Strategies to Reduce Transmission of Antimicrobial Resis

这是一项为期18个月的多中心研究，旨在确定两种耐药革兰氏阳性细菌——耐甲氧西林金黄色葡萄球菌（MRSA）和耐万古霉素肠球菌（VRE）——在成人重症监护病房（icu）患者中，使用强化感染控制策略加标准护理的icu患者的定植和感染率是否低于单独使用标准护理的icu患者。强化控制策略包括：(1)通过使用鼻腔（MRSA）和粪便或肛周区域（VRE）的前瞻性监测培养来识别MRSA或VRE定殖的患者；(2)佩戴通用手套，直到患者出院或监测培养结果表明患者没有MRSA或VRE定植；(3) MRSA或VRE定殖患者护理期间的接触注意事项。分布在美国各地的19家ICU医院参与了这项研究。在所有患者入ICU时、ICU住院期间每周和出院时收集强化对照人群的监测培养物。所有标本（约100,000）将在临床中心微生物实验室进行处理。采用富集肉汤技术和选择性琼脂培养法对标本进行MRSA或VRE筛选，并采用PCR检测抗性基因。在开展了富集和选择性培养方法的初步工作后，开始了研究。研究的前6个月阶段已接近完成。VRE和MRSA定植的发生率在每个ICU和每个月都有所不同。然而，平均15%的鼻拭子和25%的直肠拭子分别对MRSA和VRE呈阳性。MRSA和VRE的所有分离株均已保存在-80℃，用于未来的研究，如耐药基因的表征，对其他抗生素的耐药性评估（例如MRSA对万古霉素的耐药性），以及菌株间差异的流行病学分析。另外的研究已经开始比较培养技术和核酸扩增技术直接检测耐药细菌。

This is an 18-month multicenter study to determine if rates of colonization and infection with 2 resistant Gram-positive bacteria - methicillin reseistant Staphylococcus aureus (MRSA) and vancomycin resistant Enterococcus (VRE) - among patients in adult intensive care units (ICUs) are lower in ICUs that use an intensive infection control strategy plus standard care compared to ICUs that use standard care alone. The intensive control strategy involves: (1) identifying patients who are 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 are discharged or their surveillance culture results shoe they are not colonized with MRSA or VRE; and (3) Contact Precautions during care of patients who arre colonized with MRSA or VRE. Nineteen ICU sites distributed throughout the US are enrolled in the study. Surveillance cultures for the intensive control populations are 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 (approximately 100,000) will be processed in the Clinical Center Microbiology Labs. Specimens will be screened for MRSA or VRE using an enrichment broth technique and selective agar culture methods, and the resistance genes will be detected by PCR. After preliminary work was performed developing the enrichment and selective culture methods, the study was initiated. The first 6 month phase of the study is nearing completion. The incidence of VRE and MRSA colonization varies for each ICU and from month to month. However, an average of 15% of the nasal swabs and 25% of the rectal swabs were positive for MRSA and VRE, respectively. 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 have been initiated to compare culture techniques with direct detection of resistant bacteria by nucleic acid amplification techniques.