Mediate ampc β-lactamases among escherichia coli, klebsiella spp, and proteus mirabilis isolated from urinary tract infection of subjects in delta state university health centre.

The study was carried out to determine mediate AmpC beta-lactamases among Escherichia coli, Klebsiella spp, and Proteus mirabilis isolated from urinary tract infection from symptomatic subjects in the University Health Center Abraka. Midstream urine was collected from 100 patients having urinary tract infection. The urine sample was cultured using MacConkey agar to isolate gram negative organisms. All isolated organisms were identified by standard cultural and biochemical test.  The antibiotics susceptibility test was done by using Kirby- Bauer disk diffusion method. Screening test for AmpC beta-lactamase was done using disk diffusion method with cefoxitin disc (30µg).  Confirmatory test was done based on phenotypic inhibition test for AmpC beta-lactamase using phenylboronic acid. The occurrence of the uropathogens are E. coli (85%), klebsiella spp (12%) and proteus mirabilis (3%), this shows that E.coli is the most common uropathogen. Highest susceptibility of the isolates was to levofloxacin, ofloxacin, gentamicin, cefepime, nalidixic acid while they show high resistance to cefotaxime, imipenem and augmentin. There was moderate susceptibility to ampiclox, this indicates the prescence of AmpC beta-lactamase as cloxacillin is an inhibitor of AmpC beta-lactamase. The isolates were resistant to penicillins and the cephalosporins except cefepime, this also indicates the presence of the AmpC beta-lactamase enzyme. Zone of inhibition of 18mm is considered resistant and organisms that had the diameter of their zone of inhibition 18mm were selected for confirmatory test. Organisms with zone of inhibition of the cefoxitin disc (30µg) with phenylboronic acid (300µg) 5mm are positive for AmpC beta-lactamase. 80% of Klebsiellaspp, 75% of E.coli and 50% of Proteus mirabilis were positive for AmpC beta-lactamase enzyme. The detection of AmpC beta-lactamase should be practiced as it will contain the spread of organisms possessing this resistance mechanism, help in choosing the right drugs for the treatment and learn about the clinical implications of AmpC beta-lactamase.