Raw pet food as a risk factor for shedding of extended-spectrum beta-lactamase-producing Enterobacteriaceae in household cats

Valérie O Baede; Els M Broens; Mirlin P Spaninks; Arjen J Timmerman; Haitske Graveland; Jaap A Wagenaar; Birgitta Duim; Joost Hordijk

doi:10.1371/journal.pone.0187239

Raw pet food as a risk factor for shedding of extended-spectrum beta-lactamase-producing Enterobacteriaceae in household cats

PLoS One. 2017 Nov 2;12(11):e0187239. doi: 10.1371/journal.pone.0187239. eCollection 2017.

Authors

Valérie O Baede¹, Els M Broens¹, Mirlin P Spaninks¹, Arjen J Timmerman¹, Haitske Graveland¹, Jaap A Wagenaar^{1

2}, Birgitta Duim¹, Joost Hordijk¹

Affiliations

¹ Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands.
² Wageningen Bioveterinary Research, Lelystad, the Netherlands.

Abstract

Background: Close contact between pets and owners provides the opportunity for transmission of antimicrobial resistant organisms like extended-spectrum beta-lactamase (ESBL)/AmpC beta-lactamase (AmpC)-producing Enterobacteriaceae, posing a risk to public health.

Objectives: To investigate whether raw feed is a risk factor for household cats to shed ESBL-producing Enterobacteriaceae, a cohort study was designed. Additionally, raw and non-raw commercial pet food products were screened for the presence of ESBL-producing Enterobacteriaceae.

Methods: Weekly fecal samples of 17 cats in the control group and 19 cats in the exposed group were collected for three weeks and analyzed for the presence of ESBL-producing Enterobacteriaceae. Questionnaires were obtained to determine additional risk factors. Fecal samples were cultured on MacConkey agar supplemented with 1 mg/L cefotaxime. PCR and sequence analysis was used for screening for ESBL genes in suspected isolates. Pet food samples were cultured in LB broth supplemented with 1 mg/L cefotaxime and processed as described above.

Results: In the cohort study, ESBL-producing bacteria were isolated from 3 of 51 (5.9%) samples in the control group compared to 37 of 57 (89.5%) samples in the exposed group. A significant association was found between ESBL shedding and feeding raw pet food products (OR = 31.5). No other risk factors were identified in this study. ESBL-producing Enterobacteriaceae were isolated from 14 of 18 (77.8%) raw pet food products and 0 of 35 non-raw pet food products.

Conclusions: This study shows a strong association between shedding of ESBL-producing bacteria in household cats and feeding raw pet food. Raw pet food was often contaminated with ESBL-producing Enterobacteriaceae.

MeSH terms

Animal Feed*
Animals
Cats
Enterobacteriaceae Infections / physiopathology*
Pets*
Risk Factors

Grants and funding

This project was funded by the Dutch Ministry of Economic Affairs and the animal production sectors, as part of the ESBL attribution project (ESBLAT), grant number TKI-AF-12067. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.