Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia 30303, USA.
Infect Control Hosp Epidemiol. 2011 Nov;32(11):1057-63. doi: 10.1086/662178. Epub 2011 Sep 20.
The multicenter, cluster-randomized Strategies to Reduce Transmission of Antimicrobial Resistant Bacteria in Intensive Care Units (STAR*ICU) trial was performed in 18 U.S. adult intensive care units (ICUs). It evaluated the effectiveness of infection control strategies to reduce the transmission of methicillin-resistant Staphylococcus aureus (MRSA) colonization and/or infection. Our study objective was to examine the molecular epidemiology of MRSA and assess the prevalence and risk factors for community acquired (CA)-MRSA genotype nasal carriage at the time of ICU admission.
Selected MRSA isolates were subjected to molecular typing using pulsed-field gel electrophoresis.
Of 5,512 ICU patient admissions in the STAR*ICU trial during the intervention period, 626 (11%) had a nares sample culture result that was positive for MRSA. A total of 210 (34%) of 626 available isolates were selected for molecular typing by weighted random sampling. Of 210 patients, 123 (59%) were male; mean age was 63 years. Molecular typing revealed that 147 isolates (70%) were the USA100 clone, 26 (12%) were USA300, 12 (6%) were USA500, 8 (4%) were USA800, and 17 (8%) were other MRSA genotypes. In a multivariate analysis, patients who were colonized with a CA-MRSA genotype (USA300, USA400, or USA1000) were less likely to have been hospitalized during the previous 12 months (PR [prevalence ratio], 0.39 [95% confidence interval (CI), 0.21-0.73]) and were less likely to be older (PR, 0.97 [95% CI, 0.95-0.98] per year) compared with patients who were colonized with a healthcare-associated (HA)-MRSA genotype.
CA-MRSA genotypes have emerged as a cause of MRSA nares colonization among patients admitted to adult ICUs in the United States. During the study period (2006), the predominant site of CA-MRSA genotype acquisition appeared to be in the community.
多中心、整群随机的减少重症监护病房中抗生素耐药菌传播策略（STAR*ICU）试验在美国 18 个成人重症监护病房（ICU）进行。该试验评估了感染控制策略的有效性，以减少耐甲氧西林金黄色葡萄球菌（MRSA）定植和/或感染的传播。我们的研究目的是研究 MRSA 的分子流行病学，并评估 ICU 入院时社区获得性（CA）-MRSA 基因型鼻腔携带的患病率和危险因素。
选择的 MRSA 分离株进行脉冲场凝胶电泳的分子分型。
在 STAR*ICU 试验的干预期间，5512 例 ICU 患者入院，626 例（11%）鼻拭子培养结果为 MRSA 阳性。共有 210 份（626 份中可获得的）可用分离株通过加权随机抽样进行了分子分型。210 例患者中，123 例（59%）为男性；平均年龄为 63 岁。分子分型显示，147 株（70%）为 USA100 克隆，26 株（12%）为 USA300，12 株（6%）为 USA500，8 株（4%）为 USA800，17 株（8%）为其他 MRSA 基因型。多变量分析显示，定植 CA-MRSA 基因型（USA300、USA400 或 USA1000）的患者在过去 12 个月内住院的可能性较小（患病率比[PR]，0.39 [95%置信区间（CI），0.21-0.73]），年龄较大的可能性也较小（PR，每增加 1 年 0.97 [95% CI，0.95-0.98]）与定植 HA-MRSA 基因型的患者相比。
CA-MRSA 基因型已成为美国成人 ICU 入院患者 MRSA 鼻腔定植的原因之一。在研究期间（2006 年），CA-MRSA 基因型获得的主要部位似乎是社区。
