Isolation of Multidrug Resistant and Extended Spectrum β-Lactamase Producing Bacteria from Faecal Samples of Piggery Farms in Anambra State, Nigeria

Background: Rising global concern about antimicrobial resistance (AMR) has drawn attention to the use of antibiotics in livestock. This research was aimed at isolation and determination of the total coliform bacteria, characterization of the bacterial isolates, screening for multidrug resistant bacteria and the resistant genes from faecal samples of pig farms in Anambra State. Methods: A total of 400 pig faecal samples collected from 40 farms in three senatorial zones of Anambra State were subjected to microbiological analysis and the total coliform bacteria determined. Enteric bacteria from the faecal samples were isolated and identified based on their morphological and biochemical characteristics. Susceptibility of the isolates to different antibiotics were carried out using the standard Kirby‐Bauer disc diffusion method and isolates resistant to cephalosporins were further subjected to Double Disc Synergy Test (DDST) for the phenotypical detection of extended spectrum beta-lactamase (ESBL) production. The ESBL producers were subjected to molecular studies for the detection of ESBL genes using PCR protocols. Results: Mean Total coliform counts of the bacteria from pig faecal samples varied in the 3 senatorial zones. Gram-negative bacteria from the pig faecal samples include the genera Escherichia, Klebsiella, Citrobacter, Salmonella, Enterobacter and Proteus. There is a significant difference in resistance of the isolates to cefotaxime (p = 0.025) and streptomycin (p = 0.012) but no significant difference (p > 0.05) was observed on the rest of the antibiotics tested. Streptomycin (60%) was the most highly resisted while Imipenem (4%) was the least antibiotics. 54.6% of all the organisms were multidrug resistant while 43.7% were ESBL producers. BlaCTX was present in ESBL-producing isolates. Conclusion: There is presence of pathogenic enteric organisms in pig faecal samples harbouring antimicrobial resistant genes. Prudent use of antibiotics in pig farms in Anambra State is therefore recommended to reduce the spread of antibiotic resistance.