Gómez-Gil Rosa, Romero-Gómez Maria Pilar, García-Arias Africa, Ubeda M Gallego, Busselo M Sota, Cisterna Ramón, Gutiérrez-Altés Avelino, Mingorance Jesus
Servicio de Microbiología y Parasitología and Unidad de Investigación, Hospital Universitario La Paz, 28046 Madrid, Spain.
Diagn Microbiol Infect Dis. 2009 Oct;65(2):175-9. doi: 10.1016/j.diagmicrobio.2009.06.010. Epub 2009 Aug 29.
We describe 12 cases of linezolid-resistant Enterococcus faecalis. The present study was done in 2 wards of Hospital Universitario La Paz in Madrid, Spain. The 2 wards involved were the intensive care unit (ICU) and reanimation unit. Twelve clinical strains of E. faecalis reported by the clinical laboratory as linezolid resistant based on MICs determined by E-test (AB Biodisk, Solna, Sweden) were collected between September 2005 and October 2006. The MIC of linezolid for all the resistant isolates was >128 microg/mL. The isolates were analyzed for the presence of the G2576T mutation by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) and pyrosequencing. Pyrosequencing showed that the first isolate had G and T at position 2576 in a 1:1 ratio, whereas the remaining ones had a wild type to mutant ratio of 1:3. PCR-RFLP showed that the mutations were in alleles 1, 3, and 4. The 12 isolates under investigation came from different patients but were indistinguishable by pulsed-field gel electrophoresis (n = 7) and repetitive extragenic palindromic sequence (REP)-PCR (n = 12). This is the first report of a clonal outbreak of linezolid-resistant E. faecalis in Spain. To prevent or minimize the emergence of resistance, we should use linezolid strictly after the therapeutic indications, courses of treatment should be kept as short as possible, and risk factors for resistance development should be considered before starting. In addition, we suggest that susceptibility testing of clinically significant Gram-positive pathogens should be done in all cases of treatment failure, and, depending on the local epidemiology of each ICU, it might be advisable to do it before starting treatment with linezolid.
我们描述了12例耐利奈唑胺的粪肠球菌病例。本研究在西班牙马德里的拉巴斯大学医院的两个病房进行。所涉及的两个病房是重症监护病房（ICU）和复苏病房。在2005年9月至2006年10月期间，收集了临床实验室根据E-test（AB Biodisk，索尔纳，瑞典）测定的最低抑菌浓度（MIC）报告为耐利奈唑胺的12株粪肠球菌临床菌株。所有耐药菌株的利奈唑胺MIC均>128μg/mL。通过聚合酶链反应（PCR）-限制性片段长度多态性（RFLP）和焦磷酸测序分析分离株中G2576T突变的存在情况。焦磷酸测序显示，第一株分离株在2576位的G和T比例为1:1，而其余分离株的野生型与突变型比例为1:3。PCR-RFLP显示突变存在于等位基因1、3和4中。所研究的12株分离株来自不同患者，但通过脉冲场凝胶电泳（n = 7）和重复外源性回文序列（REP）-PCR（n = 12）无法区分。这是西班牙耐利奈唑胺粪肠球菌克隆暴发的首次报告。为预防或尽量减少耐药性的出现，我们应严格根据治疗指征使用利奈唑胺，治疗疗程应尽可能缩短，并且在开始治疗前应考虑耐药性发展的危险因素。此外，我们建议在所有治疗失败的病例中对临床上重要的革兰氏阳性病原体进行药敏试验，并且根据每个ICU的当地流行病学情况，在开始使用利奈唑胺治疗前进行药敏试验可能是明智的。
