下呼吸道感染铜绿假单胞菌产绿脓菌素及生物膜形成能力与耐碳青霉烯类抗菌药物相关性分析

Analysis on the relevance of pyocyanin production and form biological membrane formation and carbapenems in Pseudomonas aeruginosa causing low respiratory tract infections

目的探讨下呼吸道感染铜绿假单胞菌的绿脓菌素分泌水平、生物膜形成能力与碳青霉烯类药物耐药性关系,为临床抗感染治疗提供依据。方法收集2013年1-6月从患者痰液中分离到的60株铜绿假单胞菌,菌种鉴定采用VITEK-2全自动微生物分析仪;药敏测定采用K-B法;通过96孔板生物膜形成试验分析菌株生物膜形成能力;绿脓菌素通过氯仿萃取法测定;采用随机扩增多态性DNA法进行耐菌株的基因分型。结果 60株铜绿假单胞菌对亚胺培南的耐药率高达41.7%,对头孢吡肟和哌拉西林/他唑巴坦的耐药率较低,均为16.7%,25株亚胺培南耐药菌株在绿脓菌素产生及生物膜形成能力上要明显高于敏感株;25株耐药菌株分为8个基因型。结论产绿脓菌素和生物膜形成能力强的铜绿假单胞菌对碳青霉烯类药物耐药率高,临床不宜选用该类药物进行抗感染的经验治疗。

OBJECTIVE To explore the relationship among pyocyanin production ,biofilm formation and drug resist‐ance to carbapenem in Pseudomonas aeruginosa isolating from lower respiratory tract so as to provide basis for clinical anti‐infection therapy .METHODS A total of 60 P .aeruginosa were isolated from the sputum of the pa‐tients from Jan .to Jun .2013 .The species were determined through VITEK‐2 automated system .K‐B method was used for the antimicrobial susceptibility testing .Pyocyanlysin level and biofilm formation were examined by chloroform extraction method and 96‐well microtiter dish biofilm formation assay , respectively . The resistant strains genotyping were established by using random amplified polymorphic DNA fingerprinting .RESULTS The drug resistance rate of P .aeruginosa against imipenem was over 41 .7% ,however ,they were less resistant to cefepime and piperacillin/tazobactam with the rate of only 16 .7% for both .The 25 imipenem‐resistant strains were superior in producing pyocyanin and forming biofilm to the sensitive strains .Moreover ,the 25 strains can be further divided into 8 genotypes .CONCLUSION P .aeruginosa which were good at producing pyocyain and form‐ing biofilm were highly resistant to carbepenems ,hence carbepenems are not proper for treating infections in clini‐cal practice .