Analysis of Transmission of MRSA and ESBL-E among Pigs and Farm Personnel

PLoS One. 2015 Sep 30;10(9):e0138173. doi: 10.1371/journal.pone.0138173. eCollection 2015.

Abstract

Livestock-associated bacteria with resistance to two or more antibiotic drug classes have heightened our awareness for the consequences of antibiotic consumption and spread of resistant bacterial strains in the veterinary field. In this study we assessed the prevalence of concomitant colonization with livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) and enterobacteriaceae expressing extended-spectrum betalactamases (ESBL-E) in farms at the German-Dutch border region. Nasal colonization of pigs with MRSA (113/547 (20.7%)) was less frequent than rectal colonization with ESBL-E (163/540 (30.2%)). On the individual farm level MRSA correlated with ESBL-E recovery. The data further provide information on prevalence at different stages of pig production, including abattoirs, as well as in air samples and humans living and working on the farms. Notably, MRSA was detected in stable air samples of 34 out of 35 pig farms, highlighting air as an important MRSA transmission reservoir. The majority of MRSA isolates, including those from humans, displayed tetracycline resistance and spa types t011 and t034 characteristic for LA-MRSA, demonstrating transmission from pigs to humans. ESBL-E positive air samples were detected on 6 out of 35 farms but no pig-to-human transmission was found. Detection of ESBL-E, e.g. mostly Escherichia coli with CTX-M-type ESBL, was limited to these six farms. Molecular typing revealed transmission of ESBL-E within the pig compartments; however, related strains were also found on unrelated farms. Although our data suggest that acquisition of MRSA and ESBL-E might occur among pigs in the abattoirs, MRSA and ESBL-E were not detected on the carcasses. Altogether, our data define stable air (MRSA), pig compartments (ESBL-E) and abattoir waiting areas (MRSA and ESBL-E) as major hot spots for transmission of MRSA and/or ESBL-E along the pig production chain.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animal Husbandry*
  • Animals
  • Escherichia coli Infections / transmission*
  • Escherichia coli*
  • Female
  • Humans
  • Male
  • Methicillin-Resistant Staphylococcus aureus*
  • Staphylococcal Infections / transmission*
  • Swine / microbiology*
  • Zoonoses / transmission*
  • beta-Lactam Resistance*

Grant support

The project was financed by the FIN-Q NRW research network funded by the European Union and the state of North Rhine Westfalia, Germany. Reference number: 005-NA01-030 (http://giqs.org/projekte/abgeschlossene-projekte/fin-qnrw/). LeanIX GmbH provided support in the form of salaries for author André Christ, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of this author are articulated in the ‘author contributions’ section.