【摘要】 目的 分析广西即食食品中单核细胞增生李斯特菌(以下简称单增李斯特菌)的耐药性、分子特征和毒力特征，更好地了解即食食品中单增李斯特菌的遗传特点、耐药情况及其潜在的健康风险。方法 采用肉汤稀释法对158株即食食品中单增李斯特进行药敏测定，同时对其进行全基因组测序(WGS),分析其序列ST型、血清群、血清型、CC型、谱系、耐药基因及毒力基因。结果 2011—2020年广西即食食品中单增李斯特菌以1/2a, 3a血清型为主，优势ST型为ST8/CC8和ST87/CC87。研究菌株均对AMP、PEN、TET、MEM、SXT敏感，4株分离株耐受CIP,2株单增李斯特菌分别耐受ERY和VAN。仅对红霉素耐药的1株分离株携带tet(M)、msr(D)、mef(A)耐药基因。actA、inlF、inlK的携带率分别为79.74%、48.73%、55.69%,其余毒力基因携带率为100%。46.20%(73/158)的菌株携带12个毒力基因，24株高毒力单增李斯特菌产生潜在高致病菌株。结论 广西即食食品中单增李斯特菌存在的获得性耐药基因和高毒力基因对公众健康构成严重风险，应该对即食食品加工和服务环境采取有效的食品安全措施。更多还原

【Abstract】 Objective To comprehensively analyze the occurrence, virulence characteristics, and molecular typing of Listeria monocytogenes(L.monocytogenes) isolated from ready-to-eat(RTE) food in Guangxi. By investigating the genetic attributes, antibiotic resistance and potential health risks of L.monocytogenes, this research contributes to our understanding of this pathogen. Methods We analyzed 158 isolates of L. monocytogenes from RTE foods collected in Guangxi between 2011 and 2020. Whole genome sequencing(WGS) was performed on all isolates and antimicrobial resistance were determined by broth microdilution.The study included the determination of sequence types(STs), serotype, serogroup, lineage, clonal complexes(CC), acquired resistance genes and the presence of L. monocytogenes pathogenicity islands(LIPIs). Results Ready-to-eat meats had the highest detection rate of L.monocytogenes among RTE foods in Guangxi. The predominant serotypes were 1/2a, 3a.ST8/CC8 and ST87/CC87 were the dominant sequence types(STs) in RTE foods.All isolates were found to be susceptible to ampicillin(AMP), penicillin(PEN), tetracycline(TET), meropenem(MEM), and trimethoprim-sulfamethoxazole(SXT). Four isolates were resistant to ciprofloxacin. Two isolates wereresistant to erythromycin and vancomycin respectively. Acquired antimicrobial phenotypes were tet(M), msr(D)and mef(A) of an isolate resistant to erythromycin. Most of the isolates carried actA(79.74%), inlF(48.73%), inlK(55.69%)and all isolates carried other virulence genes.46.20%(73/158)of the isolatesharboured 12 virulence genes.It can be a potential public health risk due to its high harboring rate of 17 or 18 virulence genes. Conclusion Ready-to-eat meats had the highest detection rate of L.monocytogenes among RTE foods in Guangxi.Acquired resistance genes and hypervirulence genes existed in this bacterium from RTE foods origins, and can be a major risk for consumers and public health.It was suggested that effective food safety measures should be implemented in RTE foods processing and service environments.更多还原