Extended Spectrum - Lactamase (ESBL) producing Escherichia coli strains is reported to be the cause of community and hospital acquired infections. E. coli responsible for urinary tract infection (UTI) have capability to produce ESBLs in huge amounts. Bio film are group of microorganisms encased in an exopolymer coat. The present study was undertaken over a period of one year from November 2012 to August 2013 to study the prevalence of ESBL and bio film producer E. coli among UTI patients attending the Raja Muthiah Medical College and Hospital (RMMCH), Annamalai University at Chidambaram, South India. Three hundred and twenty four (79.80%) isolates of E. coli were obtained from 478 urine samples and thereafter were subjected to susceptibility testing according to the Clinical and Laboratory Standard Institute (CLSI) guidelines using 14 different antibiotics. All the samples were confirmed by standard microbiological methods. Additionally molecular characterization of 16S rRNA sequence was carried out. They were further screened for ESBL production by double disc approximation test (62%) and CLSI combination disk method (38%) respectively. Of the 324 isolates of E. coli, (38%) were found to be ESBL producer. E. coli exhibited 57 and 53% susceptibility to levofloxacin and imipenem respectively. The resistant to amikacin, nitrofurantoin tetracycline, nalidixic acid and chloramphenicol were observed among ESBL producers. The antibiotic resistance patterns of E. coli and the correlation between ESBL and biofilm producing E. coli was also determined. There is a need for continued surveillance of antimicrobial resistance among ESBL and biofilm producing E.coli and concluded the resistance may be realted to β-lactamase production of the biofilm bacteria.
