Brazilian Journal of Microbiology
On-line version ISSN 1678-4405
CHAH, K.F. and OBOEGBULEM, S.I.. Extended-spectrum beta-lactamase production among ampicillin-resistant Escherichia coli strains from chicken in Enugu State, Nigeria. Braz. J. Microbiol. [online]. 2007, vol.38, n.4, pp. 681-686. ISSN 1678-4405. http://dx.doi.org/10.1590/S1517-83822007000400018.
One hundred and seventy-two ampicillin-resistant E. coli strains isolated from commercial chickens in Enugu State, Nigeria, were screened for beta-lactamase production using the broth method with nitrocefin® as the chromogenic cephalosporin to detect enzyme production. Beta-lactamase producing strains were further examined for extended-spectrum beta-lactamase (ESBL) production using the Oxoid combination discs method. One hundred and seventy (98.8%) of the 172 ampicillin-resistant E. coli strains produced beta-lactamase enzyme. Sixteen (9.4%) beta-lactamase producers were phenotypically confirmed to produce ESBLs. Six of the ESBL producing strains were only detected with ceftazidime versus ceftazidime/clavulanate combination while ten of the ESBL producers were detected with cefotaxime versus cefotaxime/clavulanate combination. Chicken may serve as a reservoir of ESBL-producing E. coli strains which could be transferred to man and other animals.
Keywords : Ampicillin-resistant; Escherichia coli; beta-lactamase; extended-spectrum.