tract infections in catheterized patients.

Introduction: Pulsed Field Gel Electrophoresis (PFGE) is one of the best typing methods which is highly effective in molecular epidemiological studies in different areas. All bacterial isolates are typeable by PFGE and the results are highly reproducible. As this technique is very sensitive and the least variation in the parameter leads to lack of result or false positive, in this study we tried to optimize this method and eliminate the technical problems to obtain accurate results for comparison of different strains in epidemiological studies.Material and Methods: To assess the genotype pattern of Escherichia coli strains by PFGE method, we studied different parameters such as concentration of DNA molecules of the sample and their relationship with the enzymes concentration.Results: After different examinations, the best optical density for bacterial suspension in the wavelength of 610 was found to be within 0.6-0.7 nm and the best concentration of XbaI enzyme was 150 units. The appropriate time for proteinase K effect was 7 hours.Conclusion: It seems that the parameters used in this study are the most essential factors in the establishment of an effective PFGE method. With due attention to this experiment, researchers can use this method more efficiently than before for epidemiologic studies and comparison of different strains.

In this report the different methods of pulsed field gel electrophoresis and the parameters such as electrical field geometries, field angles, field strengths, type of buffer and its ionic strength, type of gel and its concentration, and the effect of temperature were considered. Among them a technique called "Contour Clamped Homogeneous Electric Field" was chosen for further studies. Based on this technique, a pulsed field gel electrophoresis system was designed and constructed. Finally, the ability of system for separation of large DNA molecules was examined. Using this system, we were able to separate the compositions of Saccharomyces serevisiae in the molecular weight range of 90 Kbp to 2.2 Mbp.

Background: Antibiotics such as fluoroquinolones are used for treating infections caused by Gram-negative bacteria, including Acinetobacter baumannii strains some time have extended-spectrum b-lactamase (ESBL), but ESBL production is rather rare. Resistance to fluoroquinolones antibiotics is mediated by lactamases and other mechanisms of resistance. The aim of the present study was to investigate of the prevalence of ESBL production and clonal relatedness of A. baumannii in Iran.Materials and Methods: A. baumannii isolates identified from patients at hospitals in Kermanshah, Iran, were studied. The double disk method was used for detection of ESBL production. The susceptibility to different antibiotics was determined by the disk diffusion method (CLSI). Clonal relatedness was determined by pulsed-field gel electrophoresis (PFGE) and processed by Bionumerics 7.0 software. Statistical analyses were performed using SPSS-16.0.Results: This study showed high prevalence of resistance to ampicillin and cefpodoxim (98.1 and 92.3%). Fifty-two of the 84 isolates were identified as ESBL producers. Only colistin and tigecycline remained active against all isolates tested. The PFGE identified eight distinct pulsotypes: A (N=9), B (N=10), C (N=2), D (N=5), E (N=9), F (N=15), G (N=1) and H (N=1). The PFGE profiles A, B and F were believed to be endemic (specially clone F that was dominant across different wards of the hospitals and appeared to be endemic) in the ICU, emergency, pediatric and infection area throughout the years.Conclusion: Early and timely detection of ESBL-producing A. baumannii clones is useful for preventing their spread within the hospital. PFGE analysis is helpful for detection of common strains in different wards and prevention of further spread of these pulsotypes to other hospital environment.

Background: The aim of this study was to determine the MDR isolates and the existence of OXAs genes among MDR isolates of A. baumannii collected from Kermanshah hospitals in west of Iran.Methods: Fourty-two MDR A. baumannii isolates were collected from patients of Kermanshah hospitals. The isolates were identified by biochemical tests and API 20NE kit. The susceptibility to different antibiotics by disk diffusion method (CLSI) was determined. PCR was performed for detection of blaOXA-23-like, blaOXA-24-like, blaOXA-51-like and blaOXA-58-like beta lactamase genes in isolates and clonal relatedness was done by PFGE (with the restriction enzyme ApaI). The patterns were then analyzed by Bionumeric software.Results: This study showed high resistance to ciprofloxacin, piperacillin, ceftazidime and resistance to other antimicrobial agents and more spread of blaOXA-23-like gene (93%) in MDR isolates. Six clones were obtained through PFGE method named in A (10), B (9), C (5), D (4), E (11) and F (3) that clone E was an outbreak and dominant in different wards of the hospitals.Conclusion: An isolate from the emergency ward of the hospitals had indistinguishable isolates PFGE profile and similar resistance profile to isolates from intensive care unit (ICU) proposes that the transmission from ICU to emergency ward probably occurs through patients or hospital staff contact.

Introduction: Acinetobacters especially Acinetobacter baumannii causing nosocomial infections in hospitals intensive care units and can cause a variety of hospital infections such as bacteremia, meningitis, pneumonia and urinary tract infections. There are several molecular techniques for microbial genotyping, among them Pulsed- Field Gel Electrophoreses is introduced as the gold standard for sub typing of bacteria. The aim of this study was investigating the molecular typing of A. baumannii strains with PFGE as well as the relationship between common types available and their antibiotic resistance.Methods: In this descriptive - analysis study, 50 Acinetobacter baumannii were confirmed with cultivation methods and biochemical tests. Then, bacteria were detected using PFGE typing and the results were compared with the results of antibiotic resistance.Results: The results showed that all isolates had multiple resistance. The highest sensitivity was observed for tobramycin (52%), gentamicin (36%) and moropenem (32%).The results of this study showed that A. baumannii strains isolated from Shahrekord hospitals were in seven different genetic patterns that two of these patterns were sporadic and the genetic patterns were different in each hospital.Conclusion: Although variations among strains of Acinetobacter baumannii were observed by using PFGE in Shahrekord, but no epidemic strain was detected among them. In terms of resistance to commonly used antibiotics were also different patterns.

Background and Objectives: Glanders is a serious zoonotic disease caused by Burkholderia mallei. Prevention, control, and treatment strategies of glanders are prerequisites for microbial source tracking. The present study was aimed to analyze the genomic pattern of B. mallei Iranian field isolates by pulsed-field gel electrophoresis (PFGE) typing. Materials and Methods: B. mallei isolates were aerobically cultured in nutrient broth/agar supplemented with glycerol 4% for 48 h at 37°, C. API 20NE identification system was used for the biochemical characterization. Genomic DNA of bacterial isolates was extracted using OIE-recommended protocol. Molecular identification of bacterial isolates was done based on amplification of BimA and IS407-flip genes. PFGE was applied to prepare the genomic pattern of B. mallei isolates. The guinea pig was used as a suitable model for studying the histopathological characterization of B. mallei. Results: In both enzymatic digestion patterns by using Af1II and VspI, we found three different clonal types,І, ) PFGE type of B. mallei Razi 325 strain, І, І, ) PFGE type of Tiger, Kordan, and Oshnavieh strains, and І, І, І, ) PFGE type of Semirom strain. B. mallei Razi 325 was categorized as unrelated strain which was belonged to the different cluster differing more than four bands. Conclusion: PFGE showed more discriminatory power and considerable reproducibility for molecular typing of B. mallei strains in our study. It is standardized the approaches for outbreak detection, pathogen phylogeny, molecular epidemiology, and population studies.