Multidrug resistant Escherichia coli from fresh produce sold by street vendors in South African informal settlements

Int J Environ Health Res. 2022 Jul;32(7):1513-1528. doi: 10.1080/09603123.2021.1896681. Epub 2021 Mar 11.

Abstract

The aim of this study was to assess the prevalence of commensal and pathogenic Escherichia coli on informally sold fresh produce in South Africa, who harbour and express antimicrobial resistance genes and therefore pose indirect risks to public health. The majority (85.71%) of E. coli isolates from spinach, apples, carrots, cabbage and tomatoes, were multidrug resistant (MDR). Resistance to Aminoglycoside (94.81%), Cephalosporin (93.51%), Penicillin (93.51%) and Chloramphenicol (87.01%) antibiotic classes were most prevalent. Antibiotic resistance genes detected included blaTEM (89.29%), tetA (82.14%), tetB (53.57%), tetL (46.43%), sulI (41.07%), sulII (51.79%), aadA1a (58.93%) and strAB (51.79%). A single isolate was found to harbour eae virulence factor. Moreover, E. coli isolates were grouped into the intra-intestinal infectious phylogenetic group E (28.57%), the rare group C (26.79%), the generalist group B1 (21.43%) and the human commensal group A (16.07%). Presence of MDR E. coli represents a transmission route and significant human health risk.

Keywords: Antimicrobial resistance; antimicrobial resistance genes; diarrheagenic virulence genes; phylogenetic grouping.

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Drug Resistance, Multiple, Bacterial / genetics
  • Escherichia coli Infections* / epidemiology
  • Escherichia coli* / genetics
  • Humans
  • Microbial Sensitivity Tests
  • Phylogeny
  • South Africa

Substances

  • Anti-Bacterial Agents