碳青霉烯类耐药肺炎克雷伯菌的毒力因子、荚膜血清型与生物膜形成的关系

Relationship between Virulence Gene,Capsule Serotype and Biofilm Formation of Carbapenem-resistant Klebsiella Pneumoniae Strains

目的:分析临床分离的碳青霉烯类耐药肺炎克雷伯菌毒力因子、荚膜血清型及其与生物膜形成的关系。方法:收集2011–2016年华中科技大学协和深圳医院肺炎克雷伯菌临床菌株,利用微量肉汤稀释法测定其对美罗培南和亚胺培南最低抑菌浓度(MIC)筛选耐碳青霉烯临床菌株,采用聚合酶链反应(PCR)技术扩增毒力基因(rmpA、rmpA2、wabG、uge、fimH、mrkD、ycf、wcaG、entB、iron、hly、cnf、aerobactin)、荚膜血清型(K1、K2、K5、K20、K54、K57)以及采用结晶紫染色法检测肺炎克雷伯菌生物膜形成能力。结果:共筛选出41株耐碳青霉烯临床菌株,结晶紫染色后肺炎克雷伯菌的平均OD550值为1.07±0.37;肺炎克雷伯菌荚膜血清型别与生物膜形成无相关性,毒力因子单因素分析及多元线性回归分析结果显示,wabG、iron毒力因子与肺炎克雷伯菌生物膜形成相关。结论:耐碳青霉烯肺炎克雷伯菌携带wabG、iron毒力因子更易形成生物膜。

Objective To analyze the relationship between carbapenem-resistant Klebsiella pneumoniae virulence factor,capsule serotype and biofilm formation.Methods Clinical strains of Klebsiella pneumoniae in Huazhong University of Science and Technology Union Hospital from 2011 to 2016 were collected.The minimum inhibitory concentration(MIC) against meropenem and imipenem was determined by microbroth dilution method to select carbapenem-resistant clinical strains.The polymerase chain reaction(PCR) technology was used to amplify virulence genes(rmpA、rmpA2、wabG、uge、fimH、mrkD、ycf、wcaG、entB、iron、hly、cnf、aerobactin) and pod serotypes(K1、K2、K5、K20、K54、K57).The biofilm forming ability of Klebsiella pneumoniae was detected by crystal violet staining.Results A total of 41 carbapenem-resistant strains were screened.The average OD550 value of Klebsiella pneumoniae after crystal violet staining was 1.07 ± 0.37.There was no statistical significance between Klebsiella pneumoniae capsule serotype and biofilm formation.The results of single factor analysis and multiple linear regression analysis of virulence factors showed that wabG and iron virulence factors were related to the formation of Klebsiella pneumoniae biofilm.Conclusion Carbapenem-resistant Klebsiella pneumoniae was more likely to form biofilms with wabG and iron virulence factors.