Wu Shi, Wu Qingping, Zhang Jumei, Chen Moutong, Yan Ze An, Hu Huijuan
School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, PR China; Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, PR China.
Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, PR China.
PLoS One. 2015 Aug 28;10(8):e0136682. doi: 10.1371/journal.pone.0136682. eCollection 2015.
The prevalence and levels of Listeria monocytogenes in retail raw foods covering most provincial capitals in China were studied with testing of 1036 samples of vegetables, edible mushrooms, raw meat, aquatic products and quick-frozen products from September 2012 to January 2014. The total prevalence of Listeria monocytogenes was 20.0% (207/1036), and the most probable number (MPN) values of 65.7% of the positive samples ranged from 0.3 to 110 MPN/g. Geographical differences were observed in this survey, and the results of both qualitative and quantitative methods indicated that the levels in the samples from North China were higher than those in the samples from South China. A total of 248 isolates were analyzed, of which approximately half belonged to molecular serogroup 1/2a-3a (45.2%), followed by 1/2b-3b-7 (30.6%), 1/2c-3c (16.1%), 4b-4d-4e (5.2%) and 4a-4c (2.8%). Most of the isolates carried hly (100%), inlB (98.8%), inlA (99.6%), inlC (98.0%) and inlJ (99.2%), and 44.8% of the isolates were llsX-positive. Seventeen epidemic clones (ECs) were detected, with 7 strains belonging to ECI (2.8%) and 10 belonging to ECIII (4.03%). Resistance to clindamycin (46.8%) was commonly observed, and 59 strains (23.8%) were susceptible to all 14 tested antibiotics, whereas 84 (33.9%) showed an intermediate level of resistance or were resistant to two or more antibiotics, including 7 multi-resistant strains that exhibited resistance to more than 10 antibiotics. The data obtained in the present study provides useful information for assessment of the possible risk posed to Chinese consumers, and this information will have a significant public health impact in China. Furthermore, the presence of virulence markers, epidemic clones, as well as the antibiotic resistance amongst the isolates strongly implies that many of these strains might be capable of causing listeriosis, and more accurate treatment of human listeriosis with effective antibiotics should be considered. This research represents a more full-scale and systematical investigation of the prevalence of L. monocytogenes in retail raw foods in China, and it provides baseline information for Chinese regulatory authorities that will aid in the formulation of a regulatory framework for controlling L. monocytogenes with the aim of improving the microbiological safety of raw foods.
2012年9月至2014年1月，对覆盖中国大部分省会城市的零售生鲜食品中单核细胞增生李斯特菌的流行情况和水平进行了研究，共检测了1036份蔬菜、食用菌、生肉、水产品和速冻产品样本。单核细胞增生李斯特菌的总流行率为20.0%（207/1036），65.7%的阳性样本的最大可能数（MPN）值在0.3至110 MPN/g之间。本次调查观察到地理差异，定性和定量方法的结果均表明，华北地区样本中的水平高于华南地区样本。共分析了248株分离株，其中约一半属于分子血清群1/2a - 3a（45.2%），其次是1/2b - 3b - 7（30.6%）、1/2c - 3c（16.1%）、4b - 4d - 4e（5.2%）和4a - 4c（2.8%）。大多数分离株携带hly（100%）、inlB（98.8%）、inlA（99.6%）、inlC（98.0%）和inlJ（99.2%），44.8%的分离株llsX呈阳性。检测到17个流行克隆（ECs），其中7株属于ECI（2.8%），10株属于ECIII（4.03%）。常见对克林霉素耐药（46.8%），59株（23.8%）对所有14种测试抗生素敏感，而84株（33.9%）表现出中度耐药或对两种或更多抗生素耐药，包括7株多重耐药菌株，对10种以上抗生素耐药。本研究获得的数据为评估对中国消费者可能造成的风险提供了有用信息，这些信息将对中国公共卫生产生重大影响。此外，分离株中存在毒力标记、流行克隆以及抗生素耐药性强烈表明，这些菌株中的许多可能能够引起李斯特菌病，应考虑使用有效的抗生素对人类李斯特菌病进行更准确的治疗。本研究是对中国零售生鲜食品中单核细胞增生李斯特菌流行情况更全面、系统的调查，为中国监管机构提供了基线信息，有助于制定控制单核细胞增生李斯特菌的监管框架，以提高生鲜食品的微生物安全性。
