Analysis of pathogenic bacteria contamination in the commercially available raw livestock meat in the Chinese mainland in 2021

Abstract

ObjectiveTo investigate the contamination characteristics of common foodborne pathogens in raw livestock meat in the Chinese mainland market.MethodsIn 2021， a total of 4 734 samples of raw livestock meat were collected from 31 provinces （autonomous regions/municipalities） and Xinjiang Construction Corps， and qualitative tests were conducted for Salmonella， Listeria monocytogenes （L. monocytogenes）， diarrheagenic Escherichia coli （DEC） and Yersinia enterocolitica according to the national standard method of food safety.ResultsSalmonella had the highest detection rate with 12.10% （573/4 734）， followed by L. monocytogenes， which is 9.51% （450/4 734）， the detection ratio of DEC and Yersinia enterocolitica was 6.36% （301/4 734） and 2.18% （103/4 734） respectively. The detection rates of Salmonella and DEC in pork were 19.86% and 8.37%， respectively， higher than those of beef and mutton （about 4%）. There were differences in the detection of pathogenic bacteria in raw livestock meat under different preservation conditions. The detection rates of L. monocytogenes and Yersinia enterocolitis in chilled and frozen meat were higher than those in fresh meat. Salmonella and DEC had the highest detection rates in fresh meat. The positive rates of Salmonella and DEC in fresh meat in the second and third quarters were higher than those in the first and fourth quarters. The detection rates of Salmonella and DEC in bulk raw livestock meat were higher than those in pre-packaged products. The detection rates of Salmonella and L. monocytogenes were higher in the south China than those in the north China. The detection rate of DEC in the north was higher than that in the south. A total of 573 strains of Salmonella were isolated from raw livestock meat. The top 5 serotypes and their proportions in descending order were S. typhimurium 19.90%， S. derby 12.57%， S. london 12.22%， S. rissen 10.12% and S. enteritidis 2.97%.ConclusionThe detection rate of pathogenic bacteria in raw livestock meat is high， especially the contamination of L. monocytogenes in frozen and chilled livestock meat and Salmonella in fresh livestock meat in the second and third quarters are serious， which should be taken as the focus of monitoring in the future. Enterprises and consumers should pay attention to preventing the possible risk of disease caused by incomplete heating and cross-contamination of raw and cooked animals.

Keywords

• raw livestock meat
• foodborne pathogens
• listeria monocytogenes
• salmonella
• diarrheagenic escherichia coli
• yersinia enterocolitis
• contamination