Zhang Yunyi, Dong Shilei, Chen Honghu, Chen Jiancai, Zhang Junyan, Zhang Zhen, Yang Yong, Xu Ziyan, Zhan Li, Mei Lingling
Department of Microbiology, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China.
Department of Clinical Laboratory, Zhejiang Hospital, Hangzhou, China.
Front Microbiol. 2019 Jul 25;10:1710. doi: 10.3389/fmicb.2019.01710. eCollection 2019.
is an important foodborne pathogen causing public concern. A total of 3354 retail foods in bulk were sampled and screened for . Seventy-three (2.2%) samples including 21 ready-to-eat (RTE) foods and 52 raw foods were confirmed positive for . Sushi and salmon sashimi occupied the top two slots in RTE foods with relatively high presence rate of 12.9 and 6.9%, respectively. Meanwhile, was found to be distributed unequally in raw foods; the presence rates in raw meat (3.5%) and poultry (3.8%) were significantly higher than that in raw seafood (1.3%). Notably, was not detected in raw freshwater food. The . isolates belonged to four serotypes, 1/2a, 1/2b, 1/2c, and 4b, with the most prevalent serotype being 1/2a (47.9%). Eighteen sequence types (STs) and eighteen virulence types (VTs) containing four newly assigned VTs (VT180, VT181, VT182, and VT183) were determined via multilocus sequence typing (MLST) and multi-virulence-locus sequence typing (MVLST). Among the 73 isolates, 23 (31.5%) belonged to epidemic clones (ECs) including ECI, ECIV, ECV, ECVI, ECVIII and ECXI among which ECV was predominant. Antibiotic susceptibility tests revealed a high resistance rate (11.0%) to tetracycline. Moreover, we identified the distribution patterns of virulence genes of four pathogenicity islands (LIPI) in isolates. , , , , , genes in LIPI-1 and , , , genes in LIPI-2 were detected in approximately all isolates. The distribution of both LIPI-3 genes and LIPI-4 genes exhibited association with lineage and ST. LIPI-4 genes were present exclusively in ST87 isolates. Relatedness analysis revealed the absence of distinct association between STs, ECs, LIPI-3 and LIPI-4 distribution and specific food groups. This study provided fundamental data for Chinese food safety authorities to grasp the contamination status of in foods, assess the potential risk of this pathogen and further address the safety issue of retail foods in bulk in China.
是一种引起公众关注的重要食源性病原体。共采集并筛查了3354份散装零售食品中的 。73份（2.2%）样本被确认为阳性，其中包括21份即食（RTE）食品和52份生食。寿司和三文鱼刺身在即食食品中占前两位，检出率相对较高，分别为12.9%和6.9%。同时，发现 在生食中分布不均；生肉（3.5%）和家禽（3.8%）中的检出率显著高于生海鲜（1.3%）。值得注意的是，在生鲜淡水食品中未检测到 。这些 分离株属于四种血清型，1/2a、1/2b、1/2c和4b，最常见的血清型是1/2a（47.9%）。通过多位点序列分型（MLST）和多毒力位点序列分型（MVLST）确定了18种序列类型（STs）和18种毒力类型（VTs），其中包括四种新指定的VTs（VT180、VT181、VT182和VT183）。在73株 分离株中，23株（31.5%）属于流行克隆（ECs），包括ECI、ECIV、ECV、ECVI、ECVIII和ECXI，其中ECV占主导。抗生素敏感性试验显示对四环素的耐药率较高（11.0%）。此外，我们确定了 分离株中四个 致病岛（LIPI）的毒力基因分布模式。LIPI-1中的 、、、、、 基因以及LIPI-2中的 、、、 基因在几乎所有 分离株中均被检测到。LIPI-3基因和LIPI-4基因的分布均与谱系和ST相关。LIPI-4基因仅存在于ST87分离株中。相关性分析表明，STs、ECs、LIPI-3和LIPI-4分布与特定食品组之间不存在明显关联。本研究为中国食品安全当局掌握食品中 的污染状况、评估该病原体的潜在风险以及进一步解决中国散装零售食品的安全问题提供了基础数据。
