Article Text

Prevalence of antimicrobial resistance in faecal enterococci from vet-visiting pets and assessment of risk factors
  1. L. Leite-Martins, DVM, PhD1,2,
  2. M. I. Mahú, MSc2,3,
  3. A. L. Costa2,
  4. L. J. Bessa, PhD2,4,
  5. P. Vaz-Pires, DVM, PhD2,
  6. L. Loureiro, DVM, PhD5,
  7. J. Niza-Ribeiro, DVM PhD6,
  8. A. J. F. de Matos, DVM, PhD1,7 and
  9. P. Martins da Costa, DVM, PhD2,4
  1. 1Department of Veterinary Clinics – UPVet, Abel Salazar Institute for the Biomedical Sciences (ICBAS), University of Porto, Porto, Portugal
  2. 2Department of Aquatic Production, ICBAS, University of Porto, Porto, Portugal
  3. 3Gulbenkian Science Institute, Lisbon, Portugal
  4. 4Interdisciplinary Centre for Marine and Environmental Research (CIIMAR), University of Porto, Porto, Portugal
  5. 5Department of Global Community Health and Behavioral Sciences, Tulane School of Public Health and Tropical Medicine, New Orleans, USA
  6. 6Department of Population Studies, ICBAS, and Institute of Public Health (ISPUP), University of Porto, Porto, Portugal
  7. 7Animal Science and Study Centre/Food and Agrarian Sciences and Technologies Institute (CECA/ICETA), University of Porto, Porto, Portugal
  1. E-mail for correspondence: lmartins{at}


The objective of this study was to determine the prevalence of antimicrobial resistance (AMR) exhibited by enterococci isolated from faeces of pets and its underlying risk factors. From September 2009 to May 2012, rectal swabs were collected from 74 dogs and 17 cats, selected from the population of animals visiting the Veterinary Hospital of University of Porto, UPVet, through a systematic random procedure. Animal owners answered a questionnaire about the risk factors that could influence the presence of AMR in faecal enterococci. Enterococci isolation, identification and antimicrobial (AM) susceptibility testing were performed. Data analyses of multilevel, univariable and multivariable generalised linear mixed models were conducted. From all enterococci isolated (n=315), 61 per cent were considered multidrug-resistant, whereas only 9.2 per cent were susceptible to all AMs tested. Highest resistance was found to tetracycline (67.0 per cent), rifampicin (60.3 per cent), azithromycin (58.4 per cent), quinupristin/dalfopristin (54.0 per cent) and erythromycin (53.0 per cent). Previous fluoroquinolone treatments and coprophagic habits were the features more consistently associated with the presence of AMR for three (chloramphenicol, ciprofloxacin and azithromycin) and seven (tetracycline, rifampicin, gentamicin, chloramphenicol, ciprofloxacin, erythromycin and azithromycin), respectively, out of nine AMs assessed. Evaluating risk factors that determine the presence of drug-resistant bacteria in pets, a possible source of resistance determinants to human beings, is crucial for the selection of appropriate treatment guidelines by veterinary practitioners.

  • Bacteriology
  • Epidemiology
  • Pets
  • Resistance
  • Antimicrobials

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.