Abstract

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Antimicrobial resistant bacterial strains have become a global public health challenge affecting both humans and domestic livestock such as cattle, pork and poultry. This research work focused on the characterization of extended spectrum beta-lactamase producing Escherichia coli isolates from swine at Ohaukwu Local Government Area in Ebonyi State, Nigeria. A total of 400 (200 each of rectal and nasal swabs) samples were randomly collected from four swine 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. Plasmid profiling of ESBL-producing bacterial isolates was also determined. Statistical analysis was performed using SPSS 25.0 version software package. 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/culvanic acid, (76.9%); cefepime, (92.3%); ceftaxidime, (84.6%); nalidixic acid, (92.3%); and piperacillin/trazobactam and cefoxitin, (100.0%). The ESBL-producing E. coli isolates from nasal swabs were (100.0%) resistance to amoxicillin/culvanic acid, cefepime, cefoxitin, colistin, nalidixic acid and were (100.0%) susceptible to meropenem. The MARI index of the isolates ranged from 0.33 to 0.83 with average index of 0.66. Plasmid profiling of ESBL-producing isolates revealed presence of plasmids with the molecular weights of 850 bp to 10 kb. In conclusion, ESBL-producing E. coli isolates from swine was at high prevalence with presences of plasmid. Thus, threat to public health that calls for a strict measure in the choice of antibiotics used in swine productions.

Keywords: Extended Spectrum Beta-Lactamase, Escherichia coli, Plasmid, Swine