Molecular Epidemiological Characterization of Staphylococcus argenteus Clinical Isolates in Japan: Identification of Three Clones (ST1223, ST2198, and ST2550) and a Novel Staphylocoagulase Genotype XV
Molecular Epidemiological Characterization of Staphylococcus argenteus Clinical Isolates in Japan: Identification of Three Clones (ST1223, ST2198, and ST2550) and a Novel Staphylocoagulase Genotype XV
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DOI：
10.3390/microorganisms7100389
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发表时间：
2019-10-01
期刊：
影响因子：
4.5
通讯作者：
Kobayashi, Nobumichi
中科院分区：
文献类型：
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作者：
Aung, Meiji Soe;Urushibara, Noriko;Kobayashi, Nobumichi
银黄色葡萄球菌是金黄色葡萄球菌复合体(SAC)中的一个新的新物种，在世界范围内得到了越来越多的报道。本研究在日本北部主岛北海道调查了银链球菌在人类临床分离株中的流行情况，以及它们的克隆多样性和毒力因子的遗传特征。从2019年3月开始的四个月期间，从临床标本中回收了24株银黄色葡萄球菌和4,330株金黄色葡萄球菌(银黄色葡萄球菌与金黄色葡萄球菌的比率：0.0055)。12株银链霉菌中有一半属于MLST序列类型(ST)2250及其单基因座变异，具有葡萄球菌凝固酶基因(CoA-)xid，其余的菌株分别属于ST2198/CoA-XIV(n=6)和ST1223(n=6)，其中CoA-XV是本研究发现的新的CoA-XV。除ST2198株BLAZ和ST2250株TET(L)分别对氨苄西林和四环素类药物耐药外，其余菌株均为mecA阴性，对所有受试菌均敏感。除溶血素基因(h1a、hlb和hld)分布广泛外，常见的毒力因子有ST2250的葡萄球菌肠毒素(类)基因Sey、SelZ、sel26和sel27，ST2198的selx和ST1223的肠毒素基因簇(egc-1：seg-sei-sem-sen-seo)。所有分离株的弹性蛋白结合蛋白基因(EBPs)和MSCRAMM家族粘附素SdrE基因(SdrE)具有较高的序列同源性(~gt；97%)，而与金黄色葡萄球菌的同源性较低(78~92%)。与Sec、SelZ、Tst-1和葡激酶基因(Sak)不同，银链球菌的EBPs、sdrE、selx、Sey、selw、sel26和sel27形成了不同于金黄色葡萄球菌的簇。本研究揭示了银链球菌在日本北部临床分离株中的流行情况，以及三个不同的银链球菌克隆(ST2250、ST2198和ST1223)的存在，它们具有不同的毒力因子。ST2198银链霉菌是一株少有报道的小克隆(类BN75菌株)，在日本首次被鉴定为人类分离株。
Staphylococcus argenteus, a novel emerging species within Staphylococcus aureus complex (SAC), has been increasingly reported worldwide. In this study, prevalence of S. argenteus among human clinical isolates, and their clonal diversity and genetic characteristics of virulence factors were investigated in Hokkaido, the northern main island of Japan. During a four-month period starting from March 2019, twenty-four S. argenteus and 4330 S. aureus isolates were recovered from clinical specimens (the ratio of S. argenteus to S. aureus :0.0055). Half of S. argenteus isolates (n = 12) belonged to MLST sequence type (ST) 2250 and its single-locus variant, with staphylocoagulase genotype (coa-) XId, while the remaining isolates were assigned to ST2198/coa-XIV (n = 6), and ST1223 with a novel coa-XV identified in this study (n = 6). All the isolates were mecA-negative, and susceptible to all the antimicrobials tested, except for an ST2198 isolate with blaZ and an ST2250 isolate with tet(L) showing resistance to ampicillin and tetracyclines, respectively. Common virulence factors in the S. argenteus isolates were staphylococcal enterotoxin (-like) genes sey, selz, sel26, and sel27 in ST2250, selx in ST2198, and enterotoxin gene cluster (egc-1: seg-sei-sem-sen-seo) in ST1223 isolates, in addition to hemolysin genes (hla, hlb, and hld) distributed universally. Elastin binding protein gene (ebpS) and MSCRAMM family adhesin SdrE gene (sdrE) detected in all the isolates showed high sequence identity among them (> 97%), while relatively lower identity to those of S. aureus (78-92%). Phylogenetically, ebpS, sdrE, selx, sey, selw, sel26, and sel27 of S. argenteus formed clusters distinct from those of S. aureus, unlike sec, selz, tst-1, and staphylokinase gene (sak). The present study revealed the prevalence of S. argenteus among clinical isolates, and presence of three distinct S. argenteus clones (ST2250; ST2198 and ST1223) harboring different virulence factors in northern Japan. ST2198 S. argenteus, a minor clone (strain BN75-like) that had been rarely reported, was first identified in Japan as human isolates.