Prevalence of Extended-Spectrum Beta Lactamase in Entrobacteriaceae Isolated from Urinary Tract Infections in Ardabil, Iran

Urinary tract infections (UTIs) caused by extended-spectrum beta lactamase (ESBL)-producing bacteria have become a growing problem worldwide. The aim of this study was to investigate the prevalence of ESBL-producing bacteria in urine samples of hospitalized patients in Imam Khomeini hospital of Ardabil over a period of October 2011 to August 2012. A total of 400 urinary pathogens isolated from urine samples were included in the study. All isolates were identified by routine biochemical methods and antimicrobial susceptibility testing carried out by Kirby-Bauer method. Confirmatory test for production of ESBLs was performed by the combination disk tests. The results were interpreted according to the recommendation of CLSI. Of 400 isolated bacteria, 267 were E.coli, 39 Klebsiella pneumoniae, 17 Klebsiella oxytoca, 16 Enterobacter cloacae, 15 Enterobacter aerogenese, 6 Enterobacter agglomerans, 8 Enterobacter sakazakji, 3 Citrobacter froundi, 2 Citrobacter diversus, 3 Proteus mirabilis, 4 Edvardsiella tarta, 3 Serratia marcesecens and 17 Morganella morganii all of which then were analyzed. ESBL was detected in 36.75% (147) of isolates. Eighty nine E.coli cases (77.4%), 15 Klebsiella pneumonia (13.04%), 2 Klebsiella oxytoca (1.74%), 3 Enterobacter aerogenese (2.6%), 4 Enterobacter cloacae (3.5%), 1 Citrobacter ferundi (0.86%), and 1 Morganella morganii (0.86%) were detected as ESBLs producers, respectively. Based on the results of this study, broad-spectrum beta-lactamase production in bacterial strains isolated from patients with urinary tract infection was very high and almost 40% of all bacterial species isolates were ESBLs producers. Because of the high prevalence of ESBL-producing bacteria in the urinary tract infections in hospitalized patients of our area, we would strongly suggest that the ESBL production should be considered in these patients.