肝脓肿肺炎克雷伯菌血清分型及毒力基因研究

Investigations on serotyping and virulence genes of Klebsiella pneumoniae isolated from patients with liver abscess

目的探讨肝脓肿相关肺炎克雷伯菌耐药性、血清型和毒力基因分布。方法收集75株肝脓肿患者临床分离肺炎克雷伯菌,采用Vitek 2系统检测耐药性;PCR法检测血清型及毒力基因分布情况。结果 75株肝脓肿肺炎克雷伯菌对哌拉西林耐药率为16%,对复方磺胺甲噁唑的耐药率为4%,对头孢菌素类、氨基糖苷类等多种抗菌药物敏感。血清型分布以K1型(62.7%)为主,其次为K2型(21.3%),其他型别K5、K20、K54及K57均占2.7%,4株(5.3%)未分型。毒力基因以rmp A和aerobactin检出率最高,分别达98.7%和97.3%,其次为kfu(68%)、wca G(66.7%)和all S(57.3%)。K1血清型菌株中以rmp A、wca G、aerobactin、kfu和all S 5种毒力基因同时携带为主,占83%;K2、K20和K57型菌株的主要携带模式为rmp A+aerobactin;K5型为rmp A+aerobactin+kfu;K54型为rmp A+aerobactin+wca G。结论肝脓肿相关肺炎克雷伯菌对多种抗菌药物敏感,K1、K2型是主要血清型,毒力基因rmp A和aerobactin检出率最高,K1血清型毒力基因检出种类最多。

Objective To investigate the epidemiological distribution of antimicrobial resistance,serotyping and virulence genes of Klebsiella pneumoniae causing liver abscess.Methods A total of 75 strains of Klebsiella pneumoniae were isolated from the patients with liver abscess. The antibiotics susceptibility was identified with Vitek 2 system and serotypes and virulence genes were detected using polymerase chain reaction.Results Of all the 75 strains of Klebsiella pneumoniae,the antimicrobial resistant rates to piperacillin was16% and 4% to trimethoprim and sulphame-thoxazole,but all were sensitive to cephalosporins,aminoglycosides and a variety of other antibiotics. The distribution of serotypes were mainly K1,accounting for 62.7% followed by K2（ 21.33%）,the rest were K5,K20,K54 and K57（ all were 2.7%）,and 4（ 5.3%） strains were untypable. Virulence genes rmp A and aerobactin showed higher prevalence（ 98.7% and 97.3%,respectively） followed by kfu（ 68%）,wca G（ 66.7%） and all S（ 57.3%）. The 5 virulence genes rmp A,wca G,aerobactin,kfu and all S could be found simultaneously in nearly all the K1 serotype with positive rate of 83%. Rmp A＋aerobactin was the predominant carrying mode in K2,K20 and K57 serotype,rmp A＋aerobactin＋kfu was in K5 serotype,and rmp A＋aerobactin＋wca G was in K54 serotype.Conclusion Klebsiella pneumoniae strains isolated from liver abscess patients should be sensitive to multiple antibiotics. The primary capsular serotypes were K1 and K2. Virulence genes rmp A and aerobactin showed higher prevalence,and the highest detection rates of virulence genes were found in K1 serotype.