【摘要】 目的 分析成都市金针菇产销环节中单增李斯特菌的污染状况。方法 采集成都市两家金针菇厂的金针菇(30份)、培养基(14份)、环境(25份)、工具设备(64份)、操作人员(30份)和其他样本(17份),共计180份，依据《2024年国家食品污染和有害因素风险监测工作手册》分离鉴定单增李斯特菌，并对菌株进行全基因组测序(WGS),预测血清型，分析其谱系、序列型(ST)、克隆群(CC)、耐药基因与毒力基因，根据核心基因组多位点序列分型(cgMLST)遗传特性确定菌株同源性。结果 180份样本中检出单增李斯特菌69株，总检出率为38.33%;菌株分属2个谱系(Ⅰ和Ⅱ),以谱系Ⅱ为主(97.10%,67/69);分属3种血清型，其中1/2a, 3a为优势血清型(94.20%,65/69);分属7个CC型，其中CC8(52.17%,36/69)和CC155(30.43%,21/69)为优势CC型。分属8个ST型，其中ST8(52.17%,36/69)和ST155(30.43%,21/69)为优势ST型。菌株均仅携带耐药基因fosX。69株菌均携带毒力岛1(LIPI-1),6个毒力基因(prfA、plcA、hly、mpl、actA和plcB)均为阳性；69株菌均携带毒力岛2(LIPI-2),9个毒力基因中inlA、inlB、inlC和inlJ均为阳性，inlE、inlG和inlH均为阴性，inlF和inlK的携带率均为97.10%(67/69)。cgMLST聚类结果显示存在同源的菌株。结论 成都市金针菇生产过程与销售环节中单增李斯特菌均存在污染状况，且存在交叉污染的可能。菌株耐药情况暂不严重，但所携带的毒力基因较多，有可能获得耐药基因并对人致病。更多还原

【Abstract】 Objective To analyze the contamination status of Listeria monocytogenes in the production and distribution stages of enoki mushrooms in Chengdu. Methods A total of 180 samples were collected from two major enoki mushroom manufacturers in Chengdu, including enoki mushrooms(30 samples), culture media(14 samples), environmental samples(25 samples), tools and equipment(64 samples), operators(30 samples), and other samples(17 samples). L.monocytogenes was isolated and identified according to the 2024 National Manual for Monitoring Food Contaminants and Harmful Factors. Whole-genome sequencing(WGS) was conducted on the isolates to predict serotypes and analyze lineages, sequence types(ST), clonal complexes(CC), antimicrobial resistance genes, and virulence genes. Homology among strains was determined based on core genome multilocus sequence typing(cgMLST) genetic characteristics. Results A total of 69 L.monocytogenes strains were detected from 180 samples, with an overall detection rate of 38.33%. The strains belonged to two lineages(I and II), with lineage II being predominant(97.10%, 67/69). Three serotypes were identified, among which serotype 1/2a, 3a was dominant(94.20%, 65/69). Seven CC types were detected, with CC8(52.17%, 36/69) and CC155(30.43%, 21/69) being dominant. Eight ST types were identified, among which ST8(52.17%, 36/69) and ST155(30.43%, 21/69) were the predominant types. All strains carried only the antimicrobial resistance gene fosX. All 69 strains carried virulence island 1(LIPI-1), and six virulence genes(prfA, plcA, hly, mpl, actA, and plcB) were all positive. All 69 strains also carried virulence island 2(LIPI-2); among the nine virulence genes, inlA, inlB, inlC, and inlJ were positive in all strains; inlE, inlG, and inlH were all negative; and the carriage rates of inlF and inlK were both 97.10%(67/69). CgMLST clustering analysis revealed the presence of homologous strains. Conclusion L.monocytogenes contamination is present in both the production and distribution stages of enoki mushrooms in Chengdu, with a potential for cross-contamination. Although current antimicrobial resistance is not severe, the strains harbor numerous virulence genes, suggesting potential for acquiring resistance genes and posing a threat to human health.更多还原