Prevalence of extended spectrum pcta-lactamasc producing Escherichia coli from patients diagnosed with urinary tract infections in Olabisi Onabanjo University Teaching Hospital, Sagamu, Ogun State

Abstract

Background: Extended spectrum Beta-lactamascs (ES[JLs) arc variants of beta lactamase enzymes that arc capable of hydrolyzing broader spectrum of beta lactams antibiotics. The enzymes have mutation in the gene at the active site that is believed to be the cause of high Beta lactamase activity. ES^L mediate resistance to all third generation cephalosporin’s, including monobactams. This study was carried out to determine the prevalence of ESBL producing Escherichia coli from patients presenting with eases of urinary tract infection at Olabisi Onabanjo University Teaching hospital between April and June 2016. Method: Urine samples from eases o f U TI were centrifuged and the subnatants were diluted serially up to 10- with sterile distilled water. A lapful of cache of the last two dilutions was streaked on a plate of sterile Eosin Methylene Blue (EMB) agar. The plates were incubated at 37"C for 24 hrs. Plates that clicited growth were sub-cultured and stored for further use. Gram staining and conventional biochemical tests including indole, citrate utilization, hydrogen sulphide utilization, nitrate, catalase and urease tests were conducted on selected distinct colonies with green metallic sheen on the E M B culture plate. Antimicrobial l susceptibility was determined by disc-diffusion method. ESBL detection was done by using the double-disc synergy test. An antibiotic disc of amoxicillin-clavulanic acid (Oxoid, U K) was placed at the center of the plate and discs containing Ceftazidime (CAZ - 30^g) (Oxide, UK), Ceftriaxone (CRO - 30pg) Aztronam (ATM - 30ng) were sited 0.2cm equidistant From the amoxicillin-clavulanic acid disc. After aerobic incubation at 37°C for 18 hours, a clear extension of the edge of the growth inhibition zone of the cephalosporin’s towards amoxicillin-clavulanic ace disc was measured and used as positive in ex o ES|IL production