Salso S, Culebras E, Andrade R, Picazo J J
Department of Clinical Microbiology, Hospital Clínico San Carlos, 28040 Madrid, Spain.
Microb Drug Resist. 2003 Fall;9(3):299-305. doi: 10.1089/107662903322286517.
Organisms encoding multidrug resistance genes are becoming increasingly prevalent. During a 2-month period (December, 2000, to January, 2001), 83 consecutive isolates of Enterobacter spp. were collected in our microbiology department. Antibiotic susceptibility was determined using the Vitek II automatic system. We selected strains with decreased susceptibility to extended-spectrum cephalosporins. The double-disk potentiation test was positive in 10 of these strains, indicating the presence of extended-spectrum beta-lactamases (ESBLs). Polymerase chain reaction (PCR), isoelectric focusing (IEF), and sequencing identified TEM 24 beta-lactamase in the 10 selected E. aerogenes. Random amplification of polymorphic DNA (RAPD-PCR) revealed the same clonal origin for all the strains tested and strongly suggest an outbreak of multidrug-resistant E. aerogenes. To follow up the trends in ESBLs-producing Enterobacter infections in the hospital over time, we repeated the study 1 year later (December, 2001, to February, 2002). Only three ESBLs-producing Enterobacter were found. All of them corresponded to the previously characterized clone.
携带多重耐药基因的微生物正变得越来越普遍。在2000年12月至2001年1月的2个月期间，我们微生物科连续收集了83株肠杆菌属菌株。使用Vitek II自动系统测定抗生素敏感性。我们选择了对超广谱头孢菌素敏感性降低的菌株。其中10株菌株的双纸片协同试验呈阳性，表明存在超广谱β-内酰胺酶（ESBLs）。聚合酶链反应（PCR）、等电聚焦（IEF）和测序在10株所选产气肠杆菌中鉴定出TEM 24β-内酰胺酶。随机扩增多态性DNA（RAPD-PCR）显示所有测试菌株具有相同的克隆起源，并强烈提示出现了多重耐药产气肠杆菌的暴发。为了跟踪医院中产ESBLs肠杆菌感染随时间的变化趋势，我们在1年后（2001年12月至2002年2月）重复了这项研究。仅发现3株产ESBLs肠杆菌。所有这些菌株都与先前鉴定的克隆一致。
