Influence of market type and time of purchase on bacterial counts and Salmonella and Listeria prevalence in chicken in Vietnam

Authors: ENGLISHBEY, APRIL - Texas Tech University; VU, P - Ho Chi Minh City University Of Technology; THUC, YEN - Ho Chi Minh City University Of Technology; SUKUMARAN, ANURAJ - Ho Chi Minh City University Of Technology; LE, MAN - Ho Chi Minh City University Of Technology; NGUYEN, DZUNG - Ho Chi Minh City University Of Technology; Broadway, Paul; GUILLEN, LACEY - Tyson Foods; BRASHEARS, MINDY - Texas Tech University; DONALDSON, JANET - University Of Southern Mississippi; SCHILLING, MARK - Mississippi State University; RUDE, BRIAN - Mississippi State University; CRENSHAW, MARK - Mississippi State University; DINH, THU - Mississippi State University

Submitted to: Meat and Muscle Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/25/2021
Publication Date: 3/16/2022
Citation: Englishbey, A.K., Vu, P.T., Thuc, Y., Sukumaran, A.T., Le, M., Nguyen, D., Broadway, P.R., Guillen, L.M., Brashears, M.M., Donaldson, J.R., Schilling, M.W., Rude, B.J., Crenshaw, M.A., Dinh, T. 2022. Influence of market type and time of purchase on bacterial counts and Salmonella and Listeria prevalence in chicken in Vietnam. Meat and Muscle Biology. 6(1). Article 12933. https://doi.org/10.22175/mmb.12933.
DOI: https://doi.org/10.22175/mmb.12933

Interpretive Summary: This study was designed to evaluate Salmonella and Listeria in chicken in Vietnam. Since marketing of meat products is different than that in the United States, samples were collected from whole chicken carcasses in supermakets, indoor markets, and outdoor markets. Additionally samples were taken from each location in the morning and again in the afternoon to evaluate how refridgeration, or the lack thereof influenced pathogen growth. Salmonella contamination rates averaged over 30%, and Listeria contamination rates were greater than 50%. Interestingly, there was no difference in bacterial counts between supermarkets and outdoor markets, however contamination rates were decreased in indoor markets. While overall contamination rates were reduced in indoor markets, much variability exists between similar markets with respect to hygiene and food safety practices. Importantly, however, is the fact that contamination of chicken carcasses available for retail purchase could pose a food safety risk for consumers in Vietnam.

Technical Abstract: The Objective of the current study was to determine the influence of market type and sampling time on Salmonella and Listeria prevalence and bacterial population levels of 180 whole chicken carcasses collected in 6 supermarkets (SM), 6 indoor markets (IM), and 6 open markets (OM) at the opening (TO) and 4 h after the opening (T4) in Vietnam. Salmonella and Listeria prevalence were greater than 30.4 and 56.6%, respectively. Chicken carcasses had more than 10.1, 7.5, and 9.4 log CFU/g of aerobic bacteria, Escherichia coli (E.coli), and coliforms, respectively. Sampling did not influence counts of aerobic bacteria, E.coli, and coliforms, nor did it affect Salmonella and Listeria prevalance (P=0.113). Both E.coli and coliform counts were greater in IM than in SM (P=0.002 and 0.006, respectively)> However, only E.coli counts differed between SM (7.7 log CFU/g) and OM (8.3 log CFU/g; P=0.024). Whole birds in IM had greater Salmonella prevalence than birds from both SM and OM by 28.4 and 23.0% (P=0.006 and 0.022, respectively). Listera prevalence was significantly less in SM, at 56.6%, than in IM and OM (78.6 and 73.2%, P=0.024 and 0.089, respectively). There was no market type by sampling time interaction for all microbiological measurements (P>0.118). Market characteristics such as display, refrigeration, hot water, and hygienic conditions varied greatly among vendors in SM, IM, and OM. These results highlighted high levels of bacterial loads and incidence in whole chicken in retail establishments in Vietnam, which poses potential food safety and public health risks.