Antimicrobial resistance and pathogenicity of Escherichia coli isolated from common dairy products in the Lebanon

Ann Trop Med Parasitol. 2009 Jan;103(1):39-52. doi: 10.1179/136485909X384965.

Abstract

In a recent study, bacteria have been isolated from popular Lebanese dairy products, which had been collected in the Beqaa Valley, in north-eastern Lebanon. The foods investigated were two cheeses (shankleesh and baladi) and a dried fermented mixture of yogurt and wheat grains (kishk). Bacterial colonies on McConkey and sorbitol-McConkey agar that showed the morphology of Escherichia coli were biochemically tested and then classified, using PCR-based assays, into the various strains of pathogenic and non-pathogenic E. coli. Some of the confirmed E. coli isolates were proven to be pathogenic, including two identified as E. coli O157:H7. When the pathogenic isolates were tested for their susceptibility to 10 different antibiotics (all commonly used, by clinicians and veterinarians, for the treatment of infections with Gram-negative bacteria), each tested isolate was found to be highly resistant to at least one antibiotic. It therefore appears that, in Lebanon, some popular dairy products pose a public-health hazard, acting as vehicles for the transmission of drug-resistant pathogens.

MeSH terms

  • Animals
  • Anti-Bacterial Agents / pharmacology*
  • Cattle
  • Colony Count, Microbial
  • Dairy Products / microbiology*
  • Dairying
  • Drug Resistance, Bacterial* / genetics
  • Escherichia coli O157 / drug effects
  • Escherichia coli O157 / genetics
  • Escherichia coli O157 / pathogenicity
  • Escherichia coli* / drug effects
  • Escherichia coli* / isolation & purification
  • Escherichia coli* / pathogenicity
  • Humans
  • Lebanon
  • Microbial Sensitivity Tests
  • Polymerase Chain Reaction
  • Statistics as Topic

Substances

  • Anti-Bacterial Agents