Journal of North Khorasan

Abstract Background & Objectives: Production of β -lactamases especially extended spectrum β -lactamases (ESBLs) by bacteria is one of the emerging health problems in the world. The prevalence of these enzymes varies greatly within different geographical areas and is changing over time. The purpose of this study was to determine the prevalence of ESBL producing bacteria among the urinary Enterobacteriaceae isolates and detection of blaPER gene from two selected hospitals in Mashhad. Material & Methods: In this cross-sectional study, 100 Enterobacteriaceae isolates were collected from urine samples of inpatient and outpatient referred to 17-Shahrivar and Qaem hospitals from November 2010 to January 2011. Bacteria were identified by differential biochemical tests. Isolated bacteria were evaluated for antibiotic susceptibility. Double-disk approximation and phenotypic confirmation tests of ESBL production were performed according to CLSI (Clinical and Laboratory Standards Institute) guidelines. Molecular detection of blaPER gene was carried out by polymerase chain reaction using specific primers. Results: Out of 100 bacterial isolates, 27 (27%) were ESBL producers without plasmid mediated blaPER. gene. Resistance to ampicillin, cefotaxime, ceftazidime and cephalothin among ESBL producing isolates was higher than non-producers (p<0.05). ESBL producers in comparison with non-producers were resistant to gentamicin, co-trimoxazole, and nitrofurantoin and there was significant difference for resistance to gentamicin and co-trimoxazole (p < 0.05). Conclusion: Results shows that ESBL production among Enterobacteriaceae isolates in the studied community is relatively high blaPER gene was not found among isolated strain therefore, production of β-lactamase is related to other types of ESBLs among isolated Entrobacteriaceae