后天获得性耐甲氧苯青霉素金黄色葡萄球菌菌落感染在妊娠患者中的临床现状

目的：本研究旨在回顾后天获得性耐甲氧苯青霉素金黄色葡萄球菌菌落（MRSA）感染在孕妇中的现状与治疗。方法：用图表方式回顾分析2000年1月1日至2004年7月30日间诊断为MRSA感染的孕妇。收集的资料包括人口统计学特征、临床表现、细菌培养及药敏结果。比较患者及同期正常孕妇人群的妊娠结局。结果：共有57份有效图表。其中2000年2例，2001年4例，2002年11例，2003年23例，2004年1～7月份17例。同时并存的疾病包括人免疫缺陷病毒和获得性免疫缺陷综合征（13％）、哮喘（1l％）、糖尿病（9％）。妊娠中期细菌培养阳性率最高（46％）。96％的患者为皮肤和软组织感染，18％的患者于产后感染。最常见的病变部位足四肢末端（44％），其次是臀部（25％）和乳房（乳腺炎）（23％）。58％的患者反复感染，63％的患者需要住院治疗。分离出的所有MRSA都对甲氧苄氨嘧啶一磺胺甲基异恶唑、万古霉素及利福平敏感。其它的敏感抗生素包括庆大霉素（98％）和左氧氟沙星（84％）。     

五味消毒饮联合红霉素对MRSA生物膜作用的初步研究

目的探讨五味消毒饮联合红霉素对耐甲氧西林金黄色葡萄球菌(MRSA)的体外抑菌效果。结论用微量稀释法分别测定红霉素、五味消毒饮的最低抑菌浓度(MIC)及MRSA生物膜MIC(SMIC),再用微量棋盘稀释法进行联合抑菌试验,观察五味消毒饮联合红霉素抗MRSA的作用。结果五味消毒饮、红霉素单独及联合检测时MRSA的最低抑菌浓度(MIC)和MRSA生物膜MIC(SMIC)分别为>1000g/ml、8μg/ml、2μg/ml+/1000g/ml和>1000g/ml、32μg/ml、8μg/ml+1000g/ml。结论五味消毒饮联合红霉素可增强对MRSA的抑菌作用,为临床MRSA的感染提供了新的治疗思路。     

住院患儿耐甲氧西林金黄色葡萄球菌的PFGE分型及耐药性

目的了解某院住院患儿感染耐甲氧西林金黄色葡萄球菌(methicillin-resistant Staphylococcus aureus,MRSA)的分子型别及其对临床常用抗生素的耐药情况,为防控MRSA感染提供依据。方法收集2018年4～6月某院患儿各类标本中分离出的MRSA 53株,采用VITEK-2Compact全自动微生物系统鉴定,头孢西丁纸片法进行MRSA菌株复核,最低抑菌浓度法(minimum inhibitory concentration,MIC)进行药敏试验,运用脉冲场凝胶电泳(pulse field gel electrophoresis,PFGE)对MRSA进行分子分型。结果 53株MRSA以呼吸科、血液科为主;对青霉素、苯唑西林耐药,对利福平、庆大霉素、环丙沙星、复方新诺明、左氧氟沙星、莫西沙星的耐药率较低(<10%),尚未发现耐呋喃妥因、奎奴普汀、万古霉素和利萘唑胺的菌株;多重耐药的MRSA对所有β内酰胺类高度耐药;经PFGE分型,共得到38种PFGE带型,其中优势型别R1型菌株共占16. 7%。结论 MRSA耐药较为严重,应加强重点科室的感染管理,防止多重耐药菌传播;重点关注出现交叉感染的高发科室和重点人群的感染防控工作。     

Survey of methicillin-resistant Staphylococcus aureus (MRSA) carriage in healthy college students, Hawai'i

Currently, the carriage rate for Community-Acquired Methicillin Resistant Staphylococcus aureus (CA-MRSA) is unknown in Hawai'i. This survey focuses on a healthy population of 95 college students and 5 faculty who completed a survey related to possible risk factors for colonization of Staphylococcus aureus and were sampled for S. aureus from their anterior nares. Thirty-three (33%) subjects were carrying Staphylococcus aureus and of those, 3 (3%) carried MRSA. There was no significant association between Staphylococcus aureus carriage and ethnicity, gender exposure to seawater, prior Staphylococcus aureus infections, recent antibiotic use, or pets. Additional testing of a larger group of healthy individuals would be beneficial in assessing factors associated with CA-MRSA and Methicillin-susceptible Staphylococcus aureus (MSSA) carriage in Hawai'i.     

肺部肿瘤化疗对癌症患者耐甲氧西林金黄色葡萄球菌(MRSA)的影响

目的:研究癌症患者肺部肿瘤化疗后耐甲氧西林金黄色葡萄球菌(MRSA)变化情况。方法:回顾性分析100例肺部肿瘤化疗患者的MRSA感染资料。从感染者鼻、喉和其他感染部位获得MRSA定植拭子,进行生物检验。结果:44例患者为MRSA携带者。MRSA败血症48例,其中42%的患者中性粒细胞计数<500/μl。MRSA致命并发症仅8例。MRSA败血病死率为14.6%。结论:化疗抗肿瘤可用于MRSA感染的肺癌患者,并且不必减少剂量或延迟治疗。     

耐甲氧西林金黄色葡萄球菌PBP2a相互作用蛋白的筛选

目的通过建立细菌双杂交技术,筛选MRSA中与PBP2a相互作用的蛋白。方法利用PCR扩增,获得PBP2a蛋白转肽酶活性区(TPase)的编码基因,插入pRBR构建成诱饵质粒pBR-PBP2a。提取MRSA N315株基因组DNA,经Sau3AⅠ部分酶切后连接到pRAC质粒的BamHⅠ位点,获得基因组DNA表达文库;将文库质粒转化入含诱饵质粒pBR-PBP2a的报告菌株KS1,利用细菌双杂交技术进行筛选,获得与诱饵质粒编码的融合蛋白相互作用的猎物,对猎物中编码序列进行DNA测序和生物信息学分析,确定与PBP2a发生相互作用的蛋白质或多肽。结果成功构建了pBR-PBP2a诱饵质粒,可表达PBP2a TPase与大肠埃希菌RNA聚合酶α亚单位N端序列的融合蛋白。所构建的MRSA N315株基因组文库覆盖率达9倍,满足文库筛选的需要。将文库转化含诱饵质粒和报告基因的KS1宿主菌,利用细菌双杂交技术经3次筛选,共获得9个猎物克隆,其报告基因的活性均升高2倍以上,对9个猎物质粒进行了测序,信息学分析表明它们均来自于MRSA N315株基因组,插入片段最长者648 bp,最短者334 bp,9个插入片段中含14个编码基因,...     

Carriage of methicillin-resistant Staphylococcus aureus in a Queensland Indigenous community

OBJECTIVE: To determine the prevalence of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) carriage and infection among children living in an Indigenous community in Queensland. DESIGN, SETTING AND PARTICIPANTS: Swabs for culture of S. aureus were collected from the nose, throat and skin wounds of primary school children. MAIN OUTCOME MEASURES: MRSA carriage, antibiotic sensitivity, genotype, and presence of the virulence factor Panton-Valentine leukocidin (PVL); and epidemiological risk factors for MRSA carriage. RESULTS: 92 (59%) of 157 eligible children were included in the study. Twenty-seven (29%) carried S. aureus; 14 of these (15% of total) carried MRSA. MRSA was isolated from 29% of wound swabs, 8% of nose swabs, and 1% of throat swabs. Fourteen of 15 MRSA isolates were sensitive to all non-beta-lactam antibiotics tested. Eight children (9%) carried CA-MRSA clonal types: six carried the Queensland clone (ST93), and two carried the South West Pacific clone (ST30). All these isolates carried the virulence factor PVL. The remaining six children carried a hospital-associated MRSA strain (ST5), negative for PVL. CONCLUSIONS: We have identified a high prevalence of CA-MRSA carriage in school children from a Queensland Indigenous community. In this setting, antibiotics with activity against CA-MRSA should be considered for empiric therapy of suspected staphylococcal infection. Larger community-based studies are needed to improve our understanding of the epidemiology of CA-MRSA, and to assist in the development of therapeutic guidelines for this important infection.     

合肥地区耐甲氧西林金黄色葡萄球菌SCCmec分型及耐药性分析

目的 研究合肥市临床分离甲氧西林耐药金黄色葡萄球菌的SCCmec分型及药物敏感性,以了解本地区MRSA流行株的耐药表型和基因型特征。方法 从5家教学医院随机选取2016年1月-2021年12月264株非重复MRSA菌株,头孢西丁纸片扩散法筛查MRSA,PCR扩增mecA基因,多重PCR进行MRSA的SCCmec分型。WHONET5.6软件分析不同SCCmec型别MRSA菌株对抗菌药物的敏感性。结果 264株MRSA SCCmecⅡ型156株(59.1%),SCCmecⅣa型92株(34.8%),SCCmecⅢ型4株(1.5%),12株未分型(4.5%)。156株SCCmecⅡ型和92株SCCmecⅣa型MRSA对万古霉素、利奈唑胺、达托霉素和替加环素的敏感率为100%。Ⅱ型对环丙沙星、左氧氟沙星、莫西沙星和庆大霉素对的耐药性高于Ⅳa型,差异具有统计学意义。Ⅱ型和Ⅳa红霉素、克林霉素、四环素、复方磺胺甲噁唑和利福平在分型的耐药性差异无统计学意义。     

Control of methicillin-resistant Staphylococcus aureus (MRSA) in an Australian metropolitan teaching hospital complex

In April 1982, a patient infected with methicillin-resistant Staphylococcus aureus (MRSA) was transferred to the Royal Perth Hospital from the Royal Darwin Hospital. Within three months, 19 patients and four staff members had become infected or colonized with MRSA. The outbreak was terminated only after all colonized inpatients were transferred to a separate isolation unit. After the outbreak, all new patients and new employees who had been in hospitals outside Western Australia in the previous 12 months were screened. From June 1, 1982, to June 30, 1984, 28 of the 649 patients (4.3%) screened on admission to the Royal Perth Hospital were found to be harbouring MRSA. During the same period only one of the 468 persons (0.2%) screened on application for employment at the Hospital was found to be colonized with MRSA. Since the policy of screening new patients and staff from hospitals outside Western Australia was introduced, no serious outbreak of MRSA has occurred.     

Bacteriophage types of methicillin-resistant Staphylococcus aureus in a tertiary care hospital

Background

Phage typing had been utilised extensively to characterise methicillin-resistant Staphylococcus aureus (MRSA) outbreak strains in the past. It is an invaluable tool even today to monitor emergence and dissemination of MRSA strains.

Aims

The aim of this study was to determine the prevalent phage types of MRSA in south India and the association between phage types, antibiotic resistance pattern and risk factors.

Method

A total of 48 non-duplicate MRSA strains recovered from various clinical samples during January to December, 2010 were tested against a panel of anti-staphylococcal antibiotics. Phage typing was carried out at the National Staphylococcal Phage Typing Centre, New Delhi. Out of 48, 32 hospitalised patients were followed up for risk factors and response to empirical and post sensitivity antibiotic therapy. The risk factors were compared with a control group of 30 patients with methicillin sensitive Staphylococcus aureus (MSSA) infection.

Results

Amongst the five prevalent phage types, 42E was most common (52%), followed by a non-typable variant (22.9%), 42E/47/54/75 (16.6%), 42E/47 (6.2%) and 47 (2%). Phage type 42E was the predominant strain in all wards and OPDs except in the ICU where 42E/47/54/75 was most common. Although not statistically significant, strain 42E/47/54/75 (n=8) showed higher resistance to all drugs, except ciprofloxacin and amikacin, and were mostly D-test positive (87.5%) compared to the 42E strain (32%). Duration of hospital stay, intravenous catheterisation and breach in skin were the most significant risk factors for MRSA infection.

Conclusion

We found MRSA strain diversity in hospital wards with differences in their antibiotic susceptibility pattern. The findings may impact infection control and antibiotic policy significantly.     

Treatment failure due to methicillin-resistant Staphylococcus aureus (MRSA) with reduced susceptibility to vancomycin.

We report the first instance in Australia of treatment failure due to a strain of methicillin-resistant Staphylococcus aureus (MRSA) with reduced susceptibility to vancomycin--heteroresistant vancomycin-intermediate S. aureus (hVISA). The infection occurred in a 41-year-old man with multiple risk factors. No transmission of the organism to other patients or the environment was detected. This case may herald the beginning of a new phase of staphylococcal resistance in Australia.     

DNA fingerprinting of methicillin-resistant Staphylococcus aureus (MRSA) by pulsed-field gel electrophoresis (PFGE) in a teaching hospital in Malaysia

Methicillin-resistant Staphylococcus aureus (MRSA) has been prevalent in our hospital over the last three years. Differentiation among MRSA strains by DNA typing in addition to antibiotic resistance pattern surveillance is crucial in order to implement infection control measures. The aim of this study was to characterize MRSA isolates from patients admitted to Hospital Universiti Kebangsaan Malaysia (HUKM) by phenotypic (analyses of antibiotic susceptibility pattern) and genotypic (PFGE) techniques to determine the genetic relatedness of the MRSA involved and to identify endemic clonal profiles of MRSA circulating in HUKM. Seventy one MRSA strains collected between January to March 2000 from patients from various wards in HUKM were tested for antimicrobial resistance and typed by pulsed-field gel electrophoresis (PFGE). Four major types of PFGE patterns were identified (A, B, C and D) among MRSA strains. Two predominant PFGE types were recognised, Type A (59.2%) and Type B (33.8%). Most of these strains were isolated from ICU, Surgical wards and Medical wards. MRSA strains with different PFGE patterns appeared to be widespread among wards. Strains with the same antibiotype could be of different PFGE types. Most of isolates were resistant to ciprofloxacin, erythromycin, gentamicin and penicillin. One isolate with a unique PFGE pattern Type D and susceptible to gentamicin was identified as a different clone. Some isolates obtained from the same patient showed different PFGE subtypes suggesting that these patients were infected/colonized with multiple MRSA strains. PFGE analysis suggests that MRSA strains with different PFGE types was propagated within our hospital. The relationship between antibiotic susceptibility and PFGE patterns was independent. The ability of PFGE technique in differentiating our MRSA strains make it a method of choice for investigating the source, transmission and spread of nosocomial MRSA infection, and thus an appropriate control programme can be implemented to prevent the spread of MRSA infection.