State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital of Medicine School, Zhejiang University, Hangzhou, China.
Shenzhen Institute of Respiratory Diseases, the First Affiliated Hospital (Shenzhen People's Hospital), Southern University of Science and Technology, Shenzen, China.
J Antimicrob Chemother. 2019 Sep 1;74(9):2537-2543. doi: 10.1093/jac/dkz232.
Most vancomycin-intermediate Staphylococcus aureus (VISA) and heterogeneous VISA (hVISA) are derived from hospital-associated MRSA due to treatment failure; however, the prevalence of hVISA/VISA in community settings remains unclear.
Four hundred and seventy-six community-associated isolates were collected between 2010 and 2011 during national surveillance for antimicrobial resistance in 31 county hospitals across China. Drug susceptibility evaluation and mecA detection were performed by using broth microdilution and PCR analysis, respectively. hVISA/VISA were identified by using macro-Etest and a modified population analysis profile (PAP)-AUC method. The genetic features of all hVISA/VISA isolates were genotyped.
Among 476 isolates, MRSA and MSSA accounted for 19.7% (n = 94) and 80.3% (n = 382), respectively. Two VISA and 36 hVISA isolates were identified by PAP-AUC testing. The VISA isolates and 29 of the hVISA isolates were MRSA. The proportion of hVISA/VISA was significantly higher in MRSA (30.9%) than in MSSA (1.8%). The hVISA/VISA isolates were assigned to 18 STs classified into seven clonal complexes (CCs). CC121 (n = 12) followed by ST239 (n = 11) was the most prevalent hVISA/VISA clone. All ST239-hVISA/VISA were MRSA, while 12 CC121-hVISA isolates included 6 MSSA and 6 MRSA isolates. SCCmec III was predominant among MRSA-hVISA/VISA isolates. agr I and agr IV were detected in ST239 and CC121, respectively. All except two strains were positive for Panton-Valentine leucocidin genes.
To the best of our knowledge, this is the first report of CC121 as a prevalent hVISA clone in community settings, highlighting the necessity of surveillance and stricter infection control measures for this globally disseminated lineage.
大多数万古霉素中介金黄色葡萄球菌（VISA）和异质性 VISA（hVISA）是由于治疗失败而从医院相关的耐甲氧西林金黄色葡萄球菌（MRSA）中产生的；然而，社区环境中 hVISA/VISA 的流行率尚不清楚。
2010 年至 2011 年期间，在中国 31 家县医院进行的抗菌药物耐药性国家监测中，共收集了 476 株社区相关分离株。采用肉汤微量稀释法和 PCR 分析分别进行药物敏感性评价和 mecA 检测。采用宏 Etest 和改良的群体分析曲线（PAP）-AUC 法鉴定 hVISA/VISA。对所有 hVISA/VISA 分离株的遗传特征进行基因分型。
在 476 株分离株中，MRSA 和 MSSA 分别占 19.7%（n ⁇ 94）和 80.3%（n ⁇ 382）。通过 PAP-AUC 检测鉴定出 2 株 VISA 和 36 株 hVISA 分离株。VISA 分离株和 29 株 hVISA 分离株为 MRSA。MRSA 中 hVISA/VISA 的比例（30.9%）明显高于 MSSA（1.8%）。hVISA/VISA 分离株被分配到 18 个 ST 型，分为 7 个克隆复合体（CC）。CC121（n ⁇ 12）紧随其后的是 ST239（n ⁇ 11）是最常见的 hVISA/VISA 克隆。所有 ST239-hVISA/VISA 均为 MRSA，而 12 株 CC121-hVISA 分离株包括 6 株 MSSA 和 6 株 MRSA 分离株。MRSA-hVISA/VISA 分离株中以 SCCmec III 为主。ST239 中检测到 agr I，CC121 中检测到 agr IV。除 2 株外，所有菌株均为阳性，携带杀白细胞素基因 Panton-Valentine。
据我们所知，这是首次报道 CC121 是社区环境中流行的 hVISA 克隆，这突显了对这种全球传播谱系进行监测和更严格的感染控制措施的必要性。
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