卡他莫拉菌临床分布及耐药性分析

目的分析卡他莫拉菌(MC)的临床分布特点及耐药现状,为抗感染治疗提供参考依据。方法收集医院2007年7月-2012年12月住院患者各种感染性标本,细菌培养和分离严格按照《全国临床检验操作规程》进行,采用法国生物梅里埃公司生产的VITEK-2Compact全自动微生物分析仪和配套鉴定试剂盒进行菌种鉴定;采用琼脂稀释法对抗菌药物进行敏感试验,并用头孢硝噻吩纸片检测β-内酰胺酶,数据统计应用WHONET 5.5软件处理分析。结果 55株MC在痰液和咽拭子中检出率最高,占74.5%,其次为耳分泌物占18.2%,眼结膜分泌物标本占7.3%;科室分布以儿科为主占50.9%,其次为呼吸科占21.8%;喹诺酮类抗菌药物对MC表现出较高的敏感性,左氧氟沙星为100.0%敏感,环丙沙星为98.2%,对阿莫西林/克拉维酸与克拉霉素保持着100.0%的抗菌活性,对氨苄西林的耐药率为92.7%。结论 MC不但可引起医院感染,而且可导致医院感染的暴发流行,因此医院务必要执行《抗菌药物临床应用管理办法》,重视MC的病原学检测。     

苏州地区下呼吸道感染患儿卡他莫拉菌感染及耐药性分析

了解苏州地区下呼吸道感染儿童卡他莫拉菌的感染情况及耐药性.     

聊城地区卡他莫拉菌耐药分析

目的 本研究对2016年-2019年聊城市人民医院和聊城市第二人民医院呼吸道感染患者来源的卡他莫拉菌进行了耐药分析.方法 按照临床实验室标本处理流程对标本进行分离培养,菌株通过VITEK MS全自动鉴定仪进行鉴定,并对卡他莫拉菌进行药物敏感性分析.结果 本研究的102例卡他莫拉菌分离株绝大多数菌株(96.36％)呈现β...     

中医院患者下呼吸道感染卡他莫拉菌耐药性分析

目的了解中医院患者下呼吸道感染卡他莫拉菌的分布与耐药性,为该疾病提供有效的治疗措施。方法对2009年1月-2013年12月1 304例下呼吸道感染患者的痰标本进行检测,观察下呼吸道卡他莫拉菌感染的分布,并对检出的卡他莫拉菌进行药敏试验和β-内酰胺酶检测。结果从痰标本中培养出1 932株病原菌,卡他莫拉菌居第3位,共检出216株,占11.2%;均来自216例下呼吸道患者的痰培养标本,卡他莫拉菌在第一、四季度分离最高,分别占31.0%、33.8%;191株β-内酰胺酶检测结果阳性,产β-内酰胺酶率88.4%;卡他莫拉菌对头孢唑肟、头孢吡肟、左氧氟沙星、头孢呋辛、加替沙星和阿莫西林/舒巴坦的耐药率均<10.0%;对氨苄西林、头孢克洛与磺胺甲噁唑/甲氧苄啶的耐药率较高,分别为75.9%、62.0%和58.3%。结论卡他莫拉菌是下呼吸道感染患者的主要病原菌;第一季度和第四季度的是卡他莫拉菌感染的高发季节;在下呼吸道卡他莫拉菌抗感染治疗中应充分考虑其耐药性,合理应用抗菌药物。     

儿童呼吸道卡他莫拉菌分离株产β-内酰胺酶情况和耐药性以及菌株BRO酶基因特征

目的研究儿童呼吸道卡他莫拉菌分离株产β-内酰胺酶情况和耐药性以及菌株BRO酶基因特征。方法选择2016年2月-2019年1月因呼吸道感染就诊且从痰液标本中分离得到卡他莫拉菌的患儿,测定抗生素敏感性、产β-内酰胺酶情况、BRO酶基因表达情况。结果产酶菌株对氨苄西林、阿莫西林、头孢克洛、头孢呋辛、头孢吡肟、左氧氟沙星、克拉霉素产生耐药的发生率高于非产酶菌株,BRO-1基因阳性菌株对氨苄西林、阿莫西林、头孢克洛、头孢呋辛、头孢吡肟、左氧氟沙星、克拉霉素产生耐药的发生率高于BRO-2基因阳性菌株;产酶菌株和非产酶菌株、BRO-1基因阳性和BRO-2基因阳性菌株均对亚胺培南敏感,未发生耐药。结论儿童呼吸道卡他莫拉菌产β-内酰胺酶比例高,且BRO-1基因阳性菌株的耐药性强于BRO-2基因阳性菌株。     

流感嗜血菌及黏膜炎莫拉菌的耐药性分析

目的探讨流感嗜血菌(HIN)和黏膜炎莫拉菌(MCA)的耐药现状,为临床治疗提供参考依据。方法细菌培养和分离严格按照《全国临床检验操作规程》进行;采用法国生物梅里埃公司VITEK-2Compact全自动微生物分析仪和配套鉴定试剂盒进行菌种鉴定;采用琼脂稀释法对抗菌药物进行敏感试验,并用头孢硝噻吩纸片检测β-内酰胺酶;数据统计应用WHONET 5.5版本软件处理分析。结果喹诺酮类抗菌药物对HIN表现出较高的敏感性,左氧氟沙星和莫西沙星均为100.0%敏感,环丙沙星为99.0%;阿奇霉素的敏感率最低,为4.8%;喹诺酮类抗菌药物对MCA表现出较高的敏感性,左氧氟沙星为100.0%敏感,环丙沙星为98.2%;对阿莫西林/克拉维酸与克拉霉素保持着100.0%的抗菌活性;阿莫西林的耐药率为92.7%。结论医院务必要执行《抗菌药物临床应用管理办法》,对感染患者必须参照药敏结果结合患者具体状况抗感染治疗。     

临床分离的卡他莫拉菌对抗菌药物敏感性分析

目的 探讨卡他莫拉菌(MC)的耐药现状,为临床治疗提供参考依据.方法 对临床分离的90株MC采用琼脂稀释法进行抗菌药物敏感试验,并用Nitrocefin纸片检测p内酰胺酶.结果 MC检出率最高的是儿科占56.7％,其次为呼吸内科占35.6％,肿瘤科占7.7％,MC产β-内酰胺酶率为90.0％;MC对氨苄西林的敏感率最低,仅8.9％;MC对阿莫西林/克拉维酸、左氧氟沙星和克拉霉素100.0％敏感.结论 临床医师应选用含β-内酰胺酶抑制剂的青霉素类,第二、三代头孢菌素或大环内酯类治疗MC引起的感染.     

引起呼吸道感染的卡他莫拉氏菌的检出及药敏试验

此文报告了2004年2月-2006年8月经临床确诊为呼吸道感染的患者共1827例,其中卡他莫拉氏菌235株,占12.8%。在235例卡他莫拉氏菌感染中,145例为COPD。对235株卡他莫拉氏菌进行药敏试验。结果表明其对青霉素、氨苄青霉素的耐药率达80%以上;对环丙沙星的耐药率达20.4%;对头孢曲松、头孢噻肟、优普同(头孢呱酮-舒巴坦钠)的耐药率分别为3.8%、5.1%及1.3%;对庆大霉素、丁胺卡钠的耐药率均为8.5%;235株卡他莫拉氏菌产β-内酰胺酶率为89.76%,应选用对β-内酰胺酶稳定的头胞菌素、氨基甙及喹诺酮类抗菌药物。     

儿童呼吸道卡他莫拉菌感染的防治

目的探讨卡他莫拉菌感染的初步防治.方法对2001年11月～2003年3月间,在金昌市区3家医院门诊及住院的6岁以下儿童,有呼吸道感染症状者,采集咽部分泌物及痰进行培养,观察并总结其呼吸道卡他莫拉菌感染的情况及临床特点.结果从呼吸道感染病人标本中培养出420株菌.其中,卡他莫拉菌128例,占30.5%,位于第1位,此菌感染多见于体质差的3岁以下儿童,以下呼吸道感染为多见,旦临床表现重,普遍对β-内酰胺类药物耐药.结论积极防治儿童营养性疾病,合理应用抗生素,对3岁以内儿童呼吸系统感染,临床表现重的应及时采集咽部分泌物及痰进行培养,一旦培养出卡他莫拉菌,就应选特效的β-内酰胺酶稳定剂药物治疗.     

Vaccines for Moraxella catarrhalis

Vaccine development for Moraxella catarrhalis is in the antigen identification stage. M. catarrhalis does not appear to synthesize secreted antigens such as exotoxins, nor does it appear to possess a carbohydrate capsule. Modified forms of these antigens are usually good vaccine components. There is some interest in whole bacterial cells and membrane fractions, but the search has largely focused on purified outer surface antigens. All of the present antigens have been selected based on the response seen in animals, although the antibody response seen in people exposed to the bacterium provides some guidance. The antibody response provides information related to the cross-strain preservation of epitopes and whether they are surface exposed. Antigens that elicit antibodies that have complement dependent bactericidal capacity, opsonophagocytic activity or interfere with one of the antigen's known functions such as adhesion or nutrient acquisition are particularly valued. In addition to examining the antibody response, some antigens have been evaluated in a murine pulmonary clearance model. Using these assays and model, several vaccine candidates have been identified. The antigens may be roughly classified by the function they serve the bacterium. One set appears to promote adhesion to host tissues and includes the hemagglutinins, ubiquitous surface protein A1 (UspA1), and possibly the CD protein. A second set is involved in nutrient acquisition. This set includes the lactoferrin binding protein A (LbpA) and lactoferrin binding protein B (LbpB), the transferrin binding protein A (TbpA) and transferrin binding protein B (TbpB), the CD and E porins, and the Catarrhalis outer membrane protein B (CopB). A third set is comprised of antigens involved in virulence and it includes lipooligosaccharide (LOS) and the ubiquitous surface protein A2 (UspA2). Antigens of unknown function, such as the 200K protein, may also be vaccine candidates. The antigens that are most suitable will be determined in clinical studies that are only beginning now.     

Nosocomial transmission clusters and risk factors in Moraxella catarrhalis

SUMMARYWe report an objective examination of nosocomial transmission events derived from long-term (10-year) data from a single medical centre. Cluster analysis, based on the temporal proximity of genetically identical isolates of the respiratory pathogen Moraxella catarrhalis, identified 40 transmission events involving 33 of the 52 genotypes represented by multiple isolates. There was no evidence of highly transmissible or outbreak-prone genotypes. Although most clusters were small (mean size 3.6 isolates) and of short duration (median duration 25 days), clustering accounted for 38.7% of all isolates. Significant risk factors for clustering were multi-bed wards, and winter and spring season, but bacterial antibiotic resistance, manifested as the ability to produce a beta-lactamase was not a risk factor. The use of cluster analysis to identify transmission events and its application to long-term data demonstrate an approach to pathogen transmission that should find wide application beyond hospital populations.     

An aerosol challenge mouse model for Moraxella catarrhalis

A simple, reproducible, and non-invasive mouse pulmonary clearance model for Moraxella catarrhalis via aerosol challenge was established. All of eight tested strains could be inoculated into mice at more than 10(5) colony-forming units (CFU)/lung with a challenge concentration of 1x10(9)-6x10(9) CFU/ml in a nebulizer. The number of bacteria retained at 6 h postchallenge was more than 10(4) CFU/lung while at 24 h postchallenge, approximate 10(3) CFU/ml or less remained in the lungs. A maximum of 100 mice could be challenged per aerosol exposure. The number of bacteria inoculated in the lungs could be adjusted by the bacterial challenge concentration, the exposure time, and the negative pressure. Lung tissue sections revealed that bacteria were evenly distributed in the lungs. Passive immunization significantly enhanced pulmonary clearance of the homologous strain in this model. These data indicate that this model will be useful for evaluating M. catarrhalis vaccine candidates and studying roles of immunity against M. catarrhalis.     

Potential impact of a Moraxella catarrhalis vaccine in COPD

Moraxella catarrhalis is the second most common cause of exacerbations in adults with COPD, resulting in enormous morbidity and mortality in this clinical setting. Vaccine development for M. catarrhalis has lagged behind the other two important causes of exacerbations in COPD, nontypeable Haemophilus influenzae and Streptococcus pneumoniae. While no licensed vaccine is currently available for M. catarrhalis, several promising candidate vaccine antigens have been identified and characterized and are close to entering clinical trials. Key steps that are required to advance vaccines for M. catarrhalis along the translational pipeline include standardization of assay systems to assess candidate antigens, identification of a reliable correlate of protection and expansion of partnerships between industry, academia and government to overcome regulatory hurdles. A vaccine to prevent M. catarrhalis infections in COPD would have a major impact in reducing morbidity, mortality and healthcare costs in COPD.     

UspA2 is a cross-protective Moraxella catarrhalis vaccine antigen

Moraxella catarrhalis (Mcat) is a key pathogen associated with exacerbations of chronic obstructive pulmonary disease (COPD) in adults and playing a significant role in otitis media in children. A vaccine would help to reduce the morbidity and mortality associated with these diseases. UspA2 is an Mcat surface antigen considered earlier as vaccine candidate before the interest in this molecule vanished due to sequence variability. However, the observation that some conserved domains are the target of bactericidal antibodies prompted us to reconsider UspA2 as a potential vaccine antigen.We first determined its prevalence among the COPD patients from the AERIS study, as the prevalence of UspA2 in a COPD-restricted population had yet to be documented. The gene was found in all Mcat isolates either as UspA2 or UspA2H variant. The percentage of UspA2H variant was higher than in any report so far, reaching 51%. A potential link between the role of UspA2H in biofilm formation and this high prevalence is discussed.To study further UspA2 as a vaccine antigen, recombinant UspA2 molecules were designed and used in animal models and bactericidal assays. We showed that UspA2 is immunogenic and that UspA2 immunization clears Mcat pulmonary challenge in a mouse model. In a serum bactericidal assay, anti-UspA2 antibodies generated in mice, guinea pigs or rabbits were able to kill Mcat strains of various origins, including a subset of isolates from the AERIS study, cross-reacting with UspA2H and even UspA1, a closely related Mcat surface protein.In conclusion, UspA2 is a cross-reactive Mcat antigen presenting the characteristics of a vaccine candidate.     

肺炎克雷伯菌耐药性分析及质粒介导的 AmpC酶基因型检测

目的了解肺炎克雷伯菌的耐药性和质粒介导的AmpC酶基因型。方法采用K-B法进行抗菌药物敏感试验,用酶提取物三维试验检测AmpC酶,用聚合酶链反应(PCR)产物测序确定AmpC酶基因型。结果产超广谱β-内酰胺酶(ESBLs)阳性率41.90%、AmpC酶阳性率0.95%、ESBLs AmpC酶阳性率2.86%;药敏试验结果显示,对青霉素类、头孢菌素类、酶抑制剂复合剂、氨曲南、氟喹诺酮类均有较高耐药,亚胺培南敏感率100.00%;AmpC酶阳性菌株为质粒介导DHA型AmpC酶。结论可见临床分离的肺炎克雷伯菌中已经出现产质粒介导AmpC酶菌株,其耐药基因可在同种或不同种传播。     

肺结核患者产超广谱β-内酰胺酶大肠埃希菌、肺炎克雷伯菌的感染及耐药性分析

目的调查本院肺结核病与非结核病患者大肠埃希菌、肺炎克雷伯菌产超广谱β-内酰胺酶(ESBLs)细菌的感染及耐药现状. 方法搜集肺炎克雷伯菌和大肠埃希菌下呼吸道感染共575株,ESBLs的检测用纸片扩散表型确证. 结果肺结核患者的肺炎克雷伯菌中产ESBLs菌株为34.9%、大肠埃希菌为60.5%;而非结核患者的ESBLs株感染率明显低,后者ESBLs株感染率分别为20.8%和48.0%,上述产ESBLs菌株对头孢菌素第一、二代以及青霉素类、四环素类、磺胺类和喹诺酮类呈高度耐受性,有38%～59%的产ESBLs对氨曲南和第三代头孢菌素耐药,但对氨基糖苷类和碳青酶烯类的敏感性较高. 结论肺结核患者继发下呼吸道感染中ESBLs的总检出率为56.2%,以大肠埃希菌为主,ESBLs菌广泛耐药,应高度重视产ESBLs株的检测和药物敏感性试验.