Rapid detection and molecular epidemiology of β-lactamase producing Enterobacteriaceae isolated from food animals and in-contact humans in Nigeria

PLoS One. 2024 Apr 11;19(4):e0289190. doi: 10.1371/journal.pone.0289190. eCollection 2024.

Abstract

The emergence and spread of β-lactamase-producing Enterobacteriaceae poses a significant threat to public health, necessitating the rapid detection and investigation of the molecular epidemiology of these pathogens. We modified a multiplex real-time (RT)-PCR to concurrently detect β-lactamase genes (blaCTX-M, blaTEM, and blaSHV) and Enterobacteriaceae 16S ribosomal RNA. qPCR probes and primers were validated using control isolates, and the sensitivity and specificity assessed. The optimised multiplex qPCR was used to screen 220 non-clinical Enterobacteriaceae from food animals and in-contact humans in Southeast Nigeria selected on cefotaxime-supplemented agar plates. Binary logistic regression was used to explore factors associated with the presence of the blaTEM and blaSHV genes in these isolates, and a subset of isolates from matched sampling sites and host species were whole genome sequenced, and their antimicrobial resistance (AMR) and plasmid profiles determined. The sensitivity and specificity of the qPCR assay was 100%. All isolates (220/220) were positive for Enterobacteriaceae ribosomal 16S rRNA and blaCTX-M, while 66.4% (146/220) and 9% (20/220) were positive for blaTEM and blaSHV, respectively. The prevalence of blaTEM and blaSHV varied across different sampling sites (farm, animal market and abattoirs). Isolates from Abia state were more likely to harbour blaTEM (OR = 2.3, p = 0.04) and blaSHV (OR = 5.12,p = 0.01) than isolates from Ebonyi state; blaTEM was more likely to be detected in isolates from food animals than humans (OR = 2.34, p = 0.03), whereas the reverse was seen for blaSHV (OR = 7.23, p = 0.02). Furthermore, Klebsiella and Enterobacter isolates harboured more AMR genes than Escherichia coli, even though they were isolated from the same sample. We also identified pan resistant Klebsiella harbouring resistance to ten classes of antimicrobials and disinfectant. Therefore, we recommend ESKAPE pathogens are included in AMR surveillance in future and suggest qPCRs be utilised for rapid screening of Enterobacteriaceae from human and animal sources.

MeSH terms

  • Animals
  • Anti-Bacterial Agents / pharmacology
  • Enterobacteriaceae*
  • Escherichia coli / genetics
  • Humans
  • Microbial Sensitivity Tests
  • Molecular Epidemiology
  • Nigeria / epidemiology
  • RNA, Ribosomal, 16S / genetics
  • beta-Lactamases* / genetics

Substances

  • beta-Lactamases
  • RNA, Ribosomal, 16S
  • Anti-Bacterial Agents

Grants and funding

The main funding for this study (Grant number: NGCN-2018-242) was provided by the Commonwealth Scholarship Commission in the UK (CSC), awarded to author SOO. Additional financial support was received from the Royal Veterinary College, University of London, awarded to author SOO, and the UK FAO Reference Centre for Antimicrobial Resistance, funded by the Department for Environment, Food and Rural Affairs (DEFRA) and the Department of Health and Social Care's Fleming Fund, awarded to author SOO. The funders played no role in study design, data collection and analysis, decision to publish, or manuscript preparation.