医务人员鼻前庭机会致病菌携带的调查

目的了解重症监护病房（ICU）医务人员鼻前庭带菌情况,以加强ICU医务人员医院感染的预防与控制。方法采用常规方法对ICU工作的93名医务人员和对照组的98名医务人员的鼻前庭拭子进行培养和菌种鉴定。结果从191名医务人员的鼻拭子中分离到214株机会致病菌,其中金黄色葡萄球菌8株,携带率4.19%,均为甲氧西林敏感金黄色葡萄球菌（MSSA）,凝固酶阴性葡萄球菌131株,携带率93.71%,主要是表皮葡萄球菌和溶血葡萄球菌,其中耐甲氧西林凝固酶阴性葡萄球菌（MRCNS）占50.3%,革兰阴性杆菌27株,携带率14.14%,主要是肺炎克雷伯菌和阴沟肠杆菌,未发现产超广谱β-内酰胺酶（ESBLs）细菌;ICU医务人员鼻前庭金黄色葡萄球菌携带率（6.5%）、MRCNS的携带率（60.2%）、革兰阴性杆菌的携带率（26.9%）均明显高于普通科室（P〈0.05）。结论医院内医务人员间鼻前庭机会致病菌携带率较高,不同科室医务人员之间的机会致病菌的携带存在明显差异,应加强医院医务人员自身感染的预防与控制,特别是长期在ICU工作的医务人员。     

肾移植病房耐甲氧西林金黄色葡萄球菌随机扩增多态DNA分型研究

目的 研究医院肾移植病房耐甲氧西林金黄色葡萄球菌(MRSA)的分子流行病学特征,以确定病房内是否存在MRSA流行.方法 用头孢西丁纸片扩散法检测MRSA,用双重PCR方法检测金黄色葡萄球菌的femA,mecA基因,采用随机扩增多态DNA技术(RAPD),对肾移植病房一段时间内临床患者感染部位及环境和医务人员分离的MRSA作同源性分析.结果 16例患者中有5例感染MRSA;从57份医护人员鼻腔、手部、环境分离出1株MRSA;5株患者MRSA的RAPD分型具有较高的同源性;医护人员分离的MRSA与患者分型结果无同源性.结论我们医院肾移植病房存在严重的MRSA局部流行,应及时检测MRSA,防止医院感染菌株的播散.     

肿瘤化疗住院患者金黄色葡萄球菌的携带及耐甲氧西林金黄色葡萄球菌的筛选

目的调查肿瘤化疗患者鼻前庭及手上金黄色葡萄球菌的携带及耐甲氧西林金黄色葡萄球菌（MRSA）的分布。方法常规法分离鉴定165名化疗患者鼻前庭及手上的金黄色葡萄球菌，头孢西丁药敏纸片法筛选MRSA。结果患者金黄色葡萄球菌及MRSA总携带率分别为45．45％、13．33％。结论肿瘤化疗住院患者易携带金黄色葡萄球菌及MRSA，应重视其检测。     

医院感染耐甲氧西林金黄色葡萄球菌耐药性与SCCmec分型及同源性研究

目的 研究医院耐甲氧西林金黄色葡萄球菌(MRSA)的耐药性及分子流行病学特点,为预防和控制医院感染提供参考.方法 采用药敏纸片法(K-B法)、SCCmec分型及葡萄球菌A蛋白(spa)分型技术,2009年3-4月对烧伤科、ICU、呼吸内科、急诊科、血液内科、儿童急救科和儿童呼吸科住院患者、医务人员及环境分离的MRSA,进行了药敏试验和同源性分析,并检测其杀白细胞毒素(pvl)基因.结果 从1352份标本中分离出108株金黄色葡萄球菌,MRSA为54株占50.0％,主要分离于烧伤科42株占77.8％;分离的临床菌株总体耐药率较高,除万古霉索外耐药率均＞50.0％,未发现万古霉素耐药株;SCCmec分型结果显示,54株MRSA以Ⅲ型为主占68.5％,pvl基因均为阴性;进行spa分型研究的23株MRSA中,22株为t030,1株为t2270,呈现高度的克隆一致性.结论 医护人员MRSA带菌率较高,部分医务人员、住院患者和环境中分离的MRSA有较高的同源性,存在人与人和人与环境之间的MRSA传播.     

开放性伤口分离阴沟肠杆菌的耐药性及多态性DNA分型研究

目的了解地震后群体受伤患者开放性伤口分离阴沟肠杆菌的耐药性,并对其同源性进行研究,为群体外伤紧急医疗救治过程中是否存在医院感染提供科学依据。方法对汶川地震后14例开放性骨折或骨筋膜室综合症受伤患者的创面分离阴沟肠杆菌进行耐药性分型;同时留取菌株,采用随机扩增多态性DNA(RAPD)指纹图基因分型方法进行同源性分析。结果 6株阴沟肠杆菌的耐药性分型分为3型,RAPD分型分为4型,耐药谱分型相同的菌株RAPD分型不一定相同;同一患者上、下肢分泌物中分离的菌株同源性为100.0%;有5株菌株的同源性>90.0%,菌株间的差异非常小,可能存在耐药菌株的相互传播。结论群体受伤患者伤口感染细菌耐药性强,且伤口感染的同源性较高,存在医院感染的可能;因此,在突发灾难救援工作中,应重视医院感染控制工作,避免耐药细菌的传播和流行。     

山区基层医院葡萄球菌感染的耐药性调查

目的了解山区基层医院葡萄球菌医院感染和耐药现状,以采取有效措施控制医院感染. 方法采集2000年1月～2003年12月,我院医院感染患者临床各类标本中分离的葡萄球菌137株,进行了细菌鉴定、耐甲氧西林葡萄球菌(MRS)检测和KB法药敏试验,并进行统计与分析. 结果 137株葡萄球菌分为7种,以金黄色葡萄球菌(SAU)分离率最高,为35.8%;137株中耐甲氧西林金黄色葡萄球菌(MRSA)占SAU总数的34.7%;耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)占凝固酶阴性葡萄球菌(CNS)总数的31.8%;药敏结果显示甲氧西林敏感葡萄球菌(MSS)耐药率明显低于MRS株. 结论山区基层医院同样存在MRS感染,且比较严重,应采取切实措施,以有效监测与控制MRS的发生与流行.     

耐甲氧西林金黄色葡萄球菌感染的流行病学研究

目的了解某院患者耐甲氧西林金黄色葡萄球菌（MRSA）的感染和医院环境中MRSA的污染情况,研究临床和相应环境标本中MRSA的同源性,寻找MRSA医院感染的传染源及传播途径。方法采用Vitek-2细菌鉴定系统鉴定金黄色葡萄球菌;以头孢西丁纸片琼脂扩散法和mecA基因聚合酶链反应（PCR）鉴定MRSA随机扩增多态性DNA（RAPD）技术进行同源性分析。结果临床标本分离的金黄色葡萄球菌中,MRSA占58．54％（24／41）;环境标本分离的金黄色葡萄球菌中,MRSA占38．10％（16／42）。MRSA菌株经RAPD扩增后均可见数量不等（4～6条）的条带,分型率达100％。经聚类分析,24株临床MRSA菌株分为4型,其中以RAPDⅠ型为主（14株）;16株环境MRSA菌株分为3型,亦以RAPDⅠ型为主（13株）。烧伤科与神经外科各有4例患者及其周围环境分离出同源菌。结论该院临床标本及医院环境标本中MRSA分离率较高,RAPDⅠ型MRSA为其主要流行株且存在RAPDⅠ型MRSA菌株克隆传播。外源性途径是MRSA医院感染的主要来源。     

196株金黄色葡萄球菌的分布及耐药性分析

目的 分析近3年医院住院患者金黄色葡萄球菌(SAU)分离株的临床分布及耐药性,为指导临床治疗SAU感染合理使用抗菌药物提供帮助.方法 对196株SAU的分布及耐药性进行调查分析,严格按照《全国临床检验操作规程》进行SAU培养与鉴定,采用CLSI推荐的KB法进行药敏试验.结果 196株SAU中,48.5％为耐甲氧西林金黄色葡萄球菌(MRSA),51.5％为甲氧西林敏感金黄色葡萄球菌(MSSA);在95株MRSA中,ICU、呼吸科、神经内科检出率较高,儿科检出率相对较低;SAU对多种常用抗菌药物均产生了不同程度的耐药;MRSA的耐药率均高于MSSA.结论 SAU引起的耐药现象严重,加强耐药性监测,合理使用抗菌药物非常重要.     

重症监护病房医务人员鼻前庭细菌定植情况及耐药性调查

目的了解重症监护病房（ICU）医务人员鼻前庭病原菌定植情况,为加强ICU医院感染的预防与控制提供依据。方法2015年5月主动筛查某院ICU非感染状态下的医务人员鼻前庭细菌定植情况,并进行细菌培养、菌株分离及菌种鉴定。分析调查结果并与同期患者检出细菌的耐药情况进行比较。结果共调查医务人员96名,从鼻前庭标本中分离病原菌43株,分别来自不同的医务人员,病原菌分离率及携带率均为44.79%。分离的主要病原菌为金黄色葡萄球菌（15株,占34.88%）,其次为产气肠杆菌（9株,占20.93%）、肺炎克雷伯菌（7株,占16.28%）等。医生、经常吸烟及从不锻炼的医务人员鼻前庭病原菌的检出率较高,差异具有统计学意义（均P＜0.05）。43株病原菌中检出1株耐亚胺培南的肺炎克雷伯菌。医务人员检出的7株肺炎克雷伯菌对氨苄西林/舒巴坦、头孢唑林、呋喃妥因的耐药率均＞50.00%,对头孢噻肟与亚胺培南的耐药率分别为28.57%、14.29%;同期患者检出的11株肺炎克雷伯菌对呋喃妥因的耐药率为100.00%,对其他常用抗菌药物均敏感。医务人员检出的4株大肠埃希菌对氨苄西林的耐药率为75.00%,对庆大霉素、妥布霉素、左氧氟沙星、环丙沙星及复方磺胺甲口恶唑的耐药率均为50.00%,而同期患者检出的6株大肠埃希菌对大部分常用抗菌药物均耐药。结论长期工作在ICU的医务人员鼻前庭病原菌定植率高,定期主动对医务人员鼻前庭病原菌定植情况进行筛查及监测,对预防医院感染,防止医务人员与患者之间的交叉传播具有重要意义。     

山区医院葡萄球菌属临床株的耐药性调查分析

目的探讨山区基层医院葡萄球菌属医院感染及耐药现状,采取有效措施控制医院感染。方法 2008年1月-2009年12月,从医院感染患者临床各类标本中分离出葡萄球菌属148株,对其进行了细菌鉴定、耐甲氧西林葡萄球菌(MRS)检测和K-B法药敏试验,并进行统计与分析。结果 148株葡萄球菌属分为6种,以金黄色葡萄球菌(SAU)分离率最高,占41.2%;其中耐甲氧西林金黄色葡萄球菌(MRSA)占SAU的41.0%;耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)占凝固酶阴性葡萄球菌的42.5%;甲氧西林敏感葡萄球菌耐药率明显低于MRS株。结论山区基层医院同样存在MRS感染,且比较严重,应采取切实措施,控制MRS的产生与流行。     

Molecular fingerprinting of meticillin-resistant Staphylococcus aureus strains isolated from patients and staff of two Iranian hospitals

Meticillin-resistant Staphylococcus aureus (MRSA) is an important cause of hospital-acquired infection. Methods for typing and epidemiological investigation of MRSA isolates have an important impact in detection of MRSA strains, source, transmission and control of these micro-organisms. The aims of this study were to study molecular diversity of MRSA isolates by randomly amplified polymorphic DNA (RAPD)-polymerase chain reaction (PCR), the surveillance efficacy of this method and determination of antibiotic resistance patterns of MRSA isolates. MRSA isolates were collected from clinical specimens and noses of 460 staff and inpatients admitted to Imam Khomeini and Paediatric Hospitals during a six-month period (2004-2005). Eighty MRSA strains, in which the presence of mecA gene had been confirmed by PCR, were subjected to RAPD-PCR using five primers and the results were summarised in a dendrogram to show the relationships between the test isolates. Antibiotic resistance patterns of MRSA isolates were also determined by disc agar diffusion method using 13 antibiotic discs according to Clinical and Laboratory Standards Institute guidelines. Forty-three RAPD-PCR profiles were detected. The test isolates were clustered into 18 taxa with 50% similarity, indicating the heterogeneity of our test isolates. MRSA isolates fell into 41 antibiotic resistance patterns. There was correlation between antibiotic resistance patterns and results of RAPD-PCR. Most of the MRSA isolates were multi-resistant.     

住院患者耐甲氧西林金黄色葡萄球菌定植与感染相关研究

目的调查住院患者耐甲氧西林金黄色葡萄球菌（MRSA）定植及感染的状况，分析MRSA定植与感染的关系。方法对某大医院神经内科住院患者在入院48h内及以后每周一、三、五采集鼻前庭标本，同时收集该期间住院患者送检临床标本中分离的MRSA菌株。以低频限制性位点聚合酶链反应（IRS—PCR）基因分型法对患者鼻前庭标本和临床标本分离的MRSA菌株进行同源性分析。结果共调查265例患者，MRSA定植者14例（5．28％），其中7例为入院前定植，7例为入院后定植；MRSA感染者10例（3．77％），其中8例的鼻前庭标本和临床标本均分离出MRSA，另2例仅临床标本分离出MRSA。IRS—PCR基因分型显示MRSA感染患者临床标本和鼻前庭标本分离出的MRSA具有很高的同源性。结论住院患者定植MRSA是发生MRSA医院感染的一个重要危险因素。     

耐甲氧西林金黄色葡萄球菌医院感染及社区感染的流行特点

目的了解住院患者中耐甲氧西林金黄色葡萄球菌(MRSA)医院感染及社区感染的流行特点,为积极预防和控制MRSA的感染与传播提供科学依据。方法 2008年7月1日-2010年12月31日,由专职人员每天根据细菌培养结果按照统一的方法到病房对患者进行前瞻性调查,2005年1月1日-2008年6月30日对金黄色葡萄球菌培养阳性住院患者进行回顾性调查。结果 MRSA医院感染率为0.10‰,入院患者中MRSA社区发病的感染率为1.40‰;医院感染中MRSA感染率为70.40%,显著高于社区感染感染率为46.04%(P<0.001);MRSA感染主要发生在重症监护病房(ICU)、内科及干部病房,呼吸系统的感染;MRSA感染率最高的是ICU和干部病房,>80.0%,呼吸系统和泌尿系统的感染。结论金黄色葡萄球菌耐药状况在医院内形势依然严峻,预防与控制MRSA感染重点在ICU、内科及干部病房,主要发生在呼吸系统的感染。     

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.     

耐甲氧西林金黄色葡萄球菌感染的流行病学及耐药性研究

目的探讨城市中心城区耐甲氧西林金黄色葡萄球菌(MRSA)感染的流行病学及耐药性。方法采用回顾性调查方法,对医院2009年住院患者进行MRSA感染的统计分析。结果在2009年40 846份标本中,检出265株金黄色葡萄球菌,检出率为0.65%;265株金黄色葡萄球菌检出MRSA 229株,检出率为86.42%;MRSA229株中9株是院内MRSA感染,占3.93%;220株为社区MRSA感染,占96.07%;该菌株对临床常用10种抗菌药物的耐药率>60.00%,但对万古霉素的敏感率为100.00%。结论城市中心城区社区MRSA感染现状已相当严重,应当和地段医院或社区医院一起加强MRSA的预防及治疗工作。     

Frequent acquisition of multiple strains of methicillin-resistant Staphylococcus aureus by healthcare workers in an endemic hospital environment

Methicillin-resistant Staphylococcus aureus (MRSA) has been an endemic nosocomial pathogen at the VA medical center (VAMC) in Providence, Rhode Island since 1981. From 1985 to 1987, more than 30% of all unique S aureus isolates were methicillin resistant. To evaluate the frequency of acquisition of MRSA isolates by healthcare workers, we compared the antimicrobial susceptibility patterns, multilocus enzyme genotypes and plasmid profiles of isolates recovered from nasal and hand cultures from VAMC nurses and house staff on rotation at the VAMC with those of clinical isolates from patients at the VAMC and four other affiliated hospitals. Fifty-six percent of ward nurses cultured (n = 112) were colonized with S aureus, of which 65% was methicillin resistant. Six isolates of MRSA were identified on the initial culturing of house staff (n = 65); 16 MRSA isolates were recovered at the end of a four-week rotation (p less than .02). Phenotypic and genotypic analyses demonstrated that numerous distinct MRSA strains were recovered in the study period. The incidence of MRSA among clinical isolates at the VAMC and affiliated institutions was remarkably constant throughout the three-year study period. Moreover, despite regularly sharing resident physicians, interns and medical students, MRSA isolates were commonly recovered at the other university-affiliated hospitals. Our study failed to reveal evidence of significant interhospital transmission of MRSA isolates by healthcare workers. While healthcare workers may contribute to the dissemination of MRSA within institutions, they appear to be less important in spreading MRSA between institutions.     

Enterotoxin production by strains of Staphylococcus aureus isolated from clinical and non-clinical specimens with special reference to enterotoxin F and toxic shock syndrome.

Enterotoxin production by strains of Staphylococcus aureus isolated from clinical specimens of human and animal origin and from healthy human carriers was investigated. All nine patients admitted to hospital with symptoms of toxic shock syndrome (TSS) yielded enterotoxin-producing strains of S. aureus. Eight of these produced staphylococcal enterotoxin F (SEF). A significantly smaller proportion of strains (42% of 50 strains tested) isolated from other clinical specimens of hospitalized patients produced SEF. Production of SEF by strains isolated from clinical specimens of animal origin (48 strains) was not observed. Twenty-nine per cent of 24 S. aureus strains isolated from noses of hospital staff produced SEF. This result was not significantly different from that obtained from strains isolated from clinical specimens other than TSS. A similar percentage of strains isolated from healthy human carriers outside hospital produced SEF (25% of 24 strains tested). The results indicated that enterotoxin production, especially that of SEF, is associated with S. aureus isolated from patients suspected of TSS. There was no indication of an association between S. aureus isolated from other staphylococcal infections and SEF production. All strains were phage typed and 79% of the strains belonging to the international phage-group I produced SEF. All strains lysed by phage 187 were found to produce SEF.     

Enterotoxin production by strains of Staphylococcus aureus isolated from clinical and non-clinical specimens with special reference to enterotoxin F and toxic shock syndrome

Enterotoxin production by strains of Staphylococcus aureus isolated from clinical specimens of human and animal origin and from healthy human carriers was investigated. All nine patients admitted to hospital with symptoms of toxic shock syndrome (TSS) yielded enterotoxin-producing strains of S. aureus. Eight of these produced staphylococcal enterotoxin F (SEF). A significantly smaller proportion of strains (42% of 50 strains tested) isolated from other clinical specimens of hospitalized patients produced SEF. Production of SEF by strains isolated from clinical specimens of animal origin (48 strains) was not observed. Twenty-nine per cent of 24 S. aureus strains isolated from noses of hospital staff produced SEF. This result was not significantly different from that obtained from strains isolated from clinical specimens other than TSS. A similar percentage of strains isolated from healthy human carriers outside hospital produced SEF (25% of 24 strains tested). The results indicated that enterotoxin production, especially that of SEF, is associated with S. aureus isolated from patients suspected of TSS. There was no indication of an association between S. aureus isolated from other staphylococcal infections and SEF production. All strains were phage typed and 79% of the strains belonging to the international phage-group I produced SEF. All strains lysed by phage 187 were found to produce SEF.     

重症监护病房分离金黄色葡萄球菌的分子流行特征

目的了解某三甲医院重症监护病房(ICU)患者分离金黄色葡萄球菌的分子流行特点及其同源性,为有效控制医院感染的发生提供实验室依据。方法收集该院2013年3—8月ICU患者各类感染标本分离的62株金黄色葡萄球菌,采用PCR方法扩增7个管家基因并进行测序分析,采用多位点序列分型(MLST)技术获得菌株ST分型,对ST分型进行亲缘关系分析。结果 62株金黄色葡萄球菌均可以扩增出7个管家基因的特异性产物;共分为10个ST基因型,其中2个基因型为新发现的ST型(STn1和STn2),1个为国内新发现的ST型(ST675)。ST239是ICU患者分离的金黄色葡萄球菌主要ST型别,占74.20%,分布于6个ICU,分布范围最广;其次为ST5,分布于3个ICU。62株菌株在系统进化树上形成7个主要分支,检出耐甲氧西林金黄色葡萄球菌(MRSA)55株,占88.71%。结论医院ICU分离的金黄色葡萄球菌具有一定的同源性,并且少数型别表现出集中分布趋势。