Abstract
Food-producing animals may be a reservoir of vancomycin-resistant enterococci (VRE), potentially posing a threat to animal and public health. The aims of this study were to estimate the faecal carriage of VRE among healthy cattle (n = 362), pigs (n = 350), sheep (n = 218), and poultry (n = 102 flocks) in Switzerland, and to characterise phenotypic and genotypic traits of the isolates. VRE were isolated from caecum content of six bovine, and 12 porcine samples respectively, and from pooled faecal matter collected from 16 poultry flock samples. All isolates harboured vanA. Three different types of Tn1546-like elements carrying the vanA operon were identified. Conjugal transfer of vanA to human Enterococcus faecalis strain JH2-2 was observed for porcine isolates only. Resistance to tetracycline and erythromycin was frequent among the isolates. Our data show that VRE harbouring vanA are present in healthy food-producing animals. The vanA gene from porcine isolates was transferable to other enterococci and these isolates might play a role in the dissemination of VRE in the food production chain.
Highlights
Antimicrobial resistance has become a permanent aspect of human medicine with vancomycin-resistant enterococci (VRE) gaining importance as nosocomial pathogens worldwide [1]
A multiplex PCR targeting vancomycin resistance genes revealed the presence of vanA in all isolates
The present study demonstrates the occurrence of vanA-type E. faecalis, E. faecium, and E. durans among Swiss cattle, pigs, and poultry flocks 20 years after the ban on avoparcin use
Summary
Antimicrobial resistance has become a permanent aspect of human medicine with vancomycin-resistant enterococci (VRE) gaining importance as nosocomial pathogens worldwide [1]. For European countries, the population-weighted mean percentage of resistance to vancomycin in invasive VREfm increased from 10.5% in 2015 to 17.3% in 2018 [3]. Nosocomial VREfm may arise through independent events of introduction and subsequent dissemination within hospitals, but are thought to generate within patients under antimicrobial therapy, most probably by the acquisition of resistance genes by means of horizontal gene transfer (HGT) [4,5,6,7]. Tn1546-type transposons play a key role in the acquisition and dissemination of vancomycin resistance among enterococci [9,10]. Tn1546 transposons vary structurally, because of point mutations, deletions, or the presence of insertion sequence (IS)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
