Clonal Diversity and Genetic Characteristics of Methicillin-Resistant Staphylococcus aureus Isolates from a Tertiary Care Hospital in Japan
Clonal Diversity and Genetic Characteristics of Methicillin-Resistant Staphylococcus aureus Isolates from a Tertiary Care Hospital in Japan
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DOI：
10.1089/mdr.2018.0468
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发表时间：
2019-10-01
影响因子：
2.6
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
对在日本北方三级医院收集的1，041株耐甲氧西林金黄色葡萄球菌（MRSA）分离株进行了为期4年（2011-2014年）的分子流行病学特征研究。基因型（葡萄球菌盒式染色体mec [SCCmec]、序列型、spa、coa等）采用多重/单重PCR和PCR-直接测序技术检测耐药/毒力因子基因。在这些MRSA中，SCCmec型以IIa型为主（87.2%），其次为IV型（10.1%）和V型（1.2%）。SCCmec IIa-MRSA属于凝固酶基因型（coa）IIa和ST 5/ST 764，在日本（纽约/日本克隆）及其变异株被称为主要医疗保健相关MRSA（HA-MRSA）。Panton-Valentine杀白细胞素（PVL）基因仅在5株（0.5%）分离株中检测到，其基因型为ST 8-SCCmec IVa/spa-t008/coa-IIIa（USA 300克隆）、ST 6-SCCmec IVb和ST 59-SCCmec V（台湾克隆）。分别在ST 8-SCCmec IVa和ST 764-SCCmec IIa MRSA的3株和5株分离株中鉴定出精氨酸分解代谢移动的元件（ACME）I型和II '型。PVL-/ACME-分离株分为各种ST/克隆复合体（CC），常见的有CC 1、CC 5、CC 8、CC 89和CC 121。值得注意的是，SCCmec IV 1是SCCmec IV亚型中最常见的，并且由几乎一半的没有PVL基因的coa-IIIa分离株（47%，34/72）携带，这代表了在日本传播的新型ST 8 MRSA克隆（即，“ST8/CA-MRSA/J”）。鉴定了日本不常见的MRSA克隆，ST 72-SCCmec IV（韩国克隆）、ST 398家畜相关克隆和ST 20牛相关MRSA。此外，我们分离了PVL阴性ST 8-SCCmec I/coa-IIIa和ST 81-SCCmec V/coa-VIIa MRSA，它们被认为是推定的新克隆。本研究揭示了HA-MRSA的遗传多样性，包括可能出现的假定不同来源的克隆。
Molecular epidemiological characteristics were investigated for 1,041 isolates of methicillin-resistant Staphylococcus aureus (MRSA) collected in a tertiary care hospital in northern Japan for a 4-year period (2011-2014). Genotypes (staphylococcal cassette chromosome mec [SCCmec], sequence type, spa, coa, etc.) and the presence of drug resistance/virulence factor genes in the isolates were analyzed by multiplex/uniplex PCR, and PCR-direct sequencing as needed. Among these MRSA, predominant SCCmec type was IIa (87.2%), followed by IV (10.1%) and V (1.2%). The SCCmec IIa-MRSA belonged to coagulase genotype (coa) IIa and ST5/ST764, which are known as major health care-associated-MRSA (HA-MRSA) in Japan (New York/Japan clone) and its variant. Panton-Valentine leucocidine (PVL) genes were detected in only five isolates (0.5%) with genotypes ST8-SCCmec IVa/spa-t008/coa-IIIa (USA300 clone), ST6-SCCmec IVb, and ST59-SCCmec V (Taiwanese clone). Arginine catabolic mobile element (ACME) type I and II ' were identified in three and five isolates of ST8-SCCmec IVa and ST764-SCCmec IIa MRSA, respectively. PVL-/ACME- isolates were classified into various STs/clonal complexes (CCs), with CC1, CC5, CC8, CC89, and CC121 being common. It was notable that SCCmec IVl was the most common among SCCmec IV subtypes, and was carried by almost half of coa-IIIa isolates (47%, 34/72) without PVL genes, which represented the novel ST8 MRSA clone spreading in Japan (i.e., "ST8/CA-MRSA/J"). Uncommon MRSA clones in Japan, ST72-SCCmec IV (South Korean clone), ST398 livestock-associated clone, and ST20 bovine-associated MRSA, were identified. Furthermore, we isolated PVL-negative ST8-SCCmec I/coa-IIIa and ST81-SCCmec V/coa-VIIa MRSA, which were considered presumptive novel clones. The present study revealed the genetic diversity of HA-MRSA, including potentially emerging clones of putative different origins.