Department of Ocular Microbiology, Aravind Eye Hospital, Madurai, India.
Department of Uvea, Aravind Eye Hospital, Madurai, India.
Infect Genet Evol. 2019 Apr;69:203-210. doi: 10.1016/j.meegid.2019.01.031. Epub 2019 Jan 30.
Methicillin-resistant Staphylococcus aureus (MRSA) is an important cause of vision threatening ocular infections. This study aimed to determine the prevalence and antimicrobial susceptibility pattern of MRSA and their genotypic characterization in ocular infections. The study period was from January 2007 to December 2017 in Aravind Eye Hospital, Madurai. Retrospective analysis of clinical records found a total of 1306 Staphylococcus aureus in various ocular infections. Among these, 274 (21%) were found to be MRSA with an increased incidence from 9% in 2007 to 38% in 2017 (P = .007). MRSA was isolated commonly from lacrimal sac infection 89 (32%), lid infection 55 (20%), keratitis 45 (16%) and orbital infection 34 (12%). MRSA isolates showed 100% sensitivity to vancomycin, 91% to chloramphenicol and majority of MRSA isolates were resistant to all fluoroquinolones. MSSA strains showed very minimal resistance to chloramphenicol (5%) and also there was no resistance to vancomycin. In case of the MSSA isolates, resistance to fluroquinolones (ciprofloxacin, gatifloxacin, moxifloxacin, ofloxacin and levofloxacin) was found to increase during study period. Methicillin-resistance is conferred by the carriage of Staphylococcal Cassette Chromosome mec (SCCmec) and most of our isolates were belonged to SCCmec type V and IV which is known to be community acquired MRSA. MLST sequencing on seven housekeeping genes revealed, sequence type ST772 was predominant followed by ST22. Agr typing identified most of the isolates (69) were agr type II (77%). By spa typing, there are 16 spa types were identified, among which 60% of the isolates had t657 spa type.
耐甲氧西林金黄色葡萄球菌（MRSA）是一种导致威胁视力的眼部感染的重要原因。本研究旨在确定眼部感染中 MRSA 的流行率和抗菌药物敏感性模式及其基因型特征。研究期间为 2007 年 1 月至 2017 年 12 月，在 Aravind 眼科医院，马杜赖。对临床记录的回顾性分析发现，在各种眼部感染中共有 1306 株金黄色葡萄球菌。其中，274 株（21%）被鉴定为 MRSA，其发病率从 2007 年的 9%增加到 2017 年的 38%（P=0.007）。MRSA 通常从泪囊感染中分离出来 89 株（32%）、眼睑感染 55 株（20%）、角膜炎 45 株（16%）和眼眶感染 34 株（12%）。MRSA 分离株对万古霉素的敏感性为 100%，对氯霉素的敏感性为 91%，大多数 MRSA 分离株对所有氟喹诺酮类药物均耐药。MSSA 株对氯霉素的耐药性非常低（5%），对万古霉素也没有耐药性。对于 MSSA 分离株，在研究期间发现对氟喹诺酮类药物（环丙沙星、加替沙星、莫西沙星、氧氟沙星和左氧氟沙星）的耐药性增加。耐甲氧西林是由携带葡萄球菌盒染色体 mec（SCCmec）引起的，我们的大多数分离株属于已知的社区获得性 MRSA 的 SCCmec 类型 V 和 IV。对七个管家基因的 MLST 测序显示，优势序列类型 ST772 其次是 ST22。agr 分型鉴定出大多数分离株（69%）为 agr 型 II（77%）。通过 spa 分型，共鉴定出 16 种 spa 型，其中 60%的分离株具有 t657 spa 型。
