Genetic characterization of antibiotic resistance and virulence factors in Enterococcus spp. from Japanese retail ready-to-eat raw fish

Food Microbiol. 2014 Apr:38:62-6. doi: 10.1016/j.fm.2013.08.010. Epub 2013 Aug 24.

Abstract

Little information is available on the diversity and distribution of resistance and virulence factors in enterococci isolated from retail fish. In this study, 200 samples of retail ready-to-eat raw fish (sashimi) collected from the Japanese prefecture of Hiroshima were analyzed for incidence of Enterococcus spp. We recovered 96 enterococcal isolates from 90 (45%, 90/200) samples. Fifty-six strains were identified at the species level: E. faecalis (n = 31), E. faecium (n = 7), E. casseliflavus (n = 7), E. gallinarum (n = 3), E. phoeniculicola (n = 4), E. raffinosus (n = 2), E. saccharolyticus (n = 1), and E. gilvus (n = 1). Twenty-five (26%, 25/96) strains carried antibiotic resistance genes. These included the tet(M), tet(L), tet(K), erm(B), msr(A/B), aph(3'), and blaZ genes, which were detected in 12.5%, 9.3%, 2%, 14.5%, 1%, 1%, and 2% of isolates, respectively. The virulence genes gelE and asa1 were detected in 31 and 24 E. faecalis strains, respectively. Both genes were detected in one E. faecium strain. In conclusion, this is the first study to underscore the importance of sashimi as not only a reservoir of Enterococcus spp. carrying resistance and virulence genes, but also a reservoir for unusual Enterococcus spp.

Keywords: Antibiotic resistance; Enterococci; Raw fish; Virulence.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Bacterial Agents / pharmacology*
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Drug Resistance, Bacterial*
  • Enterococcus / drug effects
  • Enterococcus / genetics
  • Enterococcus / isolation & purification*
  • Fast Foods / microbiology*
  • Fishes
  • Food Contamination / analysis*
  • Food Contamination / economics
  • Japan
  • Seafood / economics
  • Seafood / microbiology*
  • Virulence Factors / genetics*

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Virulence Factors