携带Panton-Valentine杀白细胞素基因金黄色葡萄球菌所致感染类型研究

目的 研究携带Panton-Valentine杀白细胞素（Panton-Valentine leukocidin，PVL）基因金黄色葡萄球菌所致感染类型。方法利用多重PCR检测金黄色葡萄球菌临床分离株的PVL基因，应用多位点基因序列分型（multilocus sequence typing，MLST）技术对PVL基因阳性的菌株进行序列分型，耐甲氧西林金黄色葡萄球菌（methicillin-resistant Staphylococcus aureus，MRSA）的SCCmec基因分型采用多重PCR。结果 26株携带PVL基因的金黄色葡萄球菌有13株为ST88，5株为ST239，5株为ST398，ST25、ST30和ST59各1株。20株为医院获得株，主要引起肺部感染和术后伤口化脓性感染；6株为社区感染株，主要引起软组织化脓性感染。7株MSSA全部为ST88，主要引起化脓性感染。而19株MRSA分布在6种ST型中，主要有ST88-SCCmecⅢA、ST239-SCCmecⅢ、ST398．SCCmecⅣ和ST398-SCCmecⅢ。26株菌株分布于14个病区，在产科发生过携带PVL基因的ST88．SCCmecⅢA．MRSA克隆株的播散。结论 本院分离的携带PVL基因的金黄色葡萄球菌的序列型主要为ST88、ST239和ST398，既可造成医院感染也可造成社区感染且可能引起克隆株的播散。     

重庆地区金黄色葡萄球菌临床株的分子型别与耐药性检测

目的了解重庆地区金黄色葡萄球菌临床菌株的分子型别及其对常用抗菌药物的耐药情况,为防控该地区金葡菌感染提供理论依据。方法收集2013年6月至2014年12月期间重庆地区西南医院临床分离的110株金黄色葡萄球菌,利用特征性基因扩增区分甲氧西林敏感金黄色葡萄球菌(MSSA)和耐甲氧西林金黄色葡萄球菌(MRSA),再采用多位点序列分型(MLST)、spa分型、SCCmec分型、agr分型等方法检测金葡菌的型别,采用PCR检测pvl毒力基因,药敏试验分析菌株对苯唑西林、万古霉素、四环素等13种临床常用抗菌药物的耐药性,分析菌株的耐药谱。结果 110株金葡菌中有59株为MRSA,51株为MSSA,MRSA阳性率为53.6%。59株MRSA分为11种spa型和8种ST型,优势流行克隆为ST239-MRSA-Ⅲ(57.6%,34/59),pvl毒力基因检出率为23.7%(14/59)。51株MSSA分为27种spa型和18种ST型,agrI型占68.6%(35/51),pvl检出率为7.8%(4/51)。药敏结果显示59株MRSA均为多重耐药(MDR)菌株,51株MSSA中有24株为MDR菌株。结论重庆地区流行的MRSA以ST239-MRSA-Ⅲ为主,而MSSA表现出较高遗传多样性,发现ST121等高毒力、高耐药性菌株,值得高度重视。     

新的细胞壁锚定蛋白编码基因sasX在金黄色葡萄球菌中的分布

目的 研究细胞壁锚定蛋白编码基因sasX在金黄色葡萄球菌中的分布及对细菌耐药性的影响.方法 随机收集上海华山医院2004、2007和2010年从金黄色葡萄球菌感染的住院患者标本中分离鉴定的金黄色葡萄球菌共300株,收集同时期社区健康人群的鼻咽拭子分离鼻腔内定植的金黄色葡萄球菌170株.按照国际通用的MLST以及葡萄球菌A蛋白序列分析(spa typing)方法进行克隆株的鉴定分析.通过苯唑西林MIC值测定方法对MRSA进行检测.采用PCR结合测序方法对金黄色葡萄球菌携带sasX基因情况进行分析,采用纸片琼脂扩散法药敏试验分析临床sasX阳性和sasX阴性金黄色葡萄球菌对抗菌药物的耐药性.结果 300株从金黄色葡萄球菌感染的住院患者标本中分离到的致病性金黄色葡萄球菌克隆分型以ST239(110株,36.7％)和ST5(122株,40.7％)为主.2004至2010年,sasX基因在致病性的金黄色葡萄球菌中的阳性率从17％上升至39％,sasX基因在健康人鼻腔内分离的金黄色葡萄球菌中阳性率平均为0.59％.ST239中sasX的阳性率从47.2％上升至83.8％.携带sasX基因的MRSA百分率从26.4％上升至50.8％,携带sasX基因的MSSA的比率只约占10％.sasX基因阳性组对部分目前临床常用的抗菌药物的耐药性高于sasX基因阴性组.结论 sasX基因主要存在于医院环境内致病性的金黄色葡萄球菌中,SasX可能是金黄色葡萄球菌在医院环境内持续感染毒力因子之一,sasX基因的存在与细菌的耐药有关.     

金黄色葡萄球菌的药敏表型和耐甲氧西林金黄色葡萄球菌的SCCmec基因分型

目的研究从临床标本中分离的金黄色葡萄球菌(SA)的耐药性、耐甲氧西林金黄色葡萄球菌(MRSA)的发生率及其葡萄球菌盒式染体色mec(SCCmec)基因分型。方法采用纸片琼脂扩散法进行SA耐药性检测及MRSA测定,应用多重聚合酶链反应(PCR)进行SCCmec各基因型及PV杀白细胞素(PVL)基因型的检测。结果 102株SA中检出39株MRSA,检出率为38.2%(39/102)。甲氧西林敏感金黄色葡萄球菌(MSSA)对克林霉素、复方磺胺甲口恶唑、四环素3种抗菌药物耐药率较高,分别为39.7%、31.7%、22.2%;对庆大霉素及喹诺酮类耐药率较低,为6.3%~14.3%。而MRSA对克林霉素、β-内酰胺类抗菌药物100%耐药,对其他药物表现为多重耐药。未检出万古霉素耐药菌株。MRSA菌株的SCCmec基因型以SCCmecⅢ型为主,占71.2%,SCCmecⅣa占10.3%,未检测出PVL基因。结论临床分离的SA中,MRSA耐药率较MSSA高且表现为多重耐药,其SCCmec基因分型主要表现为SCCmecⅢ型,其次是SCCmecⅣa。     

金黄色葡萄球菌的药敏表型和耐甲氧西林金黄色葡萄球菌的SCCmec基因分型

目的研究从临床标本中分离的金黄色葡萄球菌（SA）的耐药性、耐甲氧西林金黄色葡萄球菌（MRSA）的发生率及其葡萄球菌盒式染体色mec（SCCmec）基因分型。方法采用纸片琼脂扩散法进行SA耐药性检测及MRSA测定,应用多重聚合酶链反应（PCR）进行SCCmec各基因型及PV杀白细胞素（PVL）基因型的检测。结果 102株SA中检出39株MRSA,检出率为38.2%（39/102）。甲氧西林敏感金黄色葡萄球菌（MSSA）对克林霉素、复方磺胺甲口恶唑、四环素3种抗菌药物耐药率较高,分别为39.7%、31.7%、22.2%;对庆大霉素及喹诺酮类耐药率较低,为6.3%~14.3%。而MRSA对克林霉素、β-内酰胺类抗菌药物100%耐药,对其他药物表现为多重耐药。未检出万古霉素耐药菌株。MRSA菌株的SCCmec基因型以SCCmecⅢ型为主,占71.2%,SCCmecⅣa占10.3%,未检测出PVL基因。结论临床分离的SA中,MRSA耐药率较MSSA高且表现为多重耐药,其SCCmec基因分型主要表现为SCCmecⅢ型,其次是SCCmecⅣa。     

50株临床分离金黄色葡萄球菌分子流行病学及药物敏感性分析

目的研究北京电力医院2009年10月至2010年3月连续分离的金葡菌的分子流行病学特征及药物敏感性状况。方法收集在此期间临床连续分离的金葡菌,采用多位点序列分型(MLST)和葡萄球菌蛋白A基因(spa)分型技术进行分子生物学分型,同时进行Panton-Valentine(PVL)毒素基因检测,并对其中的33株甲氧西林耐药金葡菌(MRSA)进行SCCmec分型;采用琼脂稀释法作MRSA对14种抗菌药物的药敏试验。结果 50株金葡菌中,检出MRSA33株,占66.0%,其中1株为社区获得性(CA)-MRSA。MRSA有6种克隆型,其中ST239-t030-Ⅲ型占绝对优势,并且发现了国内罕见的新克隆型(ST239-t2270-Ⅲ)的传播;相比较,MSSA分子分型则呈散在分布。药敏试验结果显示,糖肽类抗生素及替加环素对MRSA的抗菌作用最强。CA-MRSA携带PVL毒素基因,其耐药谱与医院获得性(HA)-MRSA有较大差异。结论相比于MSSA,MRSA的克隆型别相对集中,提示MRSA更容易引起医院内的传播。MRSA以ST239-t030-Ⅲ为最常见型别,与我国总体趋势一致。     

杭州市富阳区甲氧西林耐药金黄色葡萄球菌基因分型研究

目的对杭州市富阳区临床分离的甲氧西林耐药金黄色葡萄球菌(MRSA)进行基因分型并分析其流行现状。方法收集临床送检标本中分离出的金黄色葡萄球菌,采用全自动细菌鉴定/药敏系统进行药敏试验,对所有MRSA菌株进行多位点序列分型(MLST)、葡萄球菌蛋白A基因(spa)分型和葡萄球菌盒式染色体(SCCmec)分型,同时应用脉冲场凝胶电泳(PFGE)进行同源性分析。结果分离到金黄色葡萄球菌121株,其中MRSA 22株,占18.2%。药敏试验显示MRSA对β-内酰胺类、红霉素全耐药,对左氧氟沙星、环丙沙星的耐药率85.0%,未发现万古霉素、利奈唑胺耐药株。SCCmec、spa、MLST分型表明以ST5-t311-SCCmecⅡ基因型为主,部分菌株之间同源性程度高。结论杭州市富阳区MRSA的检出率目前还处于相对较低的水平,流行克隆以ST5-t311-SCCmecⅡ型为主。     

某院血流感染金黄色葡萄球菌临床分布特点、耐药性及基因分型研究

目的分析该院血流感染金黄色葡萄球菌的临床分布特点、耐药性及基因分型。方法通过全自动细菌鉴定仪对该院2010年1月至2017年1月分离出的102株血流感染金黄色葡萄球菌行细菌鉴定及药敏试验,同时经PCR测定耐药基因分型。结果临床分布特点:年龄分布以70~80岁最多,占29.41%;其次为50~60岁,占15.69%。科室分布:重症监护病房(ICU)最多,占29.41%;其次为血液透析室,占21.57%。耐药情况:对青霉素耐药率最高,占94.12%;其次为克林霉素,占66.67%;对万古霉素、替加环素、替考拉宁、利奈唑胺均100.00%敏感;耐甲氧西林金黄色葡萄球菌(MRSA)对青霉素、克林霉素、红霉素、庆大霉素、左氧氟沙星、四环素、利福平、环丙沙星、氨苄西林/舒巴坦的耐药率均显著高于甲氧西林敏感金黄色葡萄球菌(MSSA)(P0.05)。基因分型:erm基因携带率100.00%;MRSA中ermA基因12株,ermA+ermC基因28株;MSSA中ermB基因38株,ermC基因24株;诱导型耐药株中ermC基因占77.27%。结论金黄色葡萄球菌血流感染患者以老年(特别是高龄)人群比较常见,ICU较常见;MRSA检出率较高,金黄色葡萄球菌中erm基因携带率高,MRSA中以ermA基因常见,MSSA中ermB基因居多,MRSA大部分对多种抗菌药物耐药,建议选择万古霉素、替加环素等敏感度高的抗菌药物治疗。     

鄂尔多斯地区蒙古族人群耐甲氧西林金黄色葡萄球菌基因分型

目的探讨鄂尔多斯地区蒙古族人群耐甲氧西林金黄色葡萄球菌(MRSA)的分子流行病学特点,明确本地区MRSA基因型别及其分布规律。方法收集2009年1月至2011年8月临床分离的MRSA菌株54株。应用多重聚合酶链反应(PCR)对MRSA菌株进行葡萄球菌染色体mec(SCCmec)基因分型、杀白细胞毒素(PVL)毒力基因(pvl)和多位点序列分型(MLST)检测。结果 MRSA菌株的SCCmecⅠ~Ⅴ基因分型分别占0.00%、50.00%、46.30%、1.85%和1.85%;检测出1株pvl基因阳性;24株MRSA菌株MLST分型显示,ST239 13株(54.17%),ST59株(37.50%),ST5 9和ST7各1株(4.17%)。结论鄂尔多斯地区蒙古族人群MRSA菌株以SCCmecⅡ型和SCCmecⅢ型为主。     

金黄色葡萄球菌耐药基因分析及多位点序列分子分型

目的对临床来源金黄色葡萄球菌(金葡菌)进行分子分型及溯源,研究耐药基因与克隆复合体(CC)关系。方法检测94株金葡菌中的耐甲氧西林金葡菌(MRSA)并分型,测定氨基糖苷类耐药基因[aac(6')/aph(2')、aph(3')-Ⅲ、ant(4',4')]、大环内酯类耐药基因(ermA、ermC、msrA)、四环素类耐药基因(tetM、tetk)共8个耐药基因;用多位点序列分子分型(MLST)进行克隆分析。结果 94株菌株中共检出MRSA菌株36株,其中,医源MRSA(HA-MRSA)29株,包括Ⅲ型28株,Ⅰ型1株;社区源MRSA(CA-MRSA)7株,包括V型6株,Ⅳd型1株。94株菌株中,耐药基因aac(6')/aph(2')、aph(3')-Ⅲ、ant(4',4')、ermA、ermC、msrA、tetM、tetk的携带率分别为55.3%、58.5%、26.6%、37.2%、34.0%、19.1%、37.2%、25.5%;共84株菌株耐药基因阳性,共形成35种耐药基因谱;含3种以上耐药基因的菌株占48.9%(46/94)。MLST分型共得到27个ST型,6个同源复合体;有3个重要同源复合体CC239、CC630、CC5及1个重要ST398型。HA-MRSA均属于CC239,而多数CAMRSA属于CC630;HA-MRSA耐药基因携带率与CA-MRSA及所有甲氧西林敏感金葡菌(MSSA)携带率差异有统计学意义(P0.01)。CC239克隆与所有其他克隆菌株耐药基因的携带率差异有统计学意义(P0.01)。结论引起感染的MRSA主要是HA-MRSA-Ⅲ,其次为CA-MRSA-Ⅴ。CC630是国际上新出现的克隆;ST398主要是起源于人而非动物。MRSA主要存在于几类特定克隆中,主要来源于相同克隆的MSSA;金葡菌获得及携带耐药基因主要与CC克隆有关,推测此类复合体中含有相关分子构型,有利于耐药基因如SCCmec插入。     

Different clonal complexes of methicillin-resistant Staphylococcus aureus are disseminated in the Euregio Meuse-Rhine region

The Euregio Meuse-Rhine (EMR) is formed by the border regions of Belgium, Germany, and The Netherlands. Cross-border health care requires infection control measures, in particular since the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) differs among the three countries. To investigate the dissemination of MRSA in the EMR, 152 MRSA isolates were characterized by pulsed-field gel electrophoresis (PFGE), SCCmec typing, and multilocus sequence typing. PFGE revealed major clonal groups A, G, L, and Q, suggesting dissemination of MRSA in the EMR. Group A harbored mainly SCCmec type III and sequence types (STs) 239 and 241. The majority of the strains from group G harbored SCCmec type I and ST8 and ST247, whereas most strains from group L carried either SCCmec type IV or type I. Within group L, ST8 and ST228 were found, belonging to clonal complexes 8 and 5, respectively. Most strains from group Q included SCCmec type II and were sequence typed as ST225. Both ST225-MRSA-II and ST241-MRSA-III were novel findings in Germany. In addition, the SCCmec type of two isolates has not been described previously. One strain was classified as SCCmec type III but harbored the pls gene and the dcs region. Another strain was characterized as SCCmec type IV but lacked the dcs region. In addition, one isolate harbored both SCCmec type V and Panton-Valentine leukocidin. Finally, the SCCmec type of the strains was found to be correlated with the antibiotic susceptibility pattern.     

Genotypic diversity of methicillin-resistant Staphylococcus aureus isolates in Korean hospitals

Ninety-six methicillin-resistant Staphylococcus aureus (MRSA) isolates from eight Korean hospitals were analyzed by multilocus sequence typing, SCCmec typing, and spa typing. The predominant genotype was ST5-MRSA-II of clonal complex 5, which was found in 36 isolates from six hospitals, but ST239-MRSA-III was also common. Overall, results showed a notable genotypic diversity of MRSA strains circulating in Korean hospitals.     

Related clones containing SCCmec type IV predominate among clinically significant Staphylococcus epidermidis isolates

SCCmec is a mobile genetic element that carries the gene (mecA) mediating methicillin resistance in staphylococci. For Staphylococcus aureus, four SCCmec types have been described, one (type IV) of which has been associated with newly identified community-acquired methicillin-resistant S. aureus. However, the distribution of SCCmec types among S. epidermidis is not known. SCCmec typing of a collection of 44 methicillin-resistant Staphylococcus epidermidis (MRSE) isolates recovered between 1973 and 1983 from the blood of patients with prosthetic valve endocarditis (PVE) was performed by PCR amplification of key genetic elements (mecA, mecI, IS1272, and ccrAB). Of the 44 isolates, 1 (2%) harbored SCCmec type I, 15 (34%) harbored type II, 12 (28%) harbored type III, and 16 (36%) harbored type IV. The complete nucleotide sequence of SCCmec type IV was determined for 16 isolates and found to be identical in size (24 kb) and 98% homologous to DNA sequences published for S. aureus. Type IV SCCmec was also common (5 of 10 isolates) among a geographically dispersed collection of 10 recent (1998 to 2001) S. epidermidis bloodstream isolates. Multilocus sequence typing (MLST) (using the same seven genes presently employed for S. aureus MLST) of these MRSE isolates and of 10 additional recent geographically dispersed methicillin-susceptible isolates demonstrated that all 16 PVE isolates and 2 of 5 recent isolates harboring type IV SCCmec were in three related clonal groups. All three MSSE PVE isolates recovered from patients between 1976 and 1979 were in the same clonal groups as type IV SCCmec MRSE isolates. These data support the hypothesis of intra- and interspecies transfer of type IV SCCmec and suggest that there are clonal associations in S. epidermidis that correlate with SCCmec type.     

Molecular typing of methicillin-resistant staphylococci isolated from cats and dogs

OBJECTIVES: Methicillin-resistant staphylococci (MRS) isolates from healthy and diseased cats and dogs were characterized by staphylococcal cassette chromosome mec (SCCmec), multilocus sequence typing (MLST) and cassette chromosome recombinase gene (ccrAB) sequencing. METHODS: PCR-directed SCCmec typing was carried out for all MRS isolates and two Staphylococcus aureus and two Staphylococcus epidermidis strains were analysed by MLST. Strains belonging to SCCmec type III and IV were sequenced for their ccrAB gene of allotypes 3 and 2, respectively. RESULTS: Five types of SCCmec, types I, III, IV, IV (paediatric) and V SCCmec, were found. The S. aureus strains belonged to sequence type (ST) 239 and the two S. epidermidis belonged to ST43 and ST60 respectively. High sequence conservation was observed for the ccrAB gene of allotypes 2 and 3. CONCLUSIONS: MRS isolates from cats and dogs demonstrate a similar diversity of SCCmec types to those found in human staphylococci and ST239-MRSA-III, a widely dispersed strain in human hospitals, was identified in diseased dogs.     

DNA Microarray Profiling of a Diverse Collection of Nosocomial Methicillin-Resistant Staphylococcus aureus Isolates Assigns the Majority to the Correct Sequence Type and Staphylococcal Cassette Chromosome mec (SCCmec) Type and Results in the Subsequent Identification and Characterization of Novel SCCmec-SCCM1 Composite Islands

One hundred seventy-five isolates representative of methicillin-resistant Staphylococcus aureus (MRSA) clones that predominated in Irish hospitals between 1971 and 2004 and that previously underwent multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing were characterized by spa typing (175 isolates) and DNA microarray profiling (107 isolates). The isolates belonged to 26 sequence type (ST)-SCCmec types and subtypes and 35 spa types. The array assigned all isolates to the correct MLST clonal complex (CC), and 94% (100/107) were assigned an ST, with 98% (98/100) correlating with MLST. The array assigned all isolates to the correct SCCmec type, but subtyping of only some SCCmec elements was possible. Additional SCCmec/SCC genes or DNA sequence variation not detected by SCCmec typing was detected by array profiling, including the SCC-fusidic acid resistance determinant Q6GD50/fusC. Novel SCCmec/SCC composite islands (CIs) were detected among CC8 isolates and comprised SCCmec IIA-IIE, IVE, IVF, or IVg and a ccrAB4-SCC element with 99% DNA sequence identity to SCC(M1) from ST8/t024-MRSA, SCCmec VIII, and SCC-CI in Staphylococcus epidermidis. The array showed that the majority of isolates harbored one or more superantigen (94%; 100/107) and immune evasion cluster (91%; 97/107) genes. Apart from fusidic acid and trimethoprim resistance, the correlation between isolate antimicrobial resistance phenotype and the presence of specific resistance genes was ≥97%. Array profiling allowed high-throughput, accurate assignment of MRSA to CCs/STs and SCCmec types and provided further evidence of the diversity of SCCmec/SCC. In most cases, array profiling can accurately predict the resistance phenotype of an isolate.     

Molecular characterization of methicillin-resistant Staphylococcus aureus strains from pet animals and their relationship to human isolates

OBJECTIVES: Methicillin-resistant Staphylococcus aureus (MRSA) isolates from pet animals were characterized and compared with human isolates from clonal complexes most prevalent in Central Europe. METHODS: S. aureus isolates were investigated for their in vitro susceptibility to antimicrobial agents by broth microdilution. Resistance genes and the Panton-Valentine leucocidin gene lukF-lukS were identified by PCR. All isolates were characterized by SmaI macrorestriction analysis and spa typing to assess their genomic relationships. Representative isolates were additionally analysed by multilocus sequence typing and PCR-directed SCCmec typing. RESULTS: All pet isolates carried the resistance genes mecA and erm(C) and proved to be resistant to beta-lactams and MLS(B) antibiotics. In addition, all isolates were resistant to fluoroquinolones. None of the pet isolates carried the Panton-Valentine leucocidin gene lukF-lukS. Macrorestriction analysis revealed that the pet MRSA isolates exhibited four closely related SmaI fragment patterns. Moreover, all isolates revealed spa type t032. Further analysis of representatives of the different PFGE types revealed the presence of multilocus sequence type ST22 in combination with a type IV SCCmec element. Thus, molecular typing results were similar for pet strains and human ST22 reference strains. CONCLUSIONS: Based on their strain characteristics, the MRSA isolates from pets investigated in this study closely resembled ST22 MRSA isolates which are widely disseminated in German hospitals. The results of this study indicate that cross-transmission of MRSA between pet animals and humans might have occurred.     

Epidemiology and susceptibilities of methicillin-resistant Staphylococcus aureus in Taiwan: emphasis on chlorhexidine susceptibility

Chlorhexidine is an antiseptic agent used for hand hygiene worldwide. To evaluate the susceptibility of methicillin-resistant Staphylococcus aureus (MRSA) to chlorhexidine, this study determined MICs of chlorhexidine and another 12 antimicrobial agents, carriage of the Panton–Valentine leukocidin, qacA/B, and smr genes, genetic relatedness by multilocus sequence typing (MLST), and staphylococcal cassette chromosome mec element type for 206 MRSA clinical isolates from the Taiwan Surveillance of Antimicrobial Resistance program III and IV (years 2002 and 2004) from 26 hospitals. Using MLST, we respectively identified 102 (49.5%), 68 (33.0%), 13 (6.3%), 5 (2.4%), 5 (2.4%), and 13 (6.3%) isolates as ST239, ST59, ST5, ST241, ST573, and other types. The MIC₅₀ and MIC₉₀ of chlorhexidine for all 206 isolates were 2 and 8 μg/mL, respectively. Seventy-three (35.4%) isolates carried qacA/B gene, but none carried smr. For the 72 (35.0%) MRSA isolates with chlorhexidine MIC ≥4 μg/mL, 53 were ST239 (49 of them carried qacA gene), 12 were ST5 (all carried qacB gene), 5 were ST241 (4 carried qacA gene), 1 was ST338 (and carried qacA gene), and 1 was ST573 (and carried qacA gene). Compared with other sequence-type MRSA isolates, ST239 MRSA isolates were the most resistant to both chlorhexidine and other antimicrobial agents. Methicillin-resistant S. aureus strains with disinfectant resistance qacA/B genes are common in Taiwan. High frequency of qacA/B genes among specific sequence types (ST239, ST5, and ST241) resulted in low susceptibility to chlorhexidine. Periodic surveillance of antiseptic susceptibility among MRSA isolates is important for the control of nosocomial hospital-acquired infections.