title: Environmental contamination by vancomycin resistant enterococci (VRE) in Swedish broiler production.
abstract: BACKGROUND
  Vancomycin resistant enterococci are a frequent cause of nosocomial infections and their presence among farm animals is unwanted. Using media supplemented with vancomycin an increase in the proportion of samples from Swedish broilers positive for vancomycin resistant enterococci has been detected. The situation at farm level is largely unknown. The aims of this study were to obtain baseline knowledge about environmental contamination with vancomycin resistant enterococci in Swedish broiler production and the association between environmental contamination and colonisation of birds.
  
  
  METHODS
  Environmental samples were taken before, during and after a batch of broilers at three farms. Samples were cultured both qualitatively and semi-quantitatively for vancomycin resistant enterococci. In addition, caecal content from birds in the batch following at each farm was cultured qualitatively for vancomycin resistant enterococci.
  
  
  RESULTS
  The number of samples positive for vancomycin resistant enterococci varied among the farms. Also the amount of vancomycin resistant enterococci in the positive samples and the proportion of caecal samples containing vancomycin resistant enterococci varied among the farms. Still, the temporal changes in environmental contamination followed a similar pattern in all farms.
  
  
  CONCLUSIONS
  Vancomycin resistant enterococci persist in the compartments even after cleaning and the temporal changes in environmental contamination were similar among farms. There were however differences among farms regarding both degree of contamination and proportion of birds colonized with vancomycin resistant enterococci. The proportion of colonized birds and the amount of vancomycin resistant enterococci in the compartments seems to be associated. If the factor(s) causing the differences among farms could be identified, it might be possible to reduce both the risk for colonisation by vancomycin resistant enterococci of the subsequent flock and the risk for spread of vancomycin resistant enterococci via the food chain to humans.
authors: National Veterinary Institute, Uppsala, Sweden. oskar.nilsson@sva.se
authors: Oskar
authors: O
authors: Nilsson
authors: Christina
authors: C
authors: Greko
authors: Björn
authors: B
authors: Bengtsson
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D002432:Cecum / Q000382:microbiology; D002645:Chickens / Q000382:microbiology*; D015169:Colony Count, Microbial; D016983:Enterococcus / Q000187:drug effects / Q000302:isolation & purification / Q000502:physiology*; D004783:Environmental Microbiology; D006799:Housing, Animal; D008826:Microbial Sensitivity Tests; D013548:Sweden; D020713:Vancomycin Resistance