Strategies to Reduce Transmission of Antimicrobial Resistant Bacteria

这是一项于2007年完成的为期18个月的多中心研究，旨在确定在成人重症监护病房(ICU)中，与仅使用标准护理的ICU相比，成人重症监护病房(ICU)中患者的定殖率和2种革兰氏阳性菌-甲氧西林耐药金黄色葡萄球菌(MRSA)和万古霉素耐药肠球菌(VRE)的感染率是否较低。强化控制策略包括：(1)通过对前鼻孔(MRSA)和粪便或肛周区域(VRE)进行前瞻性监测培养，确定感染MRSA或VRE的患者；(2)普遍戴手套，直到患者出院或其监测培养结果显示他们没有感染MRSA或VRE；以及(3)在护理感染MRSA或VRE的患者期间采取预防接触措施。分布在美国各地的19个ICU地点参加了这项研究。在所有患者入院时、每周ICU期间和出院时收集强化控制人群的监测培养。所有标本均在临床中心微生物学实验室处理。用增菌肉汤技术和选择性琼脂培养法对标本进行MRSA或VRE筛选，并用聚合酶链式反应(PCR)检测耐药基因。相当大比例的患者在研究期间被定植：MRSA-39%在标准对照人群中；VRE-56%在强化对照人群中，69%在标准对照人群中。在使用强化控制和标准控制策略的ICU之间，新的MRSA或VRE定植或感染事件的发生率没有显著差异。这项多中心、整群随机对照试验的结果表明，与使用标准手部卫生以及医护人员使用长袍和手套的标准做法相比，针对MRTSA和VRE使用基于培养的积极监测的策略在减少MRSA和VRE的传播方面并不有效。所有MRSA和VRE分离株都已储存在-80℃下，以供未来研究，如耐药基因的特征，对其他抗生素的耐药性评估(例如，MRSA对万古霉素的耐药性)，以及对菌株之间差异的流行病学分析。还启动了其他研究，以比较培养技术与通过核酸扩增技术直接检测耐药细菌的情况。

This was an 18-month multicenter study completed in 2007 that determined if rates of colonization and infection with 2 resistant Gram-positive bacteria - methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) - among patients in adult intensive care units (ICUs) were lower in ICUs that used an intensive infection control strategy plus standard care compared to ICUs that used standard care alone. The intensive control strategy involves: (1) identifying patients who were colonized with MRSA or VRE by the use of prospective surveillance cultures of the anterior nares (for MRSA) and stool or perianal area (for VRE); (2) Universal Gloving until the patients were discharged or their surveillance culture results showed they were not colonized with MRSA or VRE; and (3) Contact Precautions during care of patients who were colonized with MRSA or VRE. Nineteen ICU sites distributed throughout the US were enrolled in the study. Surveillance cultures for the intensive control populations were collected on all patients at the time of admission to the ICU, weekly during their ICU stay, and at the time of discharged. All specimens were processed in the Clinical Center Microbiology Lab. Specimens were screened for MRSA or VRE using an enrichment broth technique and selective agar culture methods, and the resistance genes were detected by PCR. A substantial proportion of patients were colonized during the study: MRSA - 39% in both the standard and intensive control populations; VRE - 56% and 69% in the intensive and standard control populations, respectively. There was no significant difference in the incidence of new MRSA or VRE colonization or infection events between the ICUs using the intensive control or standard control strategies. The results of this multicenter, cluster-randomized controlled trial indicated that a strategy utilizing culture-based active surveilland for MRTSA and VRE was not effective in reducing transmission of MRSA and VRE when compared to standard practice employing standard hand hygiene and use of gowns and gloves by healthcare workers. All isolates of MRSA and VRE have been stored at -80 C for future studies, such as characterization of the resistance genes, assessment of resistance to other antibiotics (e.g., vancomycin resistance in MRSA), and epidemiologic analysis for strain to strain differences. Additional studies were also initiated to compare culture techniques with direct detection of resistant bacteria by nucleic acid amplification techniques.