耐甲氧西林金黄色葡萄球菌分子流行病学研究

目的研究某院临床分离耐甲氧西林金黄色葡萄球菌(MRSA)分子流行病学特点,为临床预防、MRSA流行监测,制定防治方案等提供科学依据。方法采用药敏纸片法和PCR技术对从住院患者、医务人员及环境分离的MRSA进行表型、基因型鉴定,检测其杀白细胞毒素(pvl)基因,并进一步对mecA基因阳性标本进行SCCmec基因分型。结果从1352份标本中分离出108株金黄色葡萄球菌,MRSA为54株,主要分离于烧伤科占77.78%;根据SCCmec基因分型结果,54株MRSA以Ⅲ型为主,占68.52%,pvl基因均为阴性。结论某院MRSA临床检出率与2008年监测的数据相仿,流行情况以Ⅲ型SCCmec基因型为主,提示医院MRSA临床株与环境株之间MRSA可能具有同源性,临床必须采取严格措施加以控制。     

烧伤科耐甲氧西林金黄色葡萄球菌杀白细胞素基因检测及SCCmec分子流行病学调查

目的 研究临床分离的耐甲氧西林金黄色葡萄球菌(MRSA)分子流行病学特点,为临床预防MRSA流行、制定防治方案等提供科学依据.方法 采用聚合酶链反应(PCR技术)对烧伤科2010年4月14日-6月1日临床标本中分离的24株MRSA进行SCCmec分型及pvl基因检测;纸片扩散法检测MRSA对21种抗菌药物的耐药性.结果 24株MRSA中,SCCmecⅢ型20株占83.3％,4株未分型占16.7％,pvl基因均为阴性;SCCmecⅢ 型的菌株除对万古霉素、替考拉宁、利奈唑胺、喹奴普汀/达福普汀敏感以外,对其他抗菌药物均耐药.结论 医院烧伤科临床分离MRSA的SCCmec型别主要以SCCmecⅢ型为主,携带SCCmecⅢ型的MRSA对抗菌药物呈现多药耐药现象.     

儿童社区获得性、金黄色葡萄球菌肺炎的分子分型研究

目的了解金黄色葡萄球菌杀白细胞毒素(PVL)的分布特征以及耐甲氧西林金黄色葡萄球菌(MRSA)染色体mec(SCCmec)基因盒的分型情况。方法收集2015年1-3月在该院诊断为社区获得性肺炎患儿的非重复性金黄色葡萄球菌菌株141株(痰标本);用多重聚合酶链反应对金黄色葡萄球菌进行PVL基因检测和spa分型,对MRSA进行甲氧西林耐药决定子A(mecA)基因检测和SCCmec基因分型。结果 MRSA检出率为9.2%,均检出mecA基因;将141株金黄色葡萄球菌全部进行PVL基因检测,共检测PVL阳性菌株26株,其中从138株甲氧西林敏感的金黄色葡萄球菌(MSSA)中检出25株,占19.5%;从13株MRSA中检出1株,占7.7%。SCCmec分型结果 1株携带PVL基因的MRSA属于SCCmecⅢ型,其余12株MRSA有2株属于SCCmecⅢ型、10株属于SCCmecⅣ型。未检出SCCmecⅠ、Ⅱ和Ⅴ型。13株MRSA的spa分型未见典型的型别,比较分散;128株MSSA的spa分型以t132为主要型别,其次为t141、t124和t210。结论 MSSA携带PVL基因的阳性率高于MRSA,该院儿童社区获得MRSA以SCCmecⅣ型为主。Spa分型分析显示未见某一型菌株克隆流行,呈散发状态。     

47株金黄色葡萄球菌临床血流感染分离株的基因分型研究

目的 研究金黄色葡萄球菌临床血流感染分离株的分子流行病学特征.方法 收集2006年1月至2008年12月解放军总医院分离的临床血流感染金黄色葡萄球菌菌株(共47株),标本来源均为患者静脉血.采用琼脂稀释法检测所有菌株对多种抗生素的耐药性,PCR方法 检测pvl毒素基因,DiversiLab~(TM)Rep-PCR分型系统分析菌株的同源性;对耐甲氧西林金黄色葡萄球菌(MRSA)进行葡萄球菌染色体/mec(SCCmec)分型以及ST239型别的快速筛查;综合分型和药敏试验结果,挑选部分代表菌株进行多位点序列分型(MLST).结果 47株血流感染金黄色葡萄球菌中,pvl基因检出率为4.3%.MRSA占51.1%.MRSA均为SCCmec Ⅲ型菌株;Rep-PCR分为A～L共12个型,其中A型为最主要的型,共22株(46.8%),所有的MRSA均属于A、B两型.结论 47株临床血流感染金黄色葡萄球菌中的MRSA绝大部分为多重耐药克隆ST239-MRSA-SCCmecⅢ型.     

儿童耐甲氧西林金黄色葡萄球菌肺炎临床分离株分析

目的探讨儿童耐甲氧西林金黄色葡萄球菌(MRSA)肺炎临床分离株的分子分型特征、pvl基因携带及耐药性特点,为临床监控及治疗提供参考。方法收集2010-2015年4所医院MRSA肺炎住院患儿的临床资料和临床分离株共52株,分析其临床特点,对MRSA进行MLST、spa、SCCmec和agr分型;PCR方法检测分离株的pvl毒力基因;采用琼脂稀释法进行抗菌药物的体外药敏试验。结果 52例MRSA肺炎患儿中21例出现脓胸占40.5%,10例出现呼吸衰竭占19.2%,6例为坏死性肺炎占11.5%,21例同时合并肺外部位的感染占40.4%,5例患儿死亡,病死率9.6%;11种MLST型中ST59最常见占50.0%,其次为ST239占25.0%;SCCmec型中SCCmecⅣ占59.6%,SCCmecⅢ占28.8%;3种agr型中Ⅰ型占84.6%;ST59-SCCmec IV-t437型为主要流行克隆占44.2%;18株携带pvl基因占34.6%,主要存在于ST59型菌株中;pvl基因在坏死性肺炎分离株中的携带率明显高于非坏死性肺炎分离株(P0.05);所有菌株的多药耐药率为55.8%,对万古霉素、利奈唑胺、夫西地酸均敏感。结论 MRSA肺炎患儿常合并肺部并发症和肺外感染灶,病死率较高,ST59-SCCmec IVt437是儿童MRSA肺炎主要流行克隆,ST59型菌株是携带pvl基因的主要克隆,pvl基因与坏死性肺炎有相关性。     

内科病区金黄色葡萄球菌耐药性及分子流行特征分析

目的了解医院内科病区金黄色葡萄球菌临床分离株的分子特征及其对临床常用抗菌药物的耐药情况,为防控金黄色葡萄球菌感染及临床治疗提供依据。方法收集2011年6月-2016年3月期间乌鲁木齐地区一所三甲医院内科病区临床分离的202株金黄色葡萄球菌,应用PCR方法鉴定耐甲氧西林金黄色葡萄球菌(MRSA)和甲氧西林敏感金黄色葡萄球菌(MSSA),应用多位点序列分型(MLST),spa分型,SCCmec分型等方法进行分析,检测pvl毒力基因的携带率,采用VITEK-2Compact全自动微生物分析仪完成药敏试验。结果 202株金黄色葡萄球菌中78株为MRSA,124株为MSSA;78株MRSA分为5种ST型和9种spa型,优势流行克隆为CC5-ST239-MRSA-III-t030占71%;124株MSSA分为20种ST型,36种spa型,优势流行克隆为CC22-ST22-MSSA-t309;CC5-ST239-MRSA-III克隆是造成心脑血管病及呼吸道疾病患者感染的主要克隆;CC22-ST22-MSSA-t309则是引起肿瘤及肾脏病患者感染的主要克隆,而ST121-MSSA克隆主要在糖尿病患者中检出。MRSA菌株的pvl毒力基因检出率为14.1%,MSSA为41.9%;药敏结果显示主要流行克隆ST239-MRSA-III-t030具有两种主要耐药谱,MSSA中CC7克隆群为多药耐药菌株。结论医院内科病区流行的MRSA以ST239-MRSA-III-t030为主,MSSA以ST22-MSSA-t309为主,引起不同疾病感染的主要克隆存在差异,发现多药耐药及高毒力MSSA菌株。     

耐甲氧西林金黄色葡萄球菌SCCmec基因分型及耐药谱分析

目的 研究耐甲氧西林金黄色葡萄球菌(MRSA) SCCmec基因分型情况,并对其耐药谱进行分析.方法 收集从临床标本分离出的MRSA 91株,应用多重PCR法对MRSA进行SCCmec基因分型,采用MicroScanWalk-Away-40全自动微生物鉴定药敏分析仪进行细菌的鉴定及药敏试验,部分药敏试验采用K-B法.结果 91株MRSA中SCCmecⅡ型72株,占79.1％,SCCmecⅢ型16株,占17.6％,未分型3株,占3.3％,未见SCCmec Ⅰ型及SCCmecⅣ型;ICU中MRSA所占比例最多,为SCCmecⅡ型51.4％、SCCmecⅢ型37.5％,2种SCCmec基因型的MRSA对万古霉素、磺胺甲噁唑/甲氧苄啶、利奈唑胺、喹奴普汀/达福普汀的耐药率为0,对氯霉素的耐药率分别为11.1％和12.5％,对利福平的耐药率分别为8.3％和37.5％,其余均呈高水平耐药,2种SCCmec基因型的MRSA均表现为多药耐药.结论 临床分离的MRSA以SCCmecⅡ型为主,且对抗菌药物呈多药耐药.     

血流感染金黄色葡萄球菌分子特征及毒力基因分析

目的了解新疆军区总医院血流感染金黄色葡萄球菌临床分离株的分子特征,检测毒力基因携带情况及其对临床常用抗菌药物的耐药性。方法收集2012-2016年新疆军区总医院不同血流感染患者分离的53株金黄色葡萄球菌,应用聚合酶链式反应(Polymerase Chain Reaction,PCR)鉴定甲氧西林耐药性;应用SCCmec分型、spa分型、多位点序列分型(multilocus sequence typing,MLST)等分子分型方法对金黄色葡萄球菌进行分析,PCR检测pvl等21种毒力基因,分析不同克隆毒力基因携带情况,观察菌株对临床常用抗菌药物的耐药性。结果 53株金黄色葡萄球菌中30株为耐甲氧西林金黄色葡萄球菌(methicillin-resistant Staphylococcus aureus,MRSA),23株为甲氧西林敏感金黄色葡萄球菌(methicillin-susceptible Staphylococcus aureus,MSSA)。30株MRSA菌分为4种ST型和4种spa型,3种SCCmec型,优势流行克隆为MRSA-ST239-t030-SCCmecⅢ占90.0%(27/30)同时鉴定出3株社区获得性MRSA。23株MSSA鉴定出10种ST型、14种spa型,主要流行克隆为ST22-t309,检出4株动物源性的克隆ST398。所有菌株中均检测到hla及hld两种溶血素基因,ST239克隆均携带有sea,see,hla,hld以及hlg-2基因,少量菌株还携带有pvl,sed等基因。ST22克隆则携带有包括pvl,seg等8种毒力基因。MRSA菌株对常用抗菌药物呈现高度耐药,MSSA菌株对青霉素、红霉素的耐药率分别为91.3%和69.6%,对其他抗菌药物敏感。结论引起新疆军区总医院血流感染主要MRSA克隆为MRSAST239-t030-SCCmecⅢ,对抗菌药物耐药程度较高;主要MSSA克隆为ST22-t309,携带较多毒力基因,具有高毒力。     

临床分离金黄色葡萄球菌的耐药特点和MRSA分子分型

目的研究耐甲氧西林金黄色葡萄球菌(MRSA)的耐药性及其基因分型。方法收集某院2014年1月—2015年11月检出的非重复金黄色葡萄球菌967株,检测其药敏结果及mecA抗性基因、杀白细胞素(PVL)基因;MRSA菌株经多重PCR进行葡萄球菌盒式染色体mec(SCCmec)分型、多位点序列分型(MLST)、金黄色葡萄球菌蛋白A基因(spa)分型、金黄色葡萄球菌附属因子调节子(agr)分型。结果 967株金黄色葡萄球菌共检出210株MRSA,MRSA检出率为21.72%;痰标本MRSA检出率高于皮肤软组织标本(68.09%vs 11.83%,P0.05);金黄色葡萄球菌中未发现对万古霉素和利奈唑胺耐药菌株,MRSA对庆大霉素、四环素、红霉素、克林霉素、左氧氟沙星、环丙沙星、莫西沙星、呋喃妥因、利福平的敏感率均低于MSSA,差异均有统计学意义(均P0.05);MRSA对复方磺胺甲口恶唑的敏感率高于MSSA,差异有统计学意义(P0.05)。皮肤软组织分离的MRSA对庆大霉素、左氧氟沙星、环丙沙星、莫西沙星、利福平的敏感率为86.90%~95.24%,而痰分离的MRSA仅为1.56%~15.63%。967株金黄色葡萄球菌检测出210株携带mecA基因,10株携带PVL基因,210株MRSA中有8株未分型,占3.81%。MLST主要以ST239(177株)为主;SCCmec分型主要以Ⅲ型(177株)为主;spa分型主要以t 030(177株)为主;agr分型主要以Ⅰ型(196株)为主。结论该院MRSA菌株主要流行克隆ST239-MRSA-SCCmecⅢ-t030,耐药形势严峻,应加强医院内耐药菌株的监测。     

天津地区皮肤软组织感染分离的MRSA菌株基因分型和毒力基因及耐药性

目的 分析本地区皮肤软组织感染分离的耐甲氧西林金黄色葡萄球菌(MRSA)菌株的基因分型、毒力基因及耐药性情况。方法 收集2019年1月-2020年12月天津市第五中心医院就诊的204例皮肤及软组织感染患者皮损分泌物,分离出MRSA菌株,所有菌株均为非重复菌株;分析MRSA菌株葡萄球菌盒式染体色mec(SCCmec)、葡萄球菌蛋白A基因(spa)基因分型及杀白细胞素(PVL)基因携带情况,并评估其与耐药性的关系。结果 204例皮肤及软组织感染患者皮损分泌物分离出82株金黄色葡萄球菌,其中MRSA有44株(53.66%),最流行的SCCmec分型为Ⅲ型,占比84.09%,最流行的spa分型为t030,占比84.09%,有5株扩增出编码毒力因子PVL基因(11.36%)。44株MRSA对万古霉素及磺胺甲噁唑/甲氧苄啶耐药性均为0,对青霉素全部耐药,不同SCCmec及spa基因分型对红霉素、头孢唑林、克林霉素、左氧氟沙星均具有较高耐药性,不同spa基因分型对克林霉素、左氧氟沙星耐药性有统计学差异(P<0.05)。PVL基因阳性对氯霉素、庆大霉素、四环素的耐药性高于PVL基因阴性(P<...     

社区分离金黄色葡萄球菌在健康人群中的分布及其分子生物学特点

目的 调查医科大学学生鼻腔中金黄色葡萄球菌(金葡菌)的定植状况,解析鼻腔定植社区型甲氧两林耐药性金葡菌(MRSA)克隆的分子生物学特点.方法 以无菌棉签从调查对象鼻腔中收集定植菌,鉴定出甲氧西林敏感性金葡菌(MSSA)和MRSA;多重PCR法分型MRSA携带的SCCmec基因岛;PCR测定pvl、seh、tsst1等毒素基因在菌株中的分布;脉冲场凝胶电泳(PFGE)检测MRSA菌株的脉冲场型.结果 2009年977名学生488份样本中鉴定出葡萄球菌,其中凝固酶阴性葡萄球菌(CoNS)和金葡菌分别为364份和124份,MRSA在金葡菌中所占比例为3.4%.2010年调查显示,657名学生中有310份样本鉴定为葡萄球菌属,其中CoNS为195份,金葡菌115份,MRSA在金葡菌中所占比例为7.7%.金葡菌在所有葡萄球菌属中所占比例为29.9%,而MRSA在金葡菌中所占比例为5.1%.MRSA菌株中共鉴定出5种SCCmec基因岛型,其中Ⅳa型最多(10株),为优势SCCmec基因岛类型.PFGE共有11种图谱型,7种(A～G)脉冲场型.10株MRSA均为pvl阳性.结论 1株起源于社区,基因型为Ⅳa SCCmec-pulsotype A且携带pvl毒素基因的特定MRSA克隆在健康大学生中传播.

Abstract：

Objective To investigate the nasal colonization of Staphylococcus (S.) aureus strains among medical university students in Shenyang and to study the molecular epidemiological characteristics of methicillin resistant S. aureus (MRSA) strains. Methods Sterilized nasal swabs were used to collect nasal bacteria from both nares of the students. Nasal specimens were further identified as S. aureus strains, sensitive or resistant to methicillin through a series of tests. Molecular related methods including staphylococcal cassette chromosome mec (SCCmec) typing, pulsed- field gel electrophoresis (PFGE) , coagulase isotyping and minimum inhibitory concentration (MIC) determination etc. were used to characterize the isolates. Prevalence of the panton-valentine leukocidin (pvl) genes (lukS and F-PV) among the isolates was also assessed. Results Staphylococci were found in 488 specimens from 977 participants through the surveillance program, conducted in 2009. Of the 488 specimens being tested, 364 were identified as coagulase-negative staphylococci (CoNS) and 124 as S. aureus. MRSA strain among the S. aureus isolates was accounted for 3.4%. In the surveillance program conducted in 2010, staphylococci grew in 310 specimens fiom 657 participants. Of the 310 specimens tested, 195 were identified as CoNS and 115 as S. aureus. The percentage of MRSA strains among the S. aureus isolates was 7.7%. In total, 239 students carried S.aureus, and the percentage of MRSA carriers among the total specimens tested in this study was 5.1%.Most of the MRSA strains could be classified into one of the five types of SCCmec elements. Type Ⅳ a SCCmec strains were most frequent seen overall (10 isolates). A total of 11 pulsotypes were identified among the MRSA strains and were classified into 7 major groups (A to G) by the mutual correlations of their banding patterns. Ten MRSA strains were identified as pvl positive strains. Conclusion An MRSA clone (Ⅳ a SCCmec pulsotype A) carrying pvl toxin gene was found to be prevalent in the nares of the healthy university students.     

Molecular characterization of methicillin-resistant Staphylococcus aureus spread by neonates transferred from primary obstetrics clinics to a tertiary care hospital in Korea.

OBJECTIVE: To investigate the characteristics and origins of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from neonatal patients admitted to a tertiary care hospital from local and primary care obstetrics clinics. DESIGN: Molecular typing study. SETTING: A 1,278-bed tertiary care hospital (Samsung Medical Center) and 2 primary obstetrics clinics in Seoul, Korea. PATIENTS: The genotypic characteristics of 12 MRSA samples isolated from 11 neonatal patients transferred from 2 primary care obstetrics clinics to a tertiary care hospital were investigated by means of multilocus sequence typing, spa (staphylococcal protein A) typing, and SCCmec typing. Ten MRSA strains isolated from workers and environments in the associated obstetrics clinics were also investigated. RESULTS: Although the antibiograms of isolates from 2 obstetrics clinics differed, no strain showed multidrug resistance to antimicrobials. Multilocus sequence typing analysis showed that all 22 MRSA isolates analyzed in this study had sequence type 1 (with the allelic profile 1-1-1-1-1-1-1), sequence type 493 (62-1-1-1-1-1-1), or a novel sequence type (25-1-1-1-1-1-1) and that all belonged to a single clonal complex (clonal complex 1). Moreover, they all contained SCCmec type IVA and the identical spa type (UJEBKBP). These genotypic characteristics are similar to those of typical community-associated MRSA strains rather than the hospital-acquired MRSA strains common in Korea. CONCLUSION: The findings of this study suggest that community-acquired MRSA strains can spread in primary care clinics and be imported into tertiary care settings.     

ICU患者分离金黄色葡萄球菌的耐药性及分子流行病学特征

目的了解某院重症监护病房（ICU）金黄色葡萄球菌的耐药特点及分子流行病学特征。方法收集2014年1—12月该院ICU分离的金黄色葡萄球菌,进行细菌鉴定及药物敏感性试验,采用金黄色葡萄球菌A蛋白(spa)分型及多位点序列分型(MLST)方法进行分型。结果160株金黄色葡萄球菌中耐甲氧西林金黄色葡萄球菌（MRSA）120株（占75.00%）。MRSA对红霉素、克林霉素、左氧氟沙星的耐药率均＞80%;MSSA对头孢唑林敏感,对红霉素、克林霉素、左氧氟沙星的耐药率分别为62.50%、35.00%、10.00%。spa分型和MLST结果显示,120株MRSA主要为ST239 t030、ST239 t037、ST5 t2460 3种型别,其中ST239 t030（105株,87.50%）为主要流行菌株,8个ICU均有检出;MSSA存在较多型别,ST59 t437仅在神经内科(8株)和消化科（2株）检出,ST6 t701、ST398 t3625、ST398 t1793和ST121 t2092分别仅在神经内科（7株）、麻醉科（5株）、神经外科（4株）和心外科（4株）检出。结论该院ICU MRSA分离率较高,以ST239 t030克隆株为主,存在医院内流行;不同型别MSSA在各科室内存在流行趋势。     

Antimicrobial susceptibility testing and genotypic characterization of Staphylococcus aureus from food and food animals

Staphylococcus aureus is commonly present in humans and animals. The aim of this study was to investigate antimicrobial resistance and genetic characteristics of S. aureus from food and food animals in Shaanxi Province in China. A total of 332 nasal swabs, breast skin swabs, raw milk, and pork samples were collected from local pig, dairy farms, or local grocery stores and screened for the presence of S. aureus. S. aureus isolates were characterized using antimicrobial susceptibility, pulsed-field gel electrophoresis (PFGE) analysis, and polymerase chain reaction for detecting pvl and mecA genes. Methicillin-resistant S. aureus (MRSA) strains were additionally tested for SCCmec type and exfoliative toxin genes. The prevalence of S. aureus was 30.6% in pig nasal swabs, 32.5% in pork, 25.7% in cow nasal swabs, 30.8% in cow breast skin swabs, and 29.3% in milk samples. Resistances were common among isolates tested against erythromycin (65.7%), tetracycline (65.7%), ciprofloxacin (52.7%), followed by gentamicin (36.7%), chloramphenicol (23.1%), cefoxitin (8.3%), and oxacillin (7.7%), but no isolate was resistant to vancomycin, amikacin, or cefoperazone. pvl gene was found in the isolates from all types of samples except from cow nasal swabs. Fourteen isolates from pig nasal swabs contained mecA gene and were considered as MRSA. PFGE analysis showed that nasal isolates differed from food isolates, but isolates from the same animal source appeared to cluster closely. The PFGE patterns of MRSA isolates were different from other S. aureus isolates from pig nasal cavity even though they were from the same source. All the MRSA isolates belonged to SCCmec type IV(b). No isolates contained exfoliative toxin genes. These findings indicated that S. aureus, including multidrug-resistant S. aureus, are widely spread in food animals and animal-derived foods in Shaanxi Province, China. MRSA isolates from pigs may pose potential health risks for workers in swine farms and the community at large.     

An outbreak of post-partum breast abscesses in Mumbai, India caused by ST22-MRSA-IV: genetic characteristics and epidemiological implications

SUMMARY A cluster of methicillin-resistant Staphylococcus aureus (MRSA) breast abscesses in women who had given birth at a hospital in Mumbai, India was investigated retrospectively. Nineteen of 20 cases were caused by a single clone: pvl-positive, spa type 648 (Ridom t852), ccrB:dru subtype 3:0, ST22-MRSA-IV. Despite the presence of pvl and SCCmec type IV, which are common genetic markers in community-associated MRSA, this outbreak was caused by a healthcare-associated, community-onset MRSA that was common in the hospital environment. Thus, infection control practices may have an important role in limiting the spread of this virulent clone.     

中国15个地区分离的耐甲氧西林金黄色葡萄球菌基因分型研究

目的 研究中国2006年耐甲氧西林金黄色葡萄球菌(MRSA)流行株的来源和遗传背景.方法 收集2006年1-12月15个地区17家医院连续分离的非重复MRSA 302株,通过多重PCR对MRSA进行染色体mec(SCCmec)分型,葡萄球菌A蛋白(Spa)分型和多位点序列分型(MLST).结果 SCCmec分型Ⅲ型为76.8%,不能分型为7.9%.从广州地区分离株中发现2株Ⅳ型,Ⅱ型为14.6%;而大连地区分离株中Ⅱ型为75.0%,与其他地区菌株分型的差异存在统计学意义(P<0.005).MLST共有4种分型,其中序列分型(ST)239(46.7%)、ST5(44.4%)、ST59(6.7%)、ST88(2.2%).Spa分型共有14种,其中t30(52.6%)、t37(27.2%)、t2(12.9%)、t632(2.3%)、t437(1.3%)和t570、t601(各0.7%)及t377、t459、t796、t899、t1152、t2649(各0.3%),未分型占0.3%.未检出pvl以基因.结论 调查的15个地区MRSA主要克隆株为ST239-MRSA-SCCmecⅢ-t30和ST5-MRSA-SCCmecⅡ-t2,具有独特的地理分布.     

Rapid increase of genetically diverse methicillin-resistant Staphylococcus aureus, Copenhagen, Denmark

In Copenhagen, methicillin-resistant Staphylococcus aureus (MRSA) accounted for <15 isolates per year during 1980-2002. However, since 2003 an epidemic increase has been observed, with 33 MRSA cases in 2003 and 110 in 2004. We analyzed these 143 cases epidemiologically and characterized isolates by pulsed-field gel electrophoresis, Staphylococcus protein A (spa) typing, multilocus sequence typing, staphylococcal chromosome cassette (SCC) mec typing, and detection of Panton-Valentine leukocidin (PVL) genes. Seventy-one percent of cases were community-onset MRSA (CO-MRSA); of these, 36% had no identified risk factors. We identified 29 spa types (t) and 16 sequence types (STs) belonging to 8 clonal complexes and 3 ST singletons. The most common clonal types were t024/ST8-IV, t019/ST30-IV, t044/ST80-IV, and t008/ST8-IV (USA300). A total of 86% of isolates harbored SCCmec IV, and 44% had PVL. Skin and soft tissue infections dominated. CO-MRSA with diverse genetic backgrounds is rapidly emerging in a low MRSA prevalence area.