Dotel Ravindra, O'Sullivan Matthew V N, Davis Joshua S, Newton Peter J, Gilbert Gwendolyn L
Centre for Infectious Diseases and Microbiology, Westmead Hospital, University of Sydney, Sydney, NSW, Australia; Infectious Diseases Staff Specialist, Blacktown Hospital, Sydney, Australia.
Centre for Infectious Diseases and Microbiology, Westmead Hospital, University of Sydney, Sydney, NSW, Australia; Marie Bashir Institute for Infectious Disease and Biosecurity, University of Sydney, Sydney, Australia.
Infect Dis Health. 2019 Aug;24(3):134-140. doi: 10.1016/j.idh.2019.04.002. Epub 2019 May 13.
To better understand the molecular epidemiology of MRSA and to assess the utility of 19-target binary typing we undertook large-scale epidemiological surveillance of MRSA from invasive and non-invasive clinical specimens, and screening swabs.
Binary typing was performed on clinical MRSA isolates collected in New South Wales (NSW), Australia between 01/01/2012 - 31/12/2017. Binary type (BT) predicted multilocus sequence type (ST) and spa types based on results from isolates which had been characterised by both methods.
7624 MRSA isolates were analysed of which 3581 (47%) were wounds or skin & softtissue isolates (W/SSTI), 2436 (32%) screening swabs, 469 (6%) blood cultures (BC), 780 (10%) others, and 358 (5%) unknown. We identified 731 BTs, 54 spa types, and 31 STs. ST239 was the commonest MRSA clone in 2012 (30%), but it decreased to 7% in 2017 (p <0.001). In contrast, <0.5% of MRSA were ST45 in 2012 compared to 14% in 2017 (p<0.001). An emergence of PVL-positive ST22 was also noted. Of all isolates, 28% (2122/7624) were lukS/PVL positive; the proportion, among prospectively collected isolates increased from 24% (1406/5858) to 33% (1933/5858) between 2012 and 2017 (p <0.0001). 43% (1534/3581) W/SSTI, 20% (95/469) BC and 10% (239/2436) screening swabs were PVL-positive.
A major change in the epidemiology of MRSA was noted with a decline of ST239, an emergence of ST45 and PVL-positive ST22, and a significant increase in PVL-positive isolates. Binary typing can be a useful routine laboratory test for prospective molecular surveillance of MRSA colonisation and infection.
为了更好地了解耐甲氧西林金黄色葡萄球菌（MRSA）的分子流行病学，并评估19靶点二元分型的实用性，我们对来自侵袭性和非侵袭性临床标本以及筛查拭子中的MRSA进行了大规模的流行病学监测。
对2012年1月1日至2017年12月31日期间在澳大利亚新南威尔士州（NSW）收集的临床MRSA分离株进行二元分型。根据两种方法都已鉴定的分离株结果，二元型（BT）预测多位点序列型（ST）和spa型。
分析了7624株MRSA分离株，其中3581株（47%）为伤口或皮肤及软组织分离株（W/SSTI），2436株（32%）为筛查拭子，469株（6%）为血培养（BC），780株（10%）为其他，358株（5%）未知。我们鉴定出731种BT、54种spa型和31种ST。ST239是2012年最常见的MRSA克隆（30%），但在2017年降至7%（p<0.001）。相比之下，2012年ST45的MRSA占比<0.5%，而2017年为14%（p<0.001）。还注意到PVL阳性的ST22出现。在所有分离株中，28%（2122/7624）为lukS/PVL阳性；在2012年至2017年期间，前瞻性收集的分离株中这一比例从24%（1406/5858）增加到33%（1933/5858）（p<0.0001）。43%（1534/3581）的W/SSTI、20%（95/469）的BC和10%（239/2436）的筛查拭子为PVL阳性。
注意到MRSA流行病学发生了重大变化，ST239下降，ST45和PVL阳性的ST22出现，PVL阳性分离株显著增加。二元分型可作为MRSA定植和感染前瞻性分子监测的有用常规实验室检测方法。
