Antibiotic susceptibility of bacteria isolated from pasteurized milk and characterization of macrolide-lincosamide-streptogramin resistance genes

J Food Prot. 2005 Feb;68(2):347-52. doi: 10.4315/0362-028x-68.2.347.

Abstract

The presence of antibiotic-resistant bacteria in pasteurized milk was detected by plating 18 milk samples on selective media containing beta-lactams, macrolides, or a glycopeptide. Most samples contained gram-positive bacteria that grew on agar plates containing oxacillin, erythromycin, and/or spiramycin. The disk-diffusion method confirmed resistance to erythromycin and/or spiramycin in 86 and 65% of the coryneform bacteria and Micrococcaceae tested, respectively. PCR and sequence analysis revealed the presence of an ermC gene in 2 of the 25 Micrococcaceae strains investigated for their resistance to erythromycin and/or spiramycin. None of the 14 corynebacteria strains resistant to erythromycin and/or spiramycin harbored the erm(X) gene. No gene transfer could be demonstrated between the two erm(C) staphylococcal isolates and recipient strains of Enterococcus faecalis JH2-2 or Staphylococcus aureus 80CR5.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Bacterial Agents / pharmacology*
  • Base Sequence
  • Consumer Product Safety*
  • Corynebacterium / drug effects*
  • Corynebacterium / genetics
  • Drug Resistance, Multiple, Bacterial
  • Food Handling / methods*
  • Genes, Bacterial
  • Humans
  • Lincosamides
  • Macrolides / pharmacology
  • Microbial Sensitivity Tests
  • Micrococcaceae / drug effects*
  • Micrococcaceae / genetics
  • Milk / microbiology*
  • Streptogramins / pharmacology

Substances

  • Anti-Bacterial Agents
  • Lincosamides
  • Macrolides
  • Streptogramins