Antimicrobial residues and resistance in non-typhoidal Salmonella from meat sold at markets in Vietnam
A recent survey conducted by our research team found considerably higher levels of contamination with antimicrobial residues in meat cuts sold at wet markets in Vietnam compared with similar meat sourced from supermarkets.
The study was based on a sample of 357 meat samples collected in markets in Dong Thap province and the urban hubs of Hanoi and Ho Chi Minh City between early November 2016 and March 2017. Antimicrobial residues were detected in total of 26 (7.3%) samples (9.5% beef, 4.1% pork and 8.4% chicken meat). Samples from wet-markets showed a higher percentage of residue contamination (9.6%) compared with samples from supermarkets (2.6%). Unsurprisingly sulfonamides, tetracyclines and macrolides, all antimicrobials extensively used in pig and poultry production, were the most frequently detected residues.
Furthermore, 68.4% meat samples purchased from markets in Ho Chi Minh City were contaminated with non-tyhphoidal Salmonella, one of the major causes of gastroenteritis (diarrhoea) in Vietnam and elsewhere. We also report high levels of antimicrobial resistance among Salmonella isolates against quinolones (52.2%) and penicillin (49.6%) antimicrobials, both considered of critical importance for human medicine.
This study was carried out in collaboration with the Sub-Department of Animal Health and Production of Dong Thap and the National Institute of Veterinary Research in Hanoi. Antimicrobial residues in animal food products are of concern, since they may cause several adverse health effects to consumers, such as allergic/toxic reactions, disruption of intestinal flora, chronic toxic effects occurring with prolonged exposure to low levels of residues and the potential emergence of resistance in host flora or subsequent spread.
We are also currently assessing the presence of antimicrobial residues in chickens that are enrolled in the ViParc project. Our results will contribute to assess the human hazards associated with antimicrobial usage on farms, as well as one of the endpoints that will be measured as part of the planned intervention.