Prevalence and risk factors for carriage of antimicrobial-resistant Escherichia coli on household and small-scale chicken farms in the Mekong Delta of Vietnam
- Trung Nguyen Vinh1,2,3,*,
- Juan J. Carrique-Mas3,4,
- Ngo Thi Hoa3,4,
- Ho Huynh Mai5,
- Ha Thanh Tuyen3,
- James I. Campbell3,4,
- Nguyen Thi Nhung3,
- Hoang Ngoc Nhung3,
- Pham Van Minh3,
- Jaap A. Wagenaar6,7,
- Anita Hardon8,
- Thai Quoc Hieu5 and
- Constance Schultsz1,2,3
- 1Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- 2Department of Global Health-Amsterdam Institute for Global Health and Development, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- 3Oxford University Clinical Research Unit, Centre for Tropical Medicine, Ho Chi Minh City, Vietnam
- 4Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- 5Sub-Department of Animal Health, My Tho, Tien Giang, Vietnam
- 6Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
- 7Central Veterinary Institute of Wageningen UR, Lelystad, The Netherlands
- 8Center for Social Science and Global Health, University of Amsterdam, Amsterdam, The Netherlands
- ↵*Corresponding author. Tel: +84-8-39241761; Fax: +84-8-39238904; E-mail: trungnv{at}oucru.org
- Received October 8, 2014.
- Revision requested December 17, 2014.
- Revision received January 27, 2015.
- Accepted February 6, 2015.
Abstract
Objectives To describe the prevalence of antimicrobial resistance among commensal Escherichia coli isolates on household and small-scale chicken farms, common in southern Vietnam, and to investigate the association of antimicrobial resistance with farming practices and antimicrobial usage.
Methods We collected data on farming and antimicrobial usage from 208 chicken farms. E. coli was isolated from boot swab samples using MacConkey agar (MA) and MA with ceftazidime, nalidixic acid or gentamicin. Isolates were tested for their susceptibility to 11 antimicrobials and for ESBL production. Risk factor analyses were carried out, using logistic regression, at both the bacterial population and farm levels.
Results E. coli resistant to gentamicin, ciprofloxacin and third-generation cephalosporins was detected on 201 (96.6%), 191 (91.8%) and 77 (37.0%) of the farms, respectively. Of the 895 E. coli isolates, resistance to gentamicin, ciprofloxacin and third-generation cephalosporins was detected in 178 (19.9%), 291 (32.5%) and 29 (3.2%) of the isolates, respectively. Ciprofloxacin resistance was significantly associated with quinolone usage (OR = 2.26) and tetracycline usage (OR = 1.70). ESBL-producing E. coli were associated with farms containing fish ponds (OR = 4.82).
Conclusions Household and small farms showed frequent antimicrobial usage associated with a high prevalence of resistance to the most commonly used antimicrobials. Given the weak biocontainment, the high prevalence of resistant E. coli could represent a risk to the environment and to humans.
Key words
- © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
