The prevalence, serotyping and antimicrobial resistance analysis of Salmonella spp. isolated from the whole chicken production chain in China from 2003 to 2023

ObjectiveThis study aimed to analyze the epidemiological characteristics of Salmonella spp. in the whole chicken production chain in China from 2003 to 2023， in order to understand their prevalence， serotypes and antimicrobial resistance profiles.MethodsThrough searching the databases of CNKI， PubMed， and Web of science， 192 publications involving Salmonella associated with the chicken production chain in China and published from 2003 to 2023 were retrieved， and from them the data were grouped and statistically analyzed by SPSS， R and Excel. The data was divided into four time periods： T1 （2003—2007）， T2 （2008—2012）， T3 （2013—2017）， and T4 （2018—2023）. Contemporary reported data on Salmonella contamination， serotypes and antimicrobial resistance from the European Union and the United States were analyzed for comparison.ResultsBased on literature review， the prevalence of Salmonella in the whole chicken production chain in China from 2003 to 2023 was 17.6%， and the retail （33.7%） and slaughtering （21.3%） stages were higher than the hatching （14.9%） and breeding stages （12.7%）. The positive rate of Salmonella in the slaughtering and retail stages was significantly higher than that in the European Union and the United States （P<0.01）. The dominant serotypes of Salmonella in chicken production chain in China were S. Enteritidis （34.8%）， S. Pullorum （12.0%）， S. Indiana （9.2%）， S. Typhimurium and S. Typhimurium monophasic variant （5.2%）， S. Kentucky （3.7%）. There was a fluctuation in the serotype proportion of Salmonella from chickens at different time period. The S. Kentucky increased in the T2-T4 time period， while the S. Indiana and S. Enteritidis decreased. With S. Enteritidis， S. Typhimurium and S. Typhimurium monophasic variant being the dominant serotypes among China， the European Union and the United States， some serotypes had regional differences. Analysis of Salmonella resistance to 11 antimicrobial drugs showed that the overall resistance rate of Salmonella in China was above 90% during 2003—2023， and the resistance rate in the T4 time period was higher than that in the other three time periods. The multidrug resistance rate showed an increasing trend over time periods.S. Pullorum demonstrated the highest resistance rate （100.0%） to nalidixic acid， while S. Indiana showed the highest resistance to ampicillin （90.0%） and tetracycline （75.7%）. In China， the European Union， and the United States， resistance rates for both tetracycline and ampicillin ranked among the highest. However， the overall resistance level in China was higher than that in the European Union and the United States.ConclusionLiterature data analysis showed that the contamination and drug resistance rate of Salmonella from the whole chicken production chain in China were relatively high， and it is necessary to strengthen the scientific guidance and supervision on chicken production in China.