Razi Journal of Medical Sciences

  Background: Urinary Tract Infection (UTI) is the second most common infection in human. Most of UTIs are due to Escherichia coli ( E.coli) and Klebsiella pneumoniae ( K.pneumoniae) . These bacteria are relevant opportunistic pathogens that account for nosocomial infections. Prevalence of Extended-Spectrum Beta-lactamase (ESBLs) in pathogenic bacteria leads to antibiotic resistance and mortality and morbidity in patients. The best method for controlling strains that produce ESBLs is use of standard method for recognizing ESBLs producer strains. The objective of this study was to evaluate and compare the frequency of ESBLs in Escherichia coli and Klebsiella pneumoniae strains isolated from hospitalized and out-patient with urinary tract infection in selective centers from Esfahan.

  Methods: The research was of descriptive type and performed in Al-zahra, Shariaty, and Kashany hospitals and Reference and Mahdieh laboratories during 2009-2010 in Isfahan. According to statistical formula 378 UTI samples were randomly selected . Bacterial identification was performed with microbiological methods and ESBLs production was performed with screening and confirmatory test. For data analysis, Chi square test and Whonet 5.4 software was used.

  Results: From 378 samples, 167 bacteria were from hospitalized cases and 211 bacteria were from out-patient samples. Frequency of E.coli in hospitalized and out-patients was respectively 52% and 64% and frequency of K.pneumoniae in hospitalized and out-patient was respectively 64% and 22%. Frequency of ESBLs in E.coli strains in hospitalized and out-patient was respectively 58% and 17% and frequency of ESBLs in K.pneumoniae strains in hospitalized and out-patient was respectively 64% and 22%.

  Conclusion : The results showed high rate of nosocomial UTI and high frequency of ESBLs in isolated bacteria from hospitalized cases as compared to out-patients that represent high incidence of antibiotic resistant strains in hospitals.