Abstract：
Listeria monocytogenes is a critical foodborne pathogen that causes severe invasive and noninvasive diseases and is associated with high mortality. Information on the prevalence of L. monocytogenes infections in Taiwan is very limited. This study aimed to analyze the molecular epidemiological surveillance and virulence gene distribution of 176 human clinical L. monocytogenes isolates collected between 2009 and 2019 in northern Taiwan. Our results showed that the isolates belonged to 4 serogroups (IIa, IIb, IVb, and IIc), with most isolates in serogroups IIa (81/176, 46%) and IIb (71/176, 40.3%). Multilocus sequence typing analysis revealed 18 sequence types (STs) and 13 clonal complexes (CCs). Eighty-four percent of all isolates belonged to six STs: CC87-ST87 (40/176, 22.7%), CC19-ST378 (36/176, 19.9%), CC155-ST155 (28/176, 15.5%), CC1-ST710 (16/176, 8.8%), CC5-ST5 (16/176, 8.8%), and CC101-ST101 (11/176, 6.1%). Furthermore, our analysis showed the distributions of four Listeria pathogenicity islands (LIPI) among all isolates. LIPI-1 and LIPI-2 existed in all isolates, whereas LIPI-3 and LIPI-4 only existed in specific STs and CCs. LIPI-3 existed in the STs, CC1-ST710, CC3-ST3, CC288-ST295, and CC191-ST1458, whereas LIPI-4 could be found in the STs, CC87-ST87 and CC87-ST1459. Strains containing LIPI-3 and LIPI-4 are potentially hypervirulent; thus, 68/176 isolates (39.1%) collected in this study were potentially hypervirulent. Since L. monocytogenes infections are considered highly correlated with diet, molecular epidemiological surveillance of Listeria in food is important; continued surveillance will provide critical information to prevent foodborne diseases.
摘要：
单核细胞增生李斯特菌是一种重要的食源性病原体，可引起严重的侵袭性和非侵袭性疾病，并伴有高死亡率。有关台湾单核细胞增多性李斯特菌感染患病率的信息非常有限。本研究旨在分析2009年至2019年在台湾北部收集的176株人类临床单核细胞增生李斯特菌的分子流行病学监测和毒力基因分布。我们的结果表明，这些分离株属于4个血清群(IIa，IIb,IVb,andIIc),大多数分离株在血清群IIa(81/176，46%)和IIb(71/176，40.3%)中。多位点序列分型分析揭示了18种序列类型（STs）和13种克隆复合物（CC）。所有分离株中的84％属于六个ST：CC87-ST87（40/176，22.7％），CC19-ST378(36/176,19.9%),CC155-ST155(28/176,15.5%),CC1-ST710（16/176，8.8%），CC5-ST5（16/176，8.8%），和CC101-ST101（11/176，6.1%）。此外，我们的分析显示了四个李斯特菌致病性岛（LIPI）在所有分离物中的分布。LIPI-1和LIPI-2存在于所有分离株中,而LIPI-3和LIPI-4仅存在于特定的ST和CC中。LIPI-3存在于ST中，CC1-ST710，CC3-ST3，CC288-ST295和CC191-ST1458，而LIPI-4可以在ST中找到，CC87-ST87和CC87-ST1459。含有LIPI-3和LIPI-4的菌株具有潜在的高毒力；因此，在这项研究中收集的68/176分离株（39.1％）具有潜在的高毒力。由于单核细胞增生李斯特菌感染被认为与饮食高度相关，食品中李斯特菌的分子流行病学监测很重要；持续的监测将提供预防食源性疾病的关键信息。
