Contamination Status and Drug Resistance of Salmonella in Livestock and Poultry Meat in Some Areas of Yunnan Province

Purpose To investigate the contamination and drug resistance of Salmonella in fresh livestock and poultry meat in some areas of Yunnan Province.

Methods A total of 164 samples of fresh livestock and poultry meat were collected. Salmonella was isolated and cultured, and identified by matrix assisted laser desorption ionization time-of-flight mass spectrometry. Salmonella serotypes were analyzed by slide agglutination, and molecular typing and cluster analysis were performed by pulsed field gel electrophoresis (PFGE). The antibiotic susceptibility of Salmonella to 14 kinds of antibiotics was carried out by using the detection plate (microbroth dilution method).

Results A total of 19 Salmonella strains were detected in 12 of 164 samples, with a total detection rate of 7.32%. Serotyping revealed five serogroups, among them, the highest number of serotypes in group B (ten strains, 52.6%). Major serotypes included S. typhimurium (five strains), S. saintpaul (three strains), S. paratyphia (two strains) and S. anatum (two strains). PFGE classification had produced 14 different PFGE patterns among 15 strains of Salmonella, indicating a small number of Salmonella in livestock and poultry meat were localized, and there was a regional cross contamination. Out of 19 strains of Salmonella, 17 strains were antibiotic resistant, with a multidrug resistance rate of 68.42%.

Conclusion The detection rate of Salmonella in livestock and poultry meat is high, it presents multiple serotypes, cross-contamination exists, and the drug resistance is serious. It is necessary to strengthen the hygienic management of livestock and poultry meat products and the management of antibiotic use.