Community-associated strains of methicillin-resistant Staphylococccus aureus as the cause of healthcare-associated infection
Community-associated strains of methicillin-resistant Staphylococccus aureus as the cause of healthcare-associated infection
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DOI：
10.1086/507923
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发表时间：
2006-10-01
影响因子：
4.5
通讯作者：
Hulten, Kristina G.
中科院分区：
文献类型：
--
作者：
Gonzalez, Blanca E.;Rueda, Adriana M.;Hulten, Kristina G.
OBJECTIVE.来自社区相关感染患者的耐甲氧西林金黄色葡萄球菌（MRSA）分离株被描述为与来自医疗保健相关感染患者的菌株在遗传上不同的菌株。本研究检验了社区相关MRSA（CA-MRSA）菌株现在引起住院患者严重感染的假设。从2003年7月至2004年6月获得的血液分离株中随机选择37株临床MRSA分离株。对菌株进行葡萄球菌染色体盒mec（SCCmec）型、脉冲场凝胶电泳（PFGE）型和Panton-Valentine杀白细胞素（PVL）基因检测。由对细菌菌株分析结果不知情的研究者进行病历审查和流行病学分类。根据已建立的定义，血流感染的发作被独立分类为社区相关或医疗保健相关感染，细菌分离株被独立分类为CA-MRSA菌株或医疗保健相关MRSA（HA-MRSA）菌株。三级护理退伍军人事务医疗中心。37株MRSA分离株中有24株（65%）为SCCmec IV型，这是CA-MRSA菌株的遗传类型特征;这24株分离株中有22株属于CA-MRSA克隆USA 300，并携带PVL基因。37株SCCmec中有13株（35%）为SCCmec II型，其中12株为USA 100-ST 5，12株缺乏PVL基因。30例患者（81%）有医疗相关感染;其中18例（60%）感染了携带CA-MRSA菌株标记的分离株。在7例CA-MRSA感染患者中，6例感染了属于USA 300克隆的分离株。医疗保健相关血流感染患者与社区相关感染患者一样可能感染CA-MRSA菌株（P= 0.38）。具有CA-MRSA菌株分子特征的MRSA菌株已成为我院严重医疗相关感染的重要原因。
OBJECTIVE. Methicillin-resistant Staphylococcus aureus ( MRSA) isolates from patients with community-associated infection have been described as strains genetically distinct from the strains isolated from patients with healthcare-associated infection. This study examines the hypothesis that community-associated MRSA ( CA-MRSA) strains now cause serious infections in hospitalized patients.METHODS. Thirty-seven clinical MRSA isolates were randomly selected from blood isolates obtained from July 2003 through June 2004. Strains were tested for staphylococcal chromosomal cassette mec ( SCCmec) type, pulsed-field gel electrophoresis ( PFGE) type, and presence of Panton-Valentine leukocidin ( PVL) genes. Medical records review and epidemiologic classification was performed by an investigator blinded to the results of the bacterial strain analysis. Episodes of bloodstream infection were independently classified as either community-associated or healthcare-associated infections, and bacterial isolates were independently classified as either CA-MRSA strains or healthcare-associated MRSA ( HA-MRSA) strains, according to established definitions.SETTING. A tertiary care Veterans Affairs Medical Center.RESULTS. Twenty-four ( 65%) of 37 MRSA isolates were SCCmec type IV, a genetic type characteristic of CA-MRSA strains; 22 of these 24 isolates belonged to the CA-MRSA clone USA300 and carried PVL genes. Thirteen ( 35%) of the 37 strains were SCCmec type II, of which 12 were USA100-ST5 and 12 lacked PVL genes. Thirty patients ( 81%) had healthcare-associated infections; 18 ( 60%) of these 30 were infected with isolates carrying markers of CA-MRSA strains. Of 7 patients with CA- MRSA infections, 6 were infected with isolates belonging to the USA300 clone. Patients with healthcare-associated bloodstream infections were as likely to be infected with a CA-MRSA strain as patients with a community-associated infection (P=.38).CONCLUSIONS. MRSA strains with molecular characteristics of CA- MRSA strains have emerged as an important cause of serious healthcare-associated infection in our hospital.