Kim Nak-Hyun, Han Woong-Dae, Song Kyoung-Ho, Seo Hye-Kyung, Shin Myoung-jin, Kim Taek Soo, Park Kyoung Un, Ahn Soyeon, Yoo Jung Sik, Kim Eu Suk, Kim Hong Bin
Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
Division of Infectious Diseases, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
Am J Infect Control. 2014 Dec;42(12):1270-3. doi: 10.1016/j.ajic.2014.09.004. Epub 2014 Nov 25.
Carbapenem-resistant Enterobacteriaceae (CRE) are a growing problem worldwide. Guidelines focus on carbapenemase-producing organisms, and little is known about whether strict adherence to infection control measures is effective for CRE without carbapenemase. During 2009, CRE increased markedly in a tertiary hospital, and enhanced infection control measures without active surveillance were adopted.
Beginning in April 2010, enhanced antimicrobial stewardship, strict contact precautions, and cohort isolation were adopted. After September 2010, hand hygiene performance was prospectively monitored by active surveillance, and results were monthly fed back to medical personnel. Available carbapenem-resistant Escherichia coli (ECO) and carbapenem-resistant Klebsiella pneumoniae (KPN) isolated during 2008-2010 were characterized. Imipenem and meropenem minimal inhibitory concentrations were confirmed by E-test (AB biodisk, Solna, Sweden). Phenotypic screening assays and polymerase chain reaction (PCR) amplification of known β-lactamase and carbapenemase genes were performed.
From 3,511 ECO and 2,279 KPN, 44 (0.76%) were CRE (3 ECO, 41 KPN). CRE incidence rates rose from 1.61 in 2008 to 5.49 in 2009; they rose further to 9.81 per 100,000 patient days in early 2010. After adoption of strict infection control measures, CRE frequency fell back in 2011 and remained at baseline afterward. Phenotypic screening and PCR showed AmpC β-lactamase and extended spectrum β-lactamases with or without loss of porins; carbapenemases were not detected.
Enhanced infection control measures, even without active surveillance, seem effective to prevent further spread of CRE in a low-prevalence setting with mainly carbapenemase-nonproducing CRE.
耐碳青霉烯类肠杆菌科细菌（CRE）在全球范围内是一个日益严重的问题。指南主要关注产碳青霉烯酶的微生物，而对于严格遵守感染控制措施对不产碳青霉烯酶的CRE是否有效知之甚少。2009年期间，一家三级医院的CRE显著增加，随后采取了加强感染控制措施但未进行主动监测。
从2010年4月开始，采取了强化抗菌药物管理、严格的接触预防措施和群组隔离。2010年9月之后，通过主动监测对手部卫生执行情况进行前瞻性监测，并将结果每月反馈给医务人员。对2008 - 2010年期间分离出的可用耐碳青霉烯类大肠埃希菌（ECO）和耐碳青霉烯类肺炎克雷伯菌（KPN）进行特征分析。通过E试验（AB生物盘，瑞典索尔纳）确认亚胺培南和美罗培南的最低抑菌浓度。进行表型筛选试验以及已知β-内酰胺酶和碳青霉烯酶基因的聚合酶链反应（PCR）扩增。
在3511株ECO和2279株KPN中，44株（0.76%）为CRE（3株ECO，41株KPN）。CRE发病率从2008年的1.61上升至2009年的5.49；在2010年初进一步升至每100000患者日9.81。采取严格的感染控制措施后，CRE发生率在2011年回落，之后保持在基线水平。表型筛选和PCR显示存在AmpCβ-内酰胺酶和超广谱β-内酰胺酶，伴有或不伴有孔蛋白缺失；未检测到碳青霉烯酶。
即使没有主动监测，强化感染控制措施似乎对于在主要为不产碳青霉烯酶的CRE的低流行环境中预防CRE的进一步传播是有效的。
