Popovich Kyle J, Snitkin Evan S, Hota Bala, Green Stefan J, Pirani Ali, Aroutcheva Alla, Weinstein Robert A
Division of Infectious Diseases, Rush University Medical Center/Stroger Hospital of Cook County, Chicago, Illinois.
Department of Microbiology and Immunology, Division of Infectious Diseases, University of Michigan, Ann Arbor.
J Infect Dis. 2017 Jun 1;215(11):1640-1647. doi: 10.1093/infdis/jiw647.
We examined whether disparities existed in hospital-onset (HO) Staphylococcus aureus bloodstream infections (BSIs) and used whole-genome sequencing (WGS) to identify factors associated with USA300 transmission networks.
We evaluated HO methicillin-susceptible S. aureus (MSSA) and HO methicillin-resistant S. aureus (MRSA) BSIs for 2009-2013 at 2 hospitals and used an adjusted incidence for modeling. WGS and phylogenetic analyses were performed on a sample of USA300 BSI isolates. Epidemiologic data were analyzed in the context of phylogenetic reconstructions.
On multivariate analysis, male sex, African-American race, and non-Hispanic white race/ethnicity were significantly associated with HO-MRSA BSIs whereas Hispanic ethnicity was negatively associated (rate ratio, 0.41; P = .002). Intermixing of community-onset and HO-USA300 strains on the phylogenetic tree indicates that these strains derive from a common pool. African-American race was the only factor associated with genomic clustering of isolates.
In a multicenter assessment of HO-S. aureus BSIs, African-American race was significantly associated with HO-MRSA but not MSSA BSIs. There appears to be a nexus of USA300 community and hospital transmission networks, with a community factor being the primary driver. Our data suggest that HO-USA300 BSIs likely are due to colonizing strains acquired in the community before hospitalization. Therefore, prevention efforts may need to extend to the community for maximal benefit.
我们研究了医院获得性（HO）金黄色葡萄球菌血流感染（BSIs）中是否存在差异，并使用全基因组测序（WGS）来识别与USA300传播网络相关的因素。
我们评估了2009 - 2013年两家医院的医院获得性甲氧西林敏感金黄色葡萄球菌（MSSA）和医院获得性耐甲氧西林金黄色葡萄球菌（MRSA）血流感染情况，并使用调整后的发病率进行建模。对USA300血流感染分离株的样本进行了WGS和系统发育分析。在系统发育重建的背景下分析了流行病学数据。
多变量分析显示，男性、非裔美国人种族以及非西班牙裔白人种族与医院获得性耐甲氧西林金黄色葡萄球菌血流感染显著相关，而西班牙裔种族则呈负相关（率比，0.41；P = 0.002）。系统发育树上社区获得性和医院获得性USA300菌株的混合表明这些菌株源自一个共同的库。非裔美国人种族是与分离株基因组聚类相关的唯一因素。
在一项关于医院获得性金黄色葡萄球菌血流感染的多中心评估中，非裔美国人种族与医院获得性耐甲氧西林金黄色葡萄球菌血流感染显著相关，但与医院获得性甲氧西林敏感金黄色葡萄球菌血流感染无关。USA300社区和医院传播网络似乎存在联系，社区因素是主要驱动因素。我们的数据表明，医院获得性USA300血流感染可能是由于住院前在社区获得的定植菌株引起的。因此，预防措施可能需要扩展到社区以获得最大益处。
