Prevalence, enumeration, and pheno- and genotypic characteristics of Listeria monocyto genes isolated from raw foods in South China
Prevalence, enumeration, and pheno- and genotypic characteristics of Listeria monocyto genes isolated from raw foods in South China
复制标题
华南生食中单核细胞李斯特菌基因的流行率、计数以及表型和基因型特征
DOI：
10.3389/fmicb.2015.01026
复制
发表时间：
2015-09-29
影响因子：
5.2
通讯作者：
Guo, Weipeng
中科院分区：
文献类型：
--
作者：
Chen, Moutong;Wu, Qingping;Guo, Weipeng
单核细胞增生李斯特菌是一种重要的食源性病原体，可导致免疫功能低下的个体，孕妇，老年人和新生儿严重疾病。本研究的目的是：（i）评估流行和污染水平[最可能数（MPN）]的L。从华南地区收集的567种零售生食（水产品，n = 154;生/鲜肉，n = 123;冷冻食品，n = 110;食用菌，n = 108;蔬菜，n = 72）中的单核细胞增生症;（ii）进一步了解这种重要食源性病原体的表型和基因型分布。约22%的样本为L阳性。单核细胞增多症污染水平在0.3 ~ 10 MPN/g的占75.0%，在10 ~ 100 MPN/g的占11.0%，小于100 MPN/g的占14.0%。从177株食源性L.单核细胞增多症分离株以1/2a-3a（42.4%）和1/2b-3b（26.0%）血清型为主。血清群1.1和11.2仅在食用菌中发现，而血清群III在水产品中占优势，提示特定血清群的L.单核细胞增多症可能有不同的生态位。10个（5.6%）L.单核细胞增生分离株表现出多药耐药。遗传相关性分析显示，特定的食物类型，抗生素耐药性，血清群和遗传多样性之间没有明显的关联。本研究首次提供了关于L.中国南方生食中分离的单核细胞增多症。一些多重耐药菌株属于流行病学上重要的血清群（1.1和11.1），这意味着潜在的公共卫生风险。此外，这些研究结果也为我国食品安全相关部门制定相应的标准控制L。防止单核细胞增多症污染，提高生食的微生物安全性。
Listeria monocytogenes is an important foodborne pathogen that can cause serious illness in immunocompromised individuals, pregnant women, the elderly, and newborns. The aim of this study was to: (i) evaluate the prevalence and contamination level [most probable number (MPN)] of L. monocytogenes in 567 retail raw foods (fishery products, n = 154; raw/fresh meat, n = 123; frozen foods, n = 110; edible fungi, n = 108; vegetables, n = 72) collected from South China and (ii) to gain further knowledge on the phenotype and genotype distributions of this important foodborne pathogen. Approximately 22% of the samples were positive for L. monocytogenes. The contamination levels were between 0.3 and 10 MPN/g in 75.0%, between 10 and 100 MPN/g in 11.0% and less than 100 MPN/g in 14.0% of the countable samples. Five serogroups were identified among the 177 foodborne L. monocytogenes isolates, with 1/2a-3a (42.4%) and 1/2b-3b (26.0%) serogroups being the most dominant. Serogroups 1.1 and 11.2 were only found in the edible mushrooms, while serogroup III was dominant in the fishery products, suggesting that specific serogroups of L. monocytogenes may have distinct ecological niches. Ten (5.6%) L. monocytogenes isolates exhibited multidrug resistance. Genetic relatedness analysis revealed the absence of distinct associations between specific food types, antibiotic resistance, serogroups, and genetic diversity. The present study provided the first baseline data on the prevalence, contamination level, and characteristics of L. monocytogenes isolated from raw foods in South China. Some multidrug resistant strains belonged to the epidemiologically important serogroups (1.1 and 11.1), implying a potential public health risk. In addition, these findings also provide basic information for the Chinese food safety associated authorities to draft appropriate standards to control L. monocytogenes contamination and improve microbiological safety of raw foods.