Frogs host faecal bacteria typically associated with humans

Can J Microbiol. 2017 Jul;63(7):633-637. doi: 10.1139/cjm-2017-0119. Epub 2017 Apr 17.

Abstract

Tree frogs commonly access drinking water tanks; this may have human health implications. Although amphibians might not be expected to host mammalian faecal indicator bacteria (FIB), it is possible that they may have human FIB on their skin after exposure to human waste. We collected faeces and skin wash from green tree frogs (Litoria caerulea) from a natural environment, a suburban site, and a suburban site near a creek occasionally contaminated with sewage effluent. We used molecular techniques to test for FIB that are routinely used to indicate human faecal contamination. Enterococci colonies were isolated from both faecal and skin wash samples, and specific markers (Enterococcus faecium and Bacteroides thetaiotaomicron) were found in frog faeces, demonstrating that these markers are not human- or mammalian-specific. Bacteroides thetaiotaomicron was detected in frogs from both natural and urban sites, but E. faecium was only associated with the sewage impacted site.

Keywords: animals; animaux; drinking water; eau potable; eaux usées; qualité de l’eau; sewage; water quality.

MeSH terms

  • Animals
  • Bacteroides thetaiotaomicron / genetics
  • Bacteroides thetaiotaomicron / isolation & purification*
  • Drinking Water / microbiology
  • Drinking Water / standards
  • Enterococcus faecium / genetics
  • Enterococcus faecium / isolation & purification*
  • Feces / microbiology
  • Humans
  • Ranidae / microbiology*
  • Sewage / microbiology
  • Water Microbiology*
  • Water Quality

Substances

  • Drinking Water
  • Sewage