Characterization of multidrug-resistant extended spectrum β-lactamase producing Escherichia coli from commercial swine farms in Ohaukwu local government Area, Ebonyi State Nigeria

Background: The expanding use of antimicrobials in livestock is an important contributor to the worldwide rapid increase in antimicrobial resistance (AMR). The transfer of antibiotic resistance to humans, which usually occurs via the food chain, is of concern for human health. This study assessed the incidence of multiple antibiotic resistance of Extended Spectrum β-lactamase producing Escherichia coli isolated from swine in Ohaukwu local government area of Ebonyi State, Nigeria.

Methodology: A total of 400 rectal and nasal swabs samples were randomly collected from four pig farms and analyzed for the presence of ESBL-producing E. coli. Phenotypic detection of ESBL-producing E. coli was done using double disk synergy test (DDST). Antibiotics susceptibility testing of ESBL-producing E. coli was determined against different classes of antibiotics using Kirby–Bauer disk diffusion method and multiple antibiotic resistance index (MARI) was determined.

Results: Out of 400 swine samples collected, sow/piglets have 164(41.0%), the weaners 140(35.0%) while the finishers were 96 representing 24%. Furthermore, it revealed that out of the 400 samples studied, 157 (39.3%) were E. coli positive, rectal had 85 (42.5%) and nasal had 72 (36.0%). Exactly 19 (12.1%) were ESBL-producing E. coli out of the 157 isolates analyzed, 13 (15.3%); 6 (8.3%) were from rectal and nasal swabs respectively. The ESBL-producing E. coli from swine samples showed varying range of resistance to the antibiotic tested. The ESBL-producing E. coli isolates from rectal swab showed high resistant profile to Amoxicillin/Clavulanic acid, (76.9%); Cefepime, (92.3%); Ceftazidime, (84.6%); Nalidixic acid, (92.3%); and Piperacillin/Tazobactam and Cefoxitin, (100.0%). The ESBL-producing E. coli isolates from nasal swabs were (100.0%) resistance to Amoxicillin/Clavulanic acid, Cefepime, Cefoxitin, Colistin, Nalidixic acid and were (100.0%) susceptible to meropenem. The multi antibiotic resistance index of the isolates ranged from 0.33 to 0.83 with average index of 0.66.

Conclusion: The ESBL-producing E. coli isolates from swine was at high prevalence. This therefore is a big threat to public health and calls for a strict measure in the choice of antibiotics used in swine productions