不同基因型别纹带棒状杆菌耐药特点和生物膜形成能力分析

Drug resistance and biofilm formation abilities of Corynebacterium striatum with different genotypes

目的分析不同基因型别纹带棒状杆菌的药物敏感性和生物膜形成能力,为临床诊治纹带棒状杆菌相关感染提供实验室依据。方法收集2018年1月—2020年12月首都医科大学附属北京友谊医院临床分离的36株纹带棒状杆菌(21株分离自无菌体液样本、15株分离自清洁中段尿样本),进行多位点序列分型(MLST);采用琼脂稀释法检测36株纹带棒状杆菌对10种抗菌药物的敏感性,采用MTT法分析其生物膜形成能力。结果36株纹带棒状杆菌主要分离自免疫功能低下的老年患者,有9个ST型别,其中ST6(36.1%)和ST2(25.0%)为优势基因型别。36株纹带棒状杆菌均为多重耐药菌(MDR),仅对万古霉素和利奈唑胺100%敏感。ST2型菌株以四环素敏感株为主,ST6型菌株以庆大霉素和利福平敏感株为主。所有菌株均具有在聚苯乙烯表面形成生物膜的能力,其中ST2型菌株与其他型别菌株比较,普遍具有更强的生物膜形成能力(P<0.05)。结论不同基因型别的纹带棒状杆菌生物膜形成能力和药物敏感性存在差异,临床应合理选用抗菌药物,避免造成机会性感染和院内感染。

Objective To study the characteristics of drug susceptibility and biofilm formation ability of Corynebacterium striatum with different genotypes,and to provide a reference for clinical diagnosis and therapy.Methods Totally,36 isolates of Corynebacterium striatum were collected from January 2018 to December 2021,which included 21 isolates from sterile body fluid specimens and the other 15 isolates from clean middle urine specimens.Multilocus sequence typing(MLST)genotyping,drug susceptibility test(agar dilution method)to 10 agents and biofilm formation determination(MTT)were carried out.Results Totally,36 isolates of Corynebacterium striatum were isolated mainly from immuno-suppressed elder patients,9 genotypes were classified with MLST method,and ST6(36.1%)and ST2(25.0%)were the most popular genotypes.All the 36 isolates were multi-drug resistance(MDR)bacteria,and they were sensitive to vancomycin and linezolid(100%).Most ST2 isolates were sensitive to tetracycline,while most ST6 isolates were sensitive to gentamicin and rifampin.The biofilm formation determination showed that all the 36 isolates could form biofilm on the polystyrene surface,but the ST2 ones had stronger biofilm formation ability compared with the other genotypes(P<0.05).Conclusions Different genotypes of Corynebacterium striatum have different biofilm formation abilities and drug susceptibilities to commonly used antibiotics.In the process of clinical diagnosis and treatment,clinicians should pay more attention to the rational use of antibiotics,which will help to avoid opportunistic infections and nosocomial infections.