关注分子技术在临床微生物检验中的应用

Application of molecular techniques in clinical microbiological determination

本期"微生物分子诊断专题"精心组织了6篇文章,包括1篇综述和5篇专著。内容主要围绕临床常见的细菌、真菌和分枝杆菌感染等的诊断、治疗(耐药)、预防和控制问题,重点介绍了分子生物学技术在临床微生物标本的直接检测、基因分型、耐药基因研究、抗原制备及血清学诊断等方面的应用研究。血流感染是一种严重的全身感染性疾病,但血培养存在检验周期长、阳性率低等问题,应用分子生物学技术能够对血流感染中的常见或少见病原菌、分枝杆菌、苛养菌等进行快速鉴定及耐药分析,可以缩短检验周期。艰难梭菌是一种重要的医院感染病原菌,引起抗菌药物相关性腹泻,GeneXpert实时荧光定量聚合酶链反应(PCR)能够直接检测粪便标本中的艰难梭菌,具有快速、操作简便等优点。光滑念珠菌可引起血流感染等多种感染,且耐药性强,是医院感染中常见的侵袭性真菌,微卫星多态性分析法简便快速,分辨力高于多位点序列分析(MLST),可作为临床实验室光滑念珠菌基因分型方法。近年来白念珠菌对唑类抗真菌药的耐药性有增高趋势。"白念珠菌对唑类耐药的机制和生物膜相关基因的表达"一文提示ERG11基因的过度表达为白念珠菌对唑类耐药的重要机制。菌丝细胞壁蛋白HWP1基因的高表达与白念珠菌生物膜形成相关。肺炎克雷伯菌对碳青霉烯类耐药的主要机制是产生质粒介导的2型肺炎克雷伯菌碳青霉烯酶(KPC-2),"同源重组敲除临床肺炎克雷伯菌质粒blaKPC-2基因"一文建立的λred同源重组法能可靠敲除其质粒上的blaKPC-2,为进一步研究blaKPC-2在肺炎克雷伯菌对碳青霉烯类药物耐药中所起的作用奠定基础。"结核分枝杆菌rdESA7-6抗原在耻垢分枝杆菌中的制备及其血清学诊断研究"一文研究制备的结核分枝杆菌融合蛋白-6用于结核病血清学检测具有较好的敏感性和特异性,可用于结核病患者的血清学诊断。

We carefully organized 6 manuscripts,including 1 review and 5 research papers for the molecular microbiology diagnosis special issue,mainly about the diagnosis,treatment （resistance ）,prevention and control of clinical common bacterium,fungus and mycobacterium infections.The special issue focuses on the application research of molecular biology techniques in the direct detection of clinical specimens,genotyping,resistance gene research, antigen preparation,serological diagnosis and so on.Blood stream infection is a serious infectious disease,but blood cultures have the problem with long turn-around-time and low positive rate.The application of molecular biology techniques can be used to the detection of common or rare pathogenic bacteria,mycobacteria,fastidous bacteria for rapid identification and drug resistance analysis in the blood stream infection,which can shorten the turn-around-time. Clostridium difficile is a kind of important nosocomial infection pathogen which can cause antimicrobial-associated diarrhea. GeneXpert real-time fluorescence quantitation polymerase chain reaction （PCR ） can directly detect Clostridium difficile infection and has the advantages of rapid detection,simple operation and so on.Candida glabrata can cause blood stream infection and other infections.It is a common invasive fungus in nosocomial infection with strong drug resistance.Microsatellite polymorphism offers a simple and rapid method for genotyping with resolution,which is higher than multilocus sequence typing （MLST）.Therefore,microsatellite polymorphism can be the preferred choice for Candida glabrata genotyping in laboratory.In recent years,Candida albicans azole resistance has increasing trend.The expression ofgenes related to azole resistance and biofilm in Candida albicans suggests that ERG1 1 gene over expression for Candida albicans is an important mechanism of azole resistance.High expression of HWP1 genes is associated with Candida albicans biofilm formation.The carbopenem resistance mechanism of Klebsiella pneumoniae is mainly producing plasmid-mediated Klebsiella pneumoniae carbopenem 2 （KPC-2 ）.Homologous recombination knockout blaKPC-2 gene in clinical isolates of Klebsiella pneumonia establishes lambda red homologous recombination method of knocking out its＆amp;nbsp;drug-resistant gene blaKPC-2 on plasmid contained by clinical Klebsiella pneumoniae drug-resistant strains reliably,which is helpful to further study on the carbopenem resistance mechanism of Klebsiella pneumoniae.On Preparation and serology diagnosis research ofrecombinant Mycobacterium smegmatis expressing rd ESAT-6 ofMycobacterium tuberculosis, the fusion proteins of Mycobacterium tuberculosis are successfully prepared in this study.The fusion protein has good specificity and sensitivity for the serological diagnosis among tuberculosis patients.