Microbiology
Sorour Farzi; Reza Ranjbar; Mohammad Niakan; Mohammad Hossein Ahmadi
Abstract
Background & Objective: Escherichia coli (E. coli) is a leading cause of urinary tract infections becoming resistant against beta-lactams and cephalosporins through different mechanisms, including ESBL production due to the presence of ESBL specific genes, including blaCTX-M and blaTEM. The purpose ...
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Background & Objective: Escherichia coli (E. coli) is a leading cause of urinary tract infections becoming resistant against beta-lactams and cephalosporins through different mechanisms, including ESBL production due to the presence of ESBL specific genes, including blaCTX-M and blaTEM. The purpose of the present study was to detect the uropathogenic E. coli strains producing the ESBL.Methods: A total of 100 isolates of uropathogenic E. coli were randomly selected in a period of 6 months and their resistances to a number of antibiotics including amoxicillin, amikacin, gentamicin, ciprofloxacin, ceftazidime, cefotaxime, ceftriaxone, ceftizoxime, nalidixic acid, and nitrofurantoin were determined. Then, DDT test was used to detect the presence of ESBL. Finally, the presence of blaCTX-M and blaTEM resistance genes was analyzed by PCR method.Results: The resistance profile of bacterial isolates to the antibiotics was as follows: amoxicillin: 16.7%, amikacin: 7.8%, gentamicin: 20.3%, ciprofloxacin: 35.5/%, ceftazidime: 35.0%, cefotaxime: 40.0%, ceftriaxone: 41.3%, nalidixic acid: 64.0%, nitrofurantoin: 9.7%, and ceftizoxime: 100%. Of these, 28 isolates (28%) were reported to be resistant to cefotaxime, ceftazidime, and ceftriaxone. In DDT test, 21 ESBL positive cases (21%) were detected. PCR results showed that the presence of blaCTX-M and blaTEM genes in the isolates were 21% and 20%, respectively. Conclusion: Regarding the production of ESBL by some E. coli isolates, phenotypic detection of ESBL-producing isolates is routinely suggested in the laboratories. Likewise, the treatment regimen should be selected regarding the ESBL production to avoid treatment failure.
Ali Jazayeri Moghadas; Gholamreza Irajian; Reza Ranjbar
Volume 4, Issue 3 , June 2009, , Pages 128-132
Abstract
Background: and Objectives: Salmonella infections are endemic in many developing countries with poor sanitary conditions, but emerge sporadically as a serious public health threat in developed countries. Infections with multidrug resistant (MDR) strains of Salmonella have been associated with ...
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Background: and Objectives: Salmonella infections are endemic in many developing countries with poor sanitary conditions, but emerge sporadically as a serious public health threat in developed countries. Infections with multidrug resistant (MDR) strains of Salmonella have been associated with treatment failures. Salmonella spp. resistant to extended spectrum cephalosporins are increasing in prevalence worldwide. The aim of this study was to determine the antimicrobial susceptibility, multidrug resistance and extended spectrum beta lactamase (ESBL) production among clinical isolates of Salmonella spp. during 2007 in Tehran, Iran. Patients and Methods: In this cross-sectional study, fifty Salmonella spp. were identified by API 20E system and serotyped by the slide agglutination test. Disk diffusion test was performed. Double disk synergy test was used as a screening test for ESBL production, using disks of cefotaxime and ceftazidime with and without clavulanic acid. Results: From 50 Salmonella spp. 12 (24%) were S. enterica serotype paratyphi B, 24 (48%) S. enterica serotype paratyphi C and 14 (28%) were S. enterica serotype Typhi. The most susceptibility and resistance were observed to ceftazidime (98%) and amoxicillin-clavulanic acid (96%), respectively. 28(56%) were resistant to 5 or more antibiotics. ESBL production was detected by double disk synergy test in one isolate (2%). Conclusion: Results showed increase in antibiotic and multidrug resistance pattern of Salmonella spp. comparing to previous studies in Iran and other countries.It seems that this is the first report of Salmonella spp. ESBL producing in Iran.
