广州市HIV感染者鼻腔携带MRSE与MSSE菌株的耐药谱及遗传特征比较

目的 比较广州市HIV感染者鼻腔携带耐甲氧西林表皮葡萄球菌(methicillin - resistant Staphylococcus epidermidis, MRSE)与甲氧西林敏感表皮葡萄球菌(methicillin sensitive Staphylococcus epidermidis, MSSE)的耐药谱及遗传特征。方法 于2017年6 - 8月,对广州市某医院艾滋病门诊1 001名HIV感染者鼻腔分离的表皮葡萄球菌进行药物敏感性试验及毒素基因、耐消毒基因、耐药基因检测。结果 分离鉴定出422株表皮葡萄球菌,包括309(73.22%)株MRSE,113(26.78%)株MSSE。MRSE菌株对青霉素、头孢西丁、红霉素、四环素、莫西沙星、复方新诺明这6种抗生素的耐药率高于MSSE,差异均有统计学意义。MRSE菌株的多重耐药率达77.99%,高于MSSE(36.28%)。MRSE菌株毒素基因pvl的检出率为9.06%,耐消毒基因qacA/B、smr的检出率分别为53.72%、11.33%,耐药基因aac(6’) - aph(2’)的检出率(63.75%)最高。结论 广州市HIV感染者鼻腔MRSE的检出率和多重耐药率高,MRSE耐药情况较MSSE严重;耐消毒基因qacA/B和耐药基因aac(6’) - aph(2’)的检出率高。     

耐甲氧西林凝固酶阴性葡萄球菌耐药基因检测

目的 了解耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)耐药基因流行病学状况.方法 对40株MRCNS进行了mecA、aac(6')/aph(2')、aph(3')-Ⅲ、ermA/B/C、tetM检测.结果 40株MRCNS mecA、aac(6')/aph (2")、aph(3')-Ⅲ、ermA/B/C、tetM基因阳性株分别为39、32、15、30、2株,阳性率分别为97.5%、80.0%、37.5%、75.0%、5.0%;其中同时检出mecA基因、aac(6')/aph(2")/或aph(3')-Ⅲ基因、ermA/B/C基因26株(65.0%).结论 65.0%MRCNS已同时携带mecA、aac(6')/aph(2")/或aph(3')-Ⅲ、ermA/B/C基因.     

下呼吸道多重耐药菌的感染及治疗

细菌对3种以上不同类抗菌药物耐药者即为多重耐（multi—drug resistant bacteria，MDR）。耐药菌及MDR的发生和发展是抗菌药物广泛应用，特别是无指征滥用的后果。革兰阳性多重耐药主要有耐甲氧西林金黄色葡萄球菌（MRSA），耐甲氧西林凝固酶阴性葡萄球菌（MRCNS），     

新生儿耐甲氧西林凝固酶阴性葡萄球菌败血症36例分析

2000～2003年我院经血培养确诊的新生儿败血症86例,其中耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)败血症36例(41.86%),现就其临床特点及耐药特征分析报告如下.     

耐甲氧西林葡萄球菌临床和耐药谱特点

感染患者分离的细菌中以革兰阳性球菌为多 ,其中耐甲氧西林葡萄球菌 (MRS)比例日趋升高 ,并已成为较难控制的致病菌。我们将临床分离的 39株MRS进行鉴定、分析 ,并对其感染的患者进行回顾性调查 ,以了解其临床和耐药性特点。1　材料与方法1 1　材料　选择我院住院患者分离的MRS菌株(每例患者仅选择 1株 ) ,其中耐甲氧西林金黄色葡萄球菌 (MRSA)计 9株 ,占 2 3 0 8% ,耐甲氧西林凝固酶阴性葡萄球菌 (MRCNS)计 30株 ,占 76 92 %。1 2　方法　临床分离菌株按NCCLS推荐标准方法分型、鉴定。MRS选择培养基中含 4 %NaCl,药敏试验用纸…     

251株凝固酶阴性葡萄球菌的分布及耐药性分析

目的 了解凝固酶阴性葡萄球菌(CNS)的耐药状况,为临床合理用药提供科学依据.方法 对从患者临床标本中分离的251株CNS进行耐药性分析.结果 251株CNS中甲氧西林敏感凝崮酶阴性葡萄球菌(MSCNS)检出率为12.75%;耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)检出率为87.25%;MRCNS对抗菌药物的耐药率显著高于MSCNS,未发现对万古霉素耐药和中介的菌株.结论 实验室应做好CNS的耐药性监测,及时掌握细菌耐药最新动态,为合理使用抗菌药物提供依据.     

耐甲氧西林凝固酶阴性葡萄球菌及糖肽类耐药的检测与分析

目的了解中日友好医院临床耐甲氧西林凝固酶阴性葡萄球菌（MRCNS）糖肽类耐药的流行情况和耐药机制,为MRCNS医院感染的预防与控制提供可靠依据。方法头孢西丁纸片法、mecA基因PCR检测MRCNS;万古霉素耐药确证试验筛选对万古霉素敏感性下降的凝固酶阴性葡萄球菌（CNS）,E-test法检测其MIC及多重PCR检测其van基因。结果CNS对头孢类、β-内酰胺类、氨基糖苷类、大环内酯类、克林霉素类抗菌药物耐药程度较高;52株CNS菌中头孢西丁纸片法与mecA基因检测MRCNS的符合率为96.2%,mecA基因阳性率为92.3%;256株CNS菌中筛选出4株异质性耐万古霉素葡萄球菌（VRS）,均为MRCNS,未检出vanA、vanB、vanC1及vanC2基因。结论对VRS和MRCNS进行有效的实验室检测与院内监测并采取有效措施预防与控制其传播是非常重要的。     

医院感染凝固酶阴性葡萄球菌的种类及耐药性分析

目的 探讨医院感染凝固酶阴性葡萄球菌(CNS)的种类及耐药性,为临床医师合理使用抗菌药物提供科学依据.方法 细菌培养鉴定严格按照《全国临床检验操作规程》,采用常规方法进行;药物敏感试验采用CLSI推荐的K-B法进行.结果 167株CNS中耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)检出率为43.1％,甲氧西林敏感凝固酶阴性葡萄球菌(MSCNS)检出率为56.9％;MRCNS对常用抗菌药物的耐药率明显高于MSCNS,所有CNS对糖肽类抗菌药物100.0％敏感.结论 临床医师应规范使用抗菌药物,以延缓细菌耐药性增长趋势,控制医院感染的暴发流行.     

分泌物分离的凝固酶阴性葡萄球菌耐药性及预防对策

目的 监测与分析医院住院患者2008-2011年感染性分泌物分离的凝固酶阴性葡萄球菌(CNS)耐药性,探讨感染控制方案并制定相应的预防措施.方法 细菌培养和鉴定按照《全国临床检验操作规程》(第3版),采用常规方法进行;药敏试验采用CLSI推荐的K-B法,药敏结果采用CLSI 2008-2011年折点进行判断;万古霉素采用E-test试条进行检测;耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)检测采用头孢西丁法;采用WHONET5.4-5.5软件进行数据统计分析.结果 177株CNS中检出MRCNS 97株,检出率为54.8％ ;CNS对青霉素、红霉素、克林霉素的耐药率最高,均＞80.0％;对磺胺甲噁唑/甲氧苄啶耐药率＞60.0％;对氯霉素和利福平的耐药率较低,均≤4.0％;未发现对万古霉素、替考拉宁和利奈唑胺耐药菌株.结论 医院应严格按照卫生部制定的《抗菌药物临床应用管理办法》对抗菌药物的使用进行分级管理,临床医师应根据病原学检测结果对感染性疾病有针对性地进行治疗,以遏制和降低细菌耐药现象的产生和扩散.     

葡萄球菌属临床分布及耐药性监测

目的了解医院的耐甲氧西林金黄色葡萄球菌(MRSA)感染的临床分布及耐药性,为临床合理使用抗菌药物提供依据。方法菌种鉴定采用常规方法涂片、革兰染色镜检、触酶试验、血浆凝固酶试验确认及ATB细菌鉴定系统对标本进行细菌鉴定,药物敏感试验采用纸片扩散(K-B)法。结果 2008年1月-2010年12月共分离金黄色葡萄球菌144株占70.9%,凝固酶阴性葡萄球菌(CNS)59株占29.1%;临床科室分布,ICU金黄色葡萄球菌71株占35.0%,CNS 30株占14.8%,呼吸内科金黄色葡萄球菌52株占25.6%,CNS 23株占11.3%,皮肤科金黄色葡萄球菌21株占10.3%,CNS 6株占3.0%等。结论监测葡萄球菌属的耐药状况,准确检出耐甲氧西林葡萄球菌(MRS),尤其是MRSA,在指导临床合理用药,隔离治疗感染者,预防MRS医院传播等方面具有重要作用。     

1 178名健康人群耐甲氧西林凝固酶阴性葡萄球菌的携带及耐药性

目的 调查广东省部分健康人群的凝固酶阴性葡萄球菌(CoNS)和耐甲氧西林凝固酶阴性葡萄球菌(MRCoNS)携带情况,并分析MRCoNS菌株的耐药性。方法 对研究对象进行问卷调查和鼻拭子采样,检测MRCoNS菌株的耐药表型和耐药基因,率的比较分析方法采用χ2检验。结果 1 178名研究对象中;CoNS携带率为46.4%;MRCoNS携带率为18.5%。近一个月门诊看病史、下班回家立即洗澡频率对人群MRCoNS携带影响有统计学意义(P均<0.05)。MRCoNS及其亚型对红霉素、四环素、克林霉素、复方新诺明耐药率较高,主要携带四环素耐药基因 tetK 和红霉素耐药基因是 ermC 。结论 健康人群MRCoNS携带率和耐药率均偏高,需加强人群卫生防护工作。     

Transfer of gentamicin resistance between coagulase-negative and coagulase-positive staphylococci on skin.

The transfer of gentamicin resistance between a coagulase-negative S. hominis strain and various coagulase-positive S. aureus strains on human and murine skin in the absence of a selective agent is described. Transfer occurs at higher frequency on skin than in broth. Skin transfer may account for the apparently explosive occurrence of gentamicin resistant staphylococci in hospitals.     

Airborne dispersal as a novel transmission route of coagulase-negative staphylococci: interaction between coagulase-negative staphylococci and rhinovirus infection.

OBJECTIVE: To investigate whether rhinovirus infection leads to increased airborne dispersal of coagulase-negative staphylococci (CoNS). DESIGN: Prospective nonrandomized intervention trial. SETTING: Wake Forest University School of Medicine, Winston-Salem, North Carolina. PARTICIPANTS: Twelve nasal Staphylococcus aureus-CoNS carriers among 685 students screened for S. aureus nasal carriage. INTERVENTIONS: Participants were studied for airborne dispersal of CoNS in a chamber under three conditions (street clothes, sterile gown with a mask, and sterile gown without a mask). After 2 days of pre-exposure measurements, volunteers were inoculated with a rhinovirus and observed for 14 days. Daily quantitative nasal and skin cultures for CoNS and nasal cultures for rhinovirus were performed. In addition, assessment of cold symptoms was performed daily, mucous samples were collected, and serum titers before and after rhinovirus inoculation were obtained. Sneezing, coughing, and talking events were recorded during chamber sessions. RESULTS: All participants had at least one nasal wash positive for rhinovirus and 10 developed a symptomatic cold. Postexposure, there was a twofold increase in airborne CoNS (P = .0004), peaking at day 12. CoNS dispersal was reduced by wearing a gown (57% reduction, P < .0001), but not a mask (P = .7). Nasal and skin CoNS colonization increased after rhinovirus infection (P < .05). CONCLUSIONS: We believe this is the first demonstration that a viral pathogen in the upper airways can increase airborne dispersal of CoNS in nasal S. aureus carriers. Gowns, gloves, and caps had a protective effect, whereas wearing a mask did not further reduce airborne spread.     

患儿感染耐甲氧西林凝固酶阴性葡萄球菌耐药性及基因分型研究

目的调查研究患儿感染耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)耐药性及基因分型,为MRCNS感染的抗菌药物选择、NRCNS感染的防治提供科学参考依据。方法收集2011年1月-2016年12月期间儿科164例感染性疾病患儿送检的164份临床标本,行菌株培养、表型筛选;采用标准琼脂倍比稀释法对MRCNS进行抗菌药物最低抑菌浓度(MIC)检测,确定耐药状况;采用聚合酶链反应(PCR)扩增基因检测葡萄球菌染色体mec基因盒(SCCmec)各分型。结果 164份标本中共检出78株MRCNS,检出率为47.56%;其中耐甲氧西林表皮葡萄球菌(MRSE)35株占44.87%,耐甲氧西林溶血性葡萄球菌(MRSH)19株占24.36%,耐甲氧西林人葡萄球菌(MRSHo)10株占12.82%;MRCNS对青霉素、头孢哌酮、头孢曲松、头孢噻肟、亚胺培南均完全耐药,耐药率为100.00%,对红霉素、阿奇霉素、克林霉素的耐药率均>80.00%,对万古霉素完全敏感,耐药率为0;MRCNS的SCCmec基因分型Ⅰ~Ⅵ型有检出,Ⅶ~Ⅷ型未检出,其中Ⅲ型基因38株占48.72%,混合型19株占24.36%,7株IV型占8.97%。结论患儿感染性疾病时MRCNS检出率较高,MRCNS对临床常用的多种抗菌药物耐药率高,具有多药耐药性,MRCNS所携带的SCCmec基因型主要为Ⅲ型及混合型,以上基因可能与MRCNS耐药关系密切。     

Isolation and molecular characterization of methicillin-resistant coagulase-negative staphylococci from nasal flora of healthy humans at three community institutions in Rio de Janeiro City

We describe the isolation and molecular characterization of methicillin-resistant coagulase-negative staphylococci (MRCNS) from the nasal flora of healthy humans from three institutions located in Rio de Janeiro City. Swabs were obtained from the nares of students attending a non-residential public school and adults from two military quarters. Isolates of staphylococci were tested for the presence of the mecA gene by hybridization with a specific probe. S. epidermidis was the most frequent MRCNS (38 of the total 45 CNS isolated). Twenty-five percent of nasal staphylococcal carriers studied were colonized with MRCNS. Pulsed-field gel electrophoresis (PFGE) of SmaI-digested genomic DNA was carried out to study the clonality of the methicillin-resistant S. epidermidis (MRSE) isolates. In addition to cross-colonization among individuals belonging to the same institution, familial cross-colonization appeared to contribute to the spread of the methicillin-resistant isolates among two inter-communicable institutions. Indeed, the wide genomic diversity among the MRSE flora suggests that the spread of the mecA gene among these isolates might also have occurred via horizontal transmission. Despite the limited number of institutions analysed, it is reasonable to conclude that our data do not represent a situation unique to the three organizations but may reflect other communities in Rio with respect to transmission of MRCNS.     

创伤患者凝固酶阴性葡萄球菌的分布及耐药性分析

目的探讨凝固酶阴性葡萄球菌(CNS)在创伤患者中的感染现状,并对其耐药性进行分析。方法回顾分析医院2005年1月-2009年12月分离自创伤患者伤口分泌物的葡萄球菌属,进行耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)和甲氧西林敏感凝固酶阴性葡萄球菌(MSCNS)的检测和分析。结果在创伤患者伤口分泌物的1068株葡萄球菌属分离株中,CNS 510株,占47.75%,其中表皮葡萄球菌377株,居首位,其次为溶血葡萄球菌120株,且溶血葡萄球菌的分离率有逐年增高的趋势;MSCNS 283株,MRCNS 227株,亦呈逐年增高的趋势;CNS对多种常用抗菌药物呈高度耐药(>50.00%),尤其对临床常用的三代头孢菌素及碳青霉烯类抗菌药物的耐药性呈明显增加的趋势,而对新近应用于临床的奈替米星、米诺环素的耐药率则较低,万古霉素对CNS仍保持100.00%的抑菌活性。结论创伤患者的CNS分离率逐年增高且呈多药耐药的趋势,临床应给予足够重视,根据药敏结果筛选适当的抗菌药物。     

A study of coagulase-negative staphylococci with reference to slime production, adherence, antibiotic resistance patterns and clinical significance.

Two hundred and fifty-one strains of coagulase-negative staphylococci (CNS) isolated from patients in hospital and the community were investigated for slime production and adherence as indicators of pathogenicity. Staphylococcus epidermidis formed 68.5% (126) of the isolates of CNS from blood and central venous catheter (CVC) tips, of which 46.0% (58) were slime-positive and adherent. Clinically significant infections were associated with 55.2% (32) of the slime-positive adherent strains isolated and 11.1% (four) of slime-negative non-adherent strains of S. epidermidis. For other species of CNS isolated from blood and CVC tips 74.1% (43) were slime negative non-adherent and 18.6% (eight) of these were considered clinically significant isolates while none of the slime positive adherent strains were associated with a clinically significant infection. Slime production and adherence were not characteristic properties of CNS causing community-acquired urinary tract infection or colonizing the nasal mucosa. It is concluded that slime production and adherence had a limited role in the differentiation between clinically significant and contaminant strains isolated from blood cultures; however, the absence of slime and adherence in isolates of S. epidermidis suggested a lack of pathogenicity.     

Species identification, antibiotic sensitivity and slime production of coagulase-negative staphylococci isolated from clinical specimens

Two hundred and seventy-five consecutive clinical isolates of coagulase-negative staphylococci, including strains associated with disease, contaminants and skin colonizers, were speciated, tested for slime production and for their sensitivity to a range of antibiotics. Staphylococcus epidermidis was the most commonly identified species, comprising 63% of all isolates. Slime production was detected in half the strains of Staph. epidermidis, Staph. haemolyticus and Staph. saprophyticus but was rare in other species. Most Staph. haemolyticus strains and approximately half of the Staph. epidermidis strains were resistant to five or more antibiotics. A significant association was found between slime production and multiple antibiotic resistance. For catheter-associated strains, clinical relevance was predictable by species i.e. Staph. epidermidis. Multi-resistant slime-positive Staph. haemolyticus strains, although infrequently associated with disease, were common skin colonizers, presumably acquired from the hospital environment. We describe a practical and inexpensive scheme for the speciation of human coagulase-negative staphylococcal isolates.