Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan.
Department of Infection Control and Laboratory Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan.
Microb Drug Resist. 2019 Oct;25(8):1164-1175. doi: 10.1089/mdr.2018.0468. Epub 2019 May 20.
Molecular epidemiological characteristics were investigated for 1,041 isolates of methicillin-resistant (MRSA) collected in a tertiary care hospital in northern Japan for a 4-year period (2011-2014). Genotypes (staphylococcal cassette chromosome [SCC], sequence type, , , 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 SCC type was IIa (87.2%), followed by IV (10.1%) and V (1.2%). The SCC IIa-MRSA belonged to coagulase genotype () 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-SCC IVa/-t008/-IIIa (USA300 clone), ST6-SCC IVb, and ST59-SCC V (Taiwanese clone). Arginine catabolic mobile element (ACME) type I and II' were identified in three and five isolates of ST8-SCC IVa and ST764-SCC 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 SCC IVl was the most common among SCC IV subtypes, and was carried by almost half of -IIIa isolates (47%, 34/72) without PVL genes, which represented the novel ST8 MRSA clone spreading in Japan (, "ST8/CA-MRSA/J"). Uncommon MRSA clones in Japan, ST72-SCC IV (South Korean clone), ST398 livestock-associated clone, and ST20 bovine-associated MRSA, were identified. Furthermore, we isolated PVL-negative ST8-SCC I/-IIIa and ST81-SCC V/-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.
对日本北部一家三级保健医院在四年期间（2011-2014 年）收集的 1041 株耐甲氧西林金黄色葡萄球菌（MRSA）进行了分子流行病学特征研究。通过多重/单重 PCR 和必要时的 PCR 直接测序，分析了分离株的基因型（葡萄球菌盒染色体 [SCC]、序列型、等）和耐药/毒力因子基因的存在情况。在这些 MRSA 中，主要的 SCC 型为 IIa（87.2%），其次是 IV（10.1%）和 V（1.2%）。SCC IIa-MRSA 属于凝固酶基因型（）IIa 和 ST5/ST764，它们是日本主要的卫生保健相关-MRSA（HA-MRSA）（纽约/日本克隆体）及其变体。仅在 5 株（0.5%）分离株中检测到杀白细胞素（PVL）基因，基因型为 ST8-SCC IVa/-t008/-IIIa（USA300 克隆体）、ST6-SCC IVb 和 ST59-SCC V（台湾克隆体）。在 ST8-SCC IVa 和 ST764-SCC IIa MRSA 中，分别鉴定出三种和五种 ARG 代谢移动元件（ACME）I 型和 II'。PVL-/ACME-分离株分为各种 ST/克隆复合体（CC），其中 CC1、CC5、CC8、CC89 和 CC121 较为常见。值得注意的是，SCC IVl 是 SCC IV 亚型中最常见的，几乎一半的 -IIIa 分离株（47%，34/72）没有 PVL 基因，这代表了日本流行的新型 ST8 MRSA 克隆体（，"ST8/CA-MRSA/J"）。在日本，还发现了罕见的 MRSA 克隆体，包括 ST72-SCC IV（韩国克隆体）、ST398 牲畜相关克隆体和 ST20 牛相关 MRSA。此外，我们还分离到了 PVL 阴性的 ST8-SCC I/-IIIa 和 ST81-SCC V/-VIIa MRSA，这些分离株被认为是假定的新型克隆体。本研究揭示了 HA-MRSA 的遗传多样性，包括潜在新兴的不同来源的克隆体。
