金黄色葡菌萄球耐药性监测

目的：监测成都市4家三级甲等医院临床分离的金黄色葡萄球菌（金葡菌）耐药性。方法：用琼脂稀释法测定11种抗菌药物对282株金葡菌的最低抑菌浓度（MIC）修正，并对菌株来源及科室分布进行分析。结果：282株金葡菌共筛出耐甲氧西林金葡菌（MRSA）94株，检出率为33.3％；甲氧西林 敏感金葡菌（MSSA）共188株。MSSA对青霉素和克拉霉素的耐药率分别为71.3％和54.8％，而对其抗菌药物敏感。MRSA对万古霉素、阿米卡星和利福平敏感性高（最强为万古霉素），而对其余多种抗菌药物耐药。MRSA来源最多为痰，其次为各种分泌物；科室分布依次为烧伤科、重症监护病房（ICU）、感染科等。结论：青霉素、大环内酯类药物不宜用于金葡菌感染。MRSA具有多重耐药性。MRSA感染首选糖肽类抗生素治疗。金葡菌是一种重要的病原菌，应长期进行耐药性监测，病室需做好消毒隔离。     

葡萄球菌耐药性的进展

金黄色葡萄球菌(下称金葡菌)广泛分布于自然界,很容易获得抗生素耐药性[1]。金葡菌对青霉素耐药出现于1994年,而对甲氧西林耐药出现于1961年,万古霉素是治疗耐甲氧西林金葡菌(MRSA)的首选药物,然而1996年日本发现对万古霉素中介的金葡菌(VISA),2002年和2004年美国又相继报道3例对万古霉素高度耐药的金葡菌(VRSA)。万古霉素耐     

647株金黄色葡萄球菌儿童分离株的分布和耐药性分析

目的了解儿童金黄色葡萄球菌(金葡菌)分离株耐药情况,为临床治疗用药提供依据。方法采用微生物检验报告系统统计分析金葡菌分离株中耐甲氧西林金葡菌(MRSA)比率,并分析MRSA和甲氧西林敏感金葡菌(MSSA)对主要抗菌药物的耐药性差异。结果共分离到647株金葡菌,其中MRSA194株,占29.98%。MRSA和MSSA对万古霉素、替加环素、替考拉宁、利奈唑胺、奎奴普丁-达福普汀和呋喃妥因均100%敏感,对甲氧苄啶-磺胺甲口恶唑、阿米卡星、青霉素的耐药率差异无统计学意义;MRSA对大多β内酰胺类药物及其含酶抑制剂、红霉素、四环素、利福平、庆大霉素、环丙沙星和左氧氟沙星的耐药率较MSSA高,差异有统计学意义。结论金葡菌儿童临床感染形势严峻,MRSA和MSSA对多种抗菌药物耐药率差异明显,儿童金葡菌相关性感染可根据病情及参考药敏结果选用敏感的抗菌药物治疗。     

痰标本中金黄色葡萄球菌的耐药性监测

目的回顾性分析痰标本中金葡菌的临床分布和耐药情况,为制订预防控制措施提供依据。方法对2009年1月至2012年9月临床分离的276株金葡菌进行分析,细菌鉴定采用VITEK 2 Compact全自动细菌培养鉴定仪,药敏试验结果按CLS1标准判断。结果耐甲氧西林金葡菌（MRSA）的检出率为79.0%（218/276）;临床分离的金葡菌主要分布为神经内科76株（27.5%）、ICU 70株（25.4%）、神经外科50）株（18.1%）、呼吸内科25株（9.1%）。金葡菌对万古霉素、替考拉宁和奎奴普丁-达福普汀的耐药率均〈0.5%;MRSA对甲氧苄啶-磺胺甲噁唑的耐药率低于甲氧西林敏感金葡菌（MSSA）;MRSA对其他大多数抗菌药物的耐药率高于MSSA。结论 MRSA的检出率和耐药率较高,临床应依据药敏试验结果合理选择抗菌药物。     

异质性万古霉素中介金黄色葡萄球菌的检测与分析

目的了解异质性万古霉素中介耐药金黄色葡萄球菌（h-VISA）在本院的感染情况，探讨不同最低抑菌浓度（MIC）的原代菌株间h-VISA检出率的差异。方法采用琼脂稀释法检测甲氧西林耐药的金黄色葡萄球菌（MRSA）对万古霉素的MIC值，用菌群分析法筛选h—VISA，计算h-VISA的检出率。结果45株MRSA中共检出h-VISA 7株，检出率为15．6％，原代菌对万古霉素MIC值越高，h-VISA检出率越高。结论本院存在h-VISA感染情况，应引起一定重视，系统地监测h-VISA的流行情况，对指导临床正确使用万古霉素，防止VISA和VRSA的出现有重要意义。     

2007—2010年临床分离菌分布及耐药性分析

目的了解新疆医科大学第一附属医院2007—2010年临床分离株的分布及抗菌药物的耐药情况。方法采用VITEK-2检测系统进行菌株鉴定和纸片扩散法(K-B法)对5 577株临床分离菌进行药敏试验。结果 5 577株临床分离株中革兰阳性菌占28.3%,革兰阴性菌占71.7%。甲氧西林耐药金葡菌(MRSA)和甲氧西林耐药凝固酶阴性葡萄球菌(MRCNS)的检出率分别为54.0%和80.1%。肺炎链球菌在成人患者和儿童患者中的检出率分别为41.9%和58.1%,成人患者和儿童患者中青霉素耐药株(PRSP)的检出率分别为22.2%和26.0%。未发现万古霉素耐药的屎肠球菌,未发现万古霉素耐药金葡菌(VRSA)或万古霉素中介金葡菌(VISA)。产ESBLs的大肠埃希菌、肺炎克雷伯菌和奇异变形杆菌的检出率分别为35.5%、40.3%和10.0%。肠杆菌科细菌对碳青霉烯类抗生素仍保持高度敏感性。结论 MRSA和MRCNS仍然是目前革兰阳性菌中主要的问题;未发现VISA和VRSA。出现少数铜绿假单胞菌(0.5%)、鲍曼不动杆菌(1.6%)和肺炎克雷伯菌(0.25%)泛耐药株。临床应对这些泛耐药株进行流行病学调查并采取相应的控制措施。     

异质性耐万古霉素金黄色葡萄球菌的研究进展

医院内耐甲氧西林金黄色葡萄球菌(金葡菌)(methicillin—resistant S．aureus，MRSA)不但感染率高，治疗困难，且病死率也高。万古霉素能有效的治疗革兰阳性球菌感染，仍是目前的首选药物，近年来，许多实验室报告MRSA对万古霉素为敏感，但临床疗效并不十分理想，甚至治疗失败。许多研究认为可能与葡萄球菌对万古霉素异质性即不均一性的耐药有关。国外对异质性耐万古霉素金葡菌(hetero—VRSA)、     

金黄色葡萄球菌对临床常用抗菌药物的敏感性及毒力基因检测分析

目的分析金黄色葡萄球菌(简称金葡菌)对临床常用抗菌药物的敏感性及毒力基因检测结果。方法分离金葡菌129株行药敏试验,金葡菌分离自胸腹水、脑脊液及血液等无菌体液标本中,万古霉素等常用抗菌药物对金葡菌的最低抑菌浓度(MIC)采用琼脂稀释法检测,耐甲氧西林金葡菌(MRSA)内耐药基因mec C、mec A和毒力基因sas X与杀白细胞毒素(PVL)基因采用聚合酶链反应(PCR)检测。结果苯唑西林琼脂稀释结果显示,70株为MRSA,其余59株为甲氧西林敏感金葡菌(MSSA);对临床分离所得的45株MRSA分别采用mec A、mec C基因的PCR引物进行PCR扩增,mec A阳性检出率为100.00%,sas X基因阳性检出率为46.67%(21/45),sas X基因阴性检出率为53.33%(24/45),mec C、PVL均未检出; MRSA对β内酰胺类药物的耐药率高于MSSA,且对左氧氟沙星、阿米卡星、庆大霉素等非β内酰胺类药物也有耐药性,但75.00%以上MRSA对甲氧苄啶与利福平比较敏感。MSSA对β内酰胺类药物和非β内酰胺类药物均比较敏感,耐药率均低于11.00%;sas X阴性或sas X阳性的MRSA对左氧氟沙星、磷霉素和β内酰胺类抗生素均比较耐药,但sas X阴性基因与sas X阳性基因对甲氧苄啶、利福平、阿米卡星及庆大霉素的耐药率不完全一致。结论 MRSA对临床大多数抗菌药物均有耐药性,临床需对MRSA加强监测。     

84株住院患者金黄色葡萄球菌的分布及耐药性分析

目的分析住院患者中分离的金黄色葡萄球菌耐药情况,为临床合理使用抗菌药物提供依据。方法用API系统鉴定细菌,纸片扩散（K—B）法检测84株金黄色葡萄球菌对12种抗菌药物的敏感性。结果84株金葡菌中,MRSA69株（82．1％）。除了万古霉素外,MRSA和MSSA对抗菌药物的耐药率不同：MSSA除了对青霉素（80％）和四环素（55％）外,对其他抗菌药物的耐药率小于30％;MRSA对利福平（4％）、复方磺胺异唑和米诺环素的耐药率分别为4％、37％和52％,对其他抗菌药物的耐药率均大于90％,MRSA和MSSA相比,除万古霉素和利福平外,MRSA对其他抗菌药物的耐药率远大于MSSA。结论临床分离的金葡菌中,MRSA对多种抗菌药物耐药率较高,许多MRSA菌株为多重耐药菌,临床实验室应加强对MRSA的耐药监测。     

异质性万古霉素中介金黄色葡萄球菌：困扰我们的难题

万古霉素是治疗甲氧西林耐药金葡菌（MRsA）感染的有效药物,也是治疗该菌感染的最后选择,目前该药已在临床上广泛使用。虽然万古霉素耐药金葡菌（VRsA）在全球的检出率很低,但万古霉素低水平耐药的金葡菌,包括异质性万古霉素中介金葡菌（hVIsA）和万古霉素中介金葡菌（VISA）却在多个国家和地区广泛流行。     

Emergence in Asian countries of Staphylococcus aureus with reduced susceptibility to vancomycin

To investigate the prevalence of Staphylococcus aureus with reduced susceptibility to vancomycin among methicillin-resistant S. aureus (MRSA) strains in Asian countries, a total of 1,357 clinical isolates of MRSA collected from 12 Asian countries were screened by using brain heart infusion agar plates containing 4 mg of vancomycin per liter. The presence of strains that were heterointermediately resistant to vancomycin (hVISA) was confirmed by population analysis. Of 347 (25.6%) MRSA isolates that grew on the screening agar plates, 58 isolates (4.3%) were hVISA. hVISA strains were found in India, South Korea, Japan, the Philippines, Singapore, Thailand, and Vietnam. However, neither vancomycin-intermediate S. aureus nor vancomycin-resistant S. aureus isolates were found among MRSA isolates from Asian countries in this survey.     

Methicillin-resistant Staphylococcus aureus (MRSA) isolated in hospitals in Fukuoka City area]

Bacteriological and clinical studies were carried out on 280 strains of Staphylococcus aureus isolated in hospitals in Fukuoka city area from September 1990 to March 1991. Of all S. aureus strains studied 116 (41.4%) were methicillin-resistant. The proportion of MRSA in S. aureus isolates from outpatients was 10% (11/109), 69.2% (90/130) in those from inpatients. The average age of patients with isolated MRSA was 70.5 +/- 16.9 years and that of patients with isolated MSSA, 44.2 +/- 29.3. MRSA strains were recovered mainly from sputum and pus. The isolation rate did not vary significantly with hospitals of different size (number of beds). Of all MRSA strains 48 (41.3%) produced coagulase type VII. As for drug susceptibility, MRSA strains with coagulase type VII were more sensitive to clindamycin and more resistant to minocyclin compared to MRSA with other coagulase types.     

Activity of clindamycin against Staphylococcus aureus and Staphylococcus epidermidis from four UK centres.

MICs of penicillin, methicillin, clindamycin, erythromycin, sodium fusidate and gentamicin were determined by an agar dilution method for 300 current isolates of Staphylococcus aureus and 100 of S. epidermidis, collected from four centres, and 38 stock strains of methicillin-resistant S. aureus (MRSA). All but one of the 300 current isolates of S. aureus were sensitive to clindamycin (MIC less than 0.5 mg/l), with an MIC90 of 0.12 mg/l. Of a total of 39 MRSA strains, 11 (28.2%) were resistant to clindamycin (MIC greater than 32 mg/l); all of these strains were also resistant to erythromycin. Ten of the 100 strains of S. epidermidis were resistant to clindamycin; they came from a reasonably equal geographical distribution and were also resistant to erythromycin. The results suggest that clindamycin might still be useful as a second-line agent for infections caused by S. aureus and S. epidermidis, although its activity against MRSA was limited to approximately two-thirds of the MRSA strains tested in this study.     

National survey of molecular epidemiology of Staphylococcus aureus colonization in Belgian cystic fibrosis patients

OBJECTIVES: Epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) is poorly defined in cystic fibrosis (CF) patients, and S. aureus detection may be hampered by the presence of small colony variants (SCVs). We conducted a multicentre survey to determine the prevalence of S. aureus and MRSA colonization in Belgian CF patients and characterize the phenotype and clonal distribution of their staphylococcal strains. METHODS: S. aureus isolated from CF patients attending nine CF centres were collected. Oxacillin resistance was detected by oxacillin agar screen and mecA PCR. Antibiotic susceptibility was tested by microdilution. MRSA strains were genotyped by PFGE and SCCmec typing and compared with hospital-associated MRSA strains. RESULTS: Laboratories used a diversity of sputum culture procedures, many of which appeared substandard. S. aureus was isolated from 275/627 (44%) CF patients (20% to 72% by centre). The prevalence of SCV colonization was 4%, but SCVs were almost exclusively recovered from patients in two centres performing an SCV search. Phenotypically, 14% of S. aureus isolates were oxacillin-resistant: 79% carried mecA and 19% were SCVs lacking mecA. The mean prevalence of 'true' MRSA colonization was 5% (0% to 17% by centre). By PFGE typing, 67% of CF-associated MRSA were related to five epidemic clones widespread in Belgian hospitals. CONCLUSIONS: This first survey of S. aureus colonization in the Belgian CF population indicated a diversity in local prevalence rates and in proportion of oxacillin-resistant and SCV phenotypes, probably related to variation in bacteriological methods. These findings underscore the need for standard S. aureus detection methods and MRSA control policies in Belgian CF centres.     

我院2007-2008年金黄色葡萄球菌耐药性分析

目的了解我院2007—2008年临床分离金葡菌对各类抗菌药物的耐药性。方法按统一方案、采用统一的材料、方法和判断标准(CLSI2006年)对我院从2007年1月—2008年12月分离的金葡菌行耐药性监测。结果我院2007—2008年住院患者金葡菌临床分离株共281株,127株为MRSA,占45.2%;2年的MRSA分离率差异无统计学意义;随着年龄的增加MRSA感染者增多;MRSA对青霉素、头孢唑林、克林霉素、庆大霉素、妥布霉素、红霉素、四环素、磷霉素、环丙沙星、左氧氟沙星、莫西沙星和利福平的耐药率均高于MSSA,差异有统计学意义;对磺胺甲口恶唑-甲氧苄啶的敏感率两者差异无统计学意义;MRSA对万古霉素、替考拉宁、利奈唑胺和奎奴普丁-达福普汀的敏感率仍保持为100%;未发现万古霉素中介株(VISA)和耐药株(VRSA)。2008年分离的金葡菌对莫西沙星的耐药率显著升高。结论MRSA对多种抗菌药物耐药率高,应规范临床用药,加强MRSA耐药性监测,隔离MRSA感染者,防止医源性传播。     

Distribution of capsular and surface polysaccharide serotypes of Staphylococcus aureus

Because of its ability to cause serious and fatal infections, Staphylococcus aureus remains one of the most feared microorganisms. Methicillin-resistant S. aureus (MRSA) has long been a common pathogen in healthcare facilities, but within the past decade, it has emerged as a problematic pathogen in the community setting as well. The severe consequences of infection heighten the importance of prevention. To analyze the potential applicability of a putative S. aureus polysaccharide conjugate vaccine, we tested 714 German methicillin-susceptible S. aureus (MSSA) and MRSA strains for their capsular and surface polysaccharide serotype by slide agglutination with specific antibodies (anti-T5-DT, anti-T8-DT, anti-336-rEPA). The strain serotypes were confirmed by immunodiffusion using lysostaphin-digested cell lysates. Regarding MRSA strains representing 86 unique spa types and thus covering >90% of MRSA spa types registered, 39 (45.3%) were type 5, 36 (41.9%) were type 8, and 11 (12.8%) were type 336. Of particular interest, type 336 was the second most common serotype among MRSA isolates collected from 10 different laboratories (40 isolates per site) covering university hospitals, general hospitals, and clinics throughout Germany. Type 8-positive strains were more prevalent among isolates recovered from anterior nares of patients who did not subsequently develop S. aureus bacteremia compared with those who became bacteremic with this pathogen. In conclusion, the addition of the newly described type 336 to a capsular polysaccharide-protein conjugate vaccine could extend the coverage substantially and would include virtually all MSSA and MRSA strains currently circulating in Germany.     

金黄色葡萄球菌毒力基因检测及Spa分型研究

目的 研究深圳市南山区2009-2015年医院内患者临床检测标本、医院台面与医护人员双手涂抹样以及食物中毒样本中金黄色葡萄球菌（Staphylococcus aureus,SA）蛋白A基因多态性分型（single locus DNA-sequencing of the repeat region of the Staphylococcus protein A gene,Spa）的特征及毒力基因分布情况。方法 采用多重PCR方法检测SA的mecA与femA基因,PCR方法检测24个毒力基因以及SA蛋白A基因,PCR产物测序后序列上传数据库进行比对。结果 87株SA共检出48株耐甲氧西林金黄色葡萄球菌（methicillin-resistant S. aureus,MRSA）,检出率为55.2%。共检出21种毒力基因,检出率60%的毒力基因有LUKDE（65.5%）、SHE（67.8%）、mpHLG 2（85.1%）、HLD（93.1%）和 HLA（100.0%）。94.3%菌株携带5个以上毒力基因。三类样本中有11种毒力基因检出率差异有统计学意义,分别是SEB、mpSEC、mpSEJ、mpSEO、TST、HLB、HLD、mpHLG 1、mpHLG 2,mpETB和PVL。其中mpETB与PVL仅在患者中检出,肠毒素基因在食物中毒株中携带率较高。MRSA与甲氧西林敏感金黄色葡萄球菌（methicillin-sensitive S.aureus,MSSA）的3种毒力基因检出率差异有统计学意义,分别是mpETA、PVL及mpHLG 2;MRSA的毒力基因mpETA与PVL检出率明显高于MSSA（P=0.033, P=0.030）,而mpHLG 2检出率明显低于MSSA（P=0.021）。87株SA分为24种Spa型,患者优势型别为t030（30.0%）与t437（36.7%）,医院其他样本优势型别为t091（50.0%）,食物中毒优势型别为t127（36.8%）与t091（21.1%）。结论 三类样本部分毒力基因检出差异有统计学意义。MRSA与MSSA携带毒力基因差异无统计学意义。三类样本中均存在优势的Spa型别。     

Identification of methicillin-resistant Staphylococcus aureus (MRSA): Comparison of a new molecular genetic test kit (GenoType MRSA) with standard diagnostic methods

Results obtained from 188 isolates of staphylococci using standard diagnostic methods for identifying MRSA were compared with those achieved with a newly available molecular genetic test kit, the GenoType, Version 1, MRSA (Hain Lifescience GmbH, Nehren, Germany). The GenoType MRSA detects the mecA gene and, in addition, a highly specific sequence for Staphylococcus aureus (S. aureus) by polymerase chain reaction (PCR) and reverse hybridization. There was a 100% overall correlation between the results of conventional and molecular genetic testing. 143 isolates were tested positive for MRSA, 10 isolates were identified as oxacillin-sensitive Staphylococcus aureus strains (MSSA), and 35 isolates were coagulase-negative staphylococci of various species. However, five of the 143 MRSA strains yielded ambiguous results with the first line standard tests and therefore required additional testing leading to delay of definitive diagnosis. As expected, mecA could not only be detected in MRSA strains, but also in coagulase-negative staphylococci. The reliable identification as S. aureus from the same isolate is therefore an essential prerequisite for MRSA diagnosis. The GenoType MRSA fulfills this requirement by parallel detection of a S. aureus-specific sequence and the mecA gene. Molecular genetic testing with the GenoType MRSA kit needs much less time than conventional microbiological methods. Therefore genetic testing provides not only a considerable advantage with respect to reliability but also to speed.     

Staphylococcus aureus: the new adventures of a legendary pathogen

Nosocomial infections with strains of methicillin-resistant Staphylococcus aureus (MRSA) began to emerge in the 1960s, are increasing in frequency, and tend to have worse outcomes than infections due to methicillin-susceptible S aureus. Community-associated MRSA infections emerged in the 1990s. Community-associated MRSA strains have up to now been epidemiologically and bacteriologically distinct from hospital-associated MRSA strains, but in a new twist, MRSA strains that have sofar been only community-associated are invading the hospital. Another worrisome trend is increasing resistance to vancomycin (Vancocin).     

Carrier state and comparative study of methicillin-resistant Staphylococcus aureus from the staff and patients]

The nasal carriage of Staphylococcus aureus in 529 staff was screened. S. aureus from staff and patients whose minimum inhibitory concentration (MIC) of methicillin was larger than 12.5 micrograms/ml by agar dilution was defined as Methicillin-resistant S. aureus (MRSA). Coagulase typing was performed by DENKA SEIKEN kit. Hands of ward staff were screened before and after contact with the MRSA carriers and after hand washing. The nasal acquisition rate of S. aureus and MRSA for staff was 27.6% and 8.5%. The rate of ward staff for nasal carriers of MRSA was 91.1%. Coagulase type II strains from ward staff and inpatients were dominant. In some cases MRSA was detectable after hand washing: In MRSA infection ward staff played a dangerous role as a vector.