EVALUATION OF EXTENDED SPECTRUM beta-LACTAMASE (ESBL) IN URINARY ISOLATES OF ESCHERICHIA COLI AND KLEBSIELLA PNEUMONIAE

Urinary tract infection are most prevalent infection worldwide, Escherichia coli and Klebsiella pneumoniae are commonly implicated in causing such infection. These bacteria produce large amount of ESBLs and make treatment difficult with betalactam group of antibiotics. ESBLs producing bacteria also show resistance to other group of antibiotics, hence knowledge of ESBL producing bacteria and their susceptibility pattern is helpful in selection of appropriate antibiotic for treatment of UTI patient. Current study was aimed to evaluate presence of ESBL producing E. coli and Klebsiella pneumoniae from urinary isolates and their susceptibility pattern. METHODS Between October 2014 to December 2014, 725 Urine specimens were received in the Department of Microbiology, Tertiary Care Centre of Central India. The samples were cultured on UTI chrome agar (Hi-Media) with the standard calibrated loop (Diameter 0.04mm) by semi-quantitative method and the isolates with significant bacteriuria (>= 10(5) CFU/ml) were included in study. Antimicrobial susceptibility test was carried out using various antimicrobial discs by Kirby Bauer disc diffusion method as per the recommendations of CLSI. Initial screening was done using ceftazidime (30 mu g) and cefotaxime (30 mu g) discs as per CLSI recommendation. Confirmation of ESBL production was done by Phenotypic Confirmatory Disc Diffusion Test (PCDDT) using ceftazidime (30 mu g) and ceftazidime + clavulanic acid (30 mu g + 10ug) disc as per guidelines of CLSI (2014). RESULT Out of a total of 725 urine specimens investigated for significant bacteriuria, 93 (12.82%) E. coli and 28 (3.8%) K. pneumoniae were isolated. Initial screening revealed 74 (79.56%) isolates of E. coli and 18 (64.28%) isolates of K. pneumoniae as probable ESBL producers. Further testing by PCDDT method confirmed 29 (31.18%) of E. coli and 5 (17.85%) of K. pneumoniae isolates as ESBL producers, making a total of 34 (36.95%). These ESBL producing uropathogens showed maximum resistance to cotrimoxazole (100%) and maximum sensitivity to carbapenem group of antibiotics (100%). CONCLUSION Our study showed emergence and occurrence of ESBL producing E. coli and Klebsiella pneumoniae in urinary isolates. 100% sensitivity to carbapenem group of antibiotics was found among ESBL producer advocate there use in UTI patients. Monitoring of ESBL production and antimicrobial susceptibility testing are necessary to avoid treatment failure in patients with UTI.