Abstract

DETECTION OF EXTENDED-SPECTRUM BETA–LACTAMASE–PRODUCING ESCHERICHIA COLI FROM MARKET READY CHICKENS IN A SOUTHERN NIGERIA METROPOLITAN CITY

Emmanuel A. Afer, Malachy C. Ugwu, Jude N. Okoyeh*, Ugochukwu M. Okezie, Moses N. Ikegbunam

ABSTRACT

Background: The persistent use of antibiotics in farm animals to prevent, treat, and control diseases is of public health importance. Extended spectrum Beta-lactamases (ESBLs) are enzymes that break down the beta- lactam ring present in beta-lactam antibiotics. The aim of this study was to detect the prevalence of Extended-Spectrum Beta-Lactamase producing Escherichia coli from market ready chickens in a southern Nigeria metropolitan city. Methods: A total of 253 gastrointestinal track (GIT) and stool samples were collected from market ready chickens from two local chicken markets (Ochanja and Kara) from August to December 2019. A total of 107 (42.3 %) E. coli were isolated after the samples were aseptically cultured and screened via cultural and biochemical tests. The isolates were subjected to antibiotic susceptibility studies using disk–diffusion method. Thirty-one (30%) isolates that were found resistant were further subjected to phenotypical ESBL confirmation using Modified Kirby – Bauer Double Disc Synergy Test (MDDST). The screen positive isolates were further subjected to PCR assay. Results: Of the 107 isolates subjected to multiple antibiotic tests, thirty-one (30 %) isolates were resistant to multiple antibiotic susceptibility tests. Eighty-six (80.4%) of the isolates exhibited high resistance to Amoxycillin-Clavulanic (AMC) while 68 (63.6%) were highly susceptible to nitrofurantoin (NIT). The cefuroxime showed higher intermediate activity of 25 (23.4%). The Multiple Antibiotic Resistant Index (MARI) of 0.5 was obtained in 25 (24%) of the isolates. Twenty-nine (27.1 %) isolates were confirmed ESBL positive which comprise 11 (38%) from GIT and 18 (62%) from stool. The prevalence rate of 27.1% was obtained for the ESBLs producing E. coli. Plasmid curing showed non-cured isolates. PCR gel electrophoresis showed the DNA bands of the antibiotic resistant genes of the E. coli isolates. Of the three ESBL genes evaluated (bla-TEM, bla-SHV and bla-CTX-M), 18 (62%) of the samples harbored bla-TEM resistant genes while the bla-SHV and bla-CTX-M genes were not seen from any isolates. Conclusion: From the findings of this study, it can be inferred that there is an increase in ESBL E. coli isolates in Nigerian livestock with multiple resistance to 3rd generation cephalosporins and some other classes of antibiotics; there is also a rising prevalence the ESBL producers in this metropolitan city. In addition, our study indicates the possibility of a more complexity in the epidemiology of the ESBL-producing bacteria. We therefore suggest that other studies from other parts of Nigeria are needed to evaluate the overall antimicrobial sensitivity of ESBL-producing bacteria and the molecular epidemiology of the resistant genes for comparison with already isolated genes from other parts of the world. The scenario of increased ESBL production indicates the adverse consequence of the widespread and indiscriminate use of antibiotics in animal production.

Keywords: Enterobacteriaceae, E.coli, Extended-Spectrum Beta-Lactamase (ESBL), Modified Double Disc Synergy Test (MDDST), Antibiotic Resistance, Plasmid curing, Polymerase Chain Reaction (PCR).