Abstract

Background

Prevention and control of methicillin-resistant Staphylococcus aureus (MRSA) infections remain challenging. In-depth surveillance integrating patient and isolate data can provide evidence to better inform infection control and public health practice.

Methods

We analyzed MRSA cases diagnosed in 2010 (n = 212) and 2016 (n = 214) by hospitals in Ontario, Canada. Case-level clinical and demographic data were integrated with isolate characteristics, including antimicrobial resistance (AMR), classic genotyping, and whole-genome sequencing results.

Results

Community-associated MRSA (epidemiologically defined) increased significantly from 23.6% in 2010 to 43.0% in 2016 (P < .001). The MRSA population structure changed over time, with a 1.5× increase in clonal complex (CC)8 strains and a concomitant decrease in CC5. The clonal shift was reflected in AMR patterns, with a decrease in erythromycin (86.7% to 78.4%, P = .036) and clindamycin resistance (84.3% to 47.9%, P < .001) and a >2-fold increase in fusidic acid resistance (9.0% to 22.5%, P < .001). Isolates within both CC5 and CC8 were relatively genetically diverse. We identified 6 small genomic clusters—3 potentially related to transmission in healthcare settings.

Conclusions

Community-associated MRSA is increasing among hospitalized individuals in Ontario. Clonal shifting from CC5 to CC8 has impacted AMR. We identified a relatively high genetic diversity and limited genomic clustering within these dominant CCs.

中文翻译：

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加拿大安大略省住院患者中侵袭性MRSA感染的基因组流行病学。

摘要

背景

耐甲氧西林金黄色葡萄球菌（MRSA）感染的预防和控制仍然充满挑战。结合患者数据和隔离数据的深入监视可以提供证据，以更好地告知感染控制和公共卫生实践。

方法

我们分析了2010年（n  = 212）和2016（n  = 214）在加拿大安大略省的医院诊断出的MRSA病例。病例级临床和人口统计学数据与分离物特征整合在一起，包括抗菌素耐药性（AMR），经典基因分型和全基因组测序结果。

结果

与社区相关的MRSA（根据流行病学定义）从2010年的23.6％大幅增加到2016年的43.0％（P  <.001）。MRSA种群结构随时间变化，克隆复合物（CC）8菌株增加1.5倍，CC5随之减少。克隆转移反映在AMR模式中，红霉素减少（86.7％至78.4％，P  = .036）和克林霉素耐药性（84.3％至47.9％，P  <.001），而夫西地霉素的增加> 2倍耐酸性（9.0％至22.5％，P  <.001）。CC5和CC8内的分离株在遗传上相对不同。我们确定了6个小的基因组簇，其中3个可能与医疗机构中的传播有关。

结论

安大略省住院患者中与社区相关的MRSA在增加。从CC5到CC8的克隆迁移已影响AMR。我们在这些显性CC中发现了相对较高的遗传多样性和有限的基因组聚类。