据JAMA最新研究披露，在西班牙的12个加护病房（ICU）中的对利奈唑胺和甲氧苯青霉素耐药的金黄色葡萄球菌（LRSA）的感染爆发与医院内的细菌传播和广泛使用抗菌药物利奈唑胺有关。利奈唑胺常常用于治疗严重的感染；而减少利奈唑胺的使用及感染控制的举措则与该感染爆发的消退有关。
对甲氧苯青霉素耐药的金黄色葡萄球菌（MRSA）是与治疗有关的感染的一个重大原因。对严重MRSA感染的治疗选项有限（例如，对与呼吸机使用有关的MRSA肺炎仅推荐使用利奈唑胺和糖肽[肽的一类]）。据文章的背景资料，利奈唑胺因为其抗菌谱、良好的安全特性、药代动力学/药效动力学及其有效性而被广泛用于重症患者的治疗。对利奈唑胺耐药的金黄色葡萄球菌极为罕见。
Hospital Clinico San Carlos 及 Universidad Complutense, Madrid, Spain的Miguel Sanchez Garcia, M.D., Ph.D. 及其同僚对一次LRSA的爆发及其所应用的感染控制举措进行了检查。该项研究包括了在西班牙马德里的一家有1000个床位的三级大学教学医院的重症加护部门的身上存在或感染了LRSA的重症病人。
在2008年4月13日至6月26日期间发现了12名LRSA患者。有6位病人的LRSA引起了与呼吸机有关的肺炎，有3位病人则引起了LRSA的菌血症。在所有的分离菌株中的利奈唑胺的耐药性都证明与cfr基因相关。文章的作者写道：“除了一例之外，其它的可能的医院人员耐药菌携带者和环境样本皆呈阴性。有6名病人死亡，其中5名是ICU患者，其中一人的死亡被归因于LRSA感染。利奈唑胺从2008年4月的每日202次规定剂量的使用降低至2008年7月的25次规定剂量的使用。在2008年7月至2010年4月期间，在每周的监控培养或诊断性样本中没有发现新发的耐药病例。”
文章的作者写道：“在ICU中发生12名患者的LRSA感染爆发的报告据我们所知还是第一次，而且它也是与cfr基因介导的利奈唑胺抗药性的第一次报道。表观风险因子是以往对利奈唑胺的使用。”
“鉴于目前社区获得性MRSA感染的增加，我们的数据对住院病人和门诊病人都具有重要的意义。抗菌药物利福平和梭链孢酸的组合疗法仍然需要在临床的环境中进行评估。”（生物谷Bioon.com）
生物谷推荐原文出处：
JAMA. 2010;303[22]:2260-2264
Clinical Outbreak of Linezolid-Resistant Staphylococcus aureus in an Intensive Care Unit
Miguel Sánchez García, MD, PhD; María ángeles De la Torre, MD; Gracia Morales, PhD; Beatriz Peláez, PhD; María José Tolón, MD; Sara Domingo, MD; Francisco Javier Candel, MD, PhD; Raquel Andrade, PhD; Ana Arribi, MD, PhD; Nicolás García, MD; Fernando Martínez Sagasti, MD, PhD; José Fereres, MD, PhD; Juan Picazo, MD, PhD
Context Linezolid resistance is extremely uncommon in Staphylococcus aureus.
Objective To report an outbreak with linezolid and methicillin-resistant S aureus (LRSA) in an intensive care department and the effective control measures taken.
Design, Setting, and Patients Outbreak study of consecutive critically ill patients colonized and/or infected with LRSA at an intensive care department of a 1000-bed tertiary care university teaching hospital in Madrid, Spain. Patients were placed under strict contact isolation. Daily updates of outbreak data and recommendations for the use of linezolid were issued. Extensive environmental sampling and screening of the hands of health care workers were performed.
Main Outcome Measures Linezolid use and clinical and epidemiological characteristics and outcomes using minimal inhibitory concentrations, pulsed-field gel electrophoresis, and polymerase chain reaction of LRSA isolates.
Results Between April 13 and June 26, 2008, 12 patients with LRSA were identified. In 6 patients, LRSA caused ventilator-associated pneumonia and in 3 patients it caused bacteremia. Isolates were susceptible to trimethoprim-sulfamethoxazole, glycopeptides, tigecycline, and daptomycin. Genotyping identified 1 predominant clone and 3 other types. Cfr-mediated linezolid resistance was demonstrated in all isolates. Potential hospital staff carriers and environmental samples were negative except for one. Six patients died, 5 of them in the intensive care unit, with 1 death attributed to LRSA infection. Linezolid use decreased from 202 defined daily doses in April 2008 to 25 defined daily doses in July 2008. Between July 2008 and April 2010, no new cases have been identified in the weekly surveillance cultures or diagnostic samples.
Conclusions The first clinical outbreak, to our knowledge, with LRSA mediated by the cfr gene developed at our center, was associated with nosocomial transmission and extensive usage of linezolid. Reduction of linezolid use and infection-control measures were associated with the termination of the outbreak.
