无菌体液分离的肺炎克雷伯菌耐药及毒力因子研究

Study on Drug Resistance and Virulence Factors of Klebsiella Pneumoniae Isolated from Sterile Body Fluids.

目的分析无菌体液分离的肺炎克雷伯菌(Klebsiella pneumoniae isolated from sterile body fluids,SBF-KP)的分布、耐药性及毒力因子的携带情况。方法收集从无菌体液分离的83株肺炎克雷伯菌,MALDI-TOF质谱仪进行菌株鉴定,Vitek-2compact系统进行药敏试验,黏液丝试验检测菌株高黏液表型,对菌株荚膜型及毒力基因进行PCR扩增和基因测序。结果无菌体液中,脓液中的肺炎克雷伯菌的检出率最高,其次是腹腔积液,分别为47.0%(39/83)和21.7%(18/83);SBF-KP对复方新诺明、氨曲南、环丙沙星、头孢他啶、替卡西林/克拉维酸、左旋氧氟沙星耐药率较高,大于20%,对替加环素、阿米卡星、碳青霉烯类药物仍有较高活性;SBF-KP荚膜型以K1、K2型为主,阳性率分别为39.8%(33/83)和13.3%(11/83);SBF-KP高黏液型阳性率为57.9%(48/83),高黏液型菌株中K1、K2型分别占45.8%(22/48)和18.8%(9/48);entB、fimH、uge、wabG、ureA、ycf毒力基因检出率最高,均大于98.0%;脓液与其他无菌体液分离的肺炎克雷伯菌在高黏液表型、rmpA、aerobactin、kfuB检出率方面比较差异有统计学意义(P<0.05)。结论SBF-KP对临床常用药物呈不同程度耐药,对阿米卡星、替加环素、碳青霉烯类药物有较好的药物敏感度;且SBF-KP菌株携带多种毒力因子,荚膜型以K1型、K2型为主,提示临床应进一步加强耐药监测,结合药敏合理选用抗生素,以提高疗效及减少高毒力和高耐药菌株的传播和流行。

Objective To analyze the clinical distribution,drug resistance and virulence factorsof Klebsiella pneumoniae isolated from sterile body fluids(SBF-KP).Methods The 83 strains of Klebsiella pneumoniae were isolated from sterile body fluids.The strains were identified by MALDI-TOF,and antimicrobial susceptibility testing was carried out by Vitek-2 compact.The HM phenotype of Klebsiella pneumoniae was determined by string test.The capsular serotypes and virulence genes of Klebsiella pneumoniae were analyzed by PCR and sequence alignment.Results The detection rate of Klebsiella pneumoniae isolated from pus was the highest,and the next was ascites,accounting for 47.0%and 21.7%,respectively.The drug resistance rates of SBF-KP to compoundsulfamethoxazole,aztreonam,ciprofloxacin,ceftazidime,levofloxacin and ticarcillin/clavulanic acid were relatively high,all of which were more than 20%;SBF-KP still maintained high activity against tigecycline,amikacin and hydrocarbon enzytenes.The K1 and K2 were dominant among the capsular serotypes of SBF-KP,and the positive rates were 39.8%and 13.3%,respectively.The positive rate of the HM phenotype of SBF-KP was 57.9%(48/83),and most of the hypermucoviscous SBF-KP strains belonged to K1(45.8%,22/48)or K2(18.8%,9/48)capsular serotypes.The detection rates of entB,fimH,uge,wabG,ureA,ycf,were higher in virulence genes,all above 98.0%.There wasa significant difference in the detection rate of HM phenotype,rmpA,aerobactin and kfuB between SBF-KP isolated from pus and other aseptic body fluids(P<0.05).Conclusion SBF-KP showed varying degrees of drug resistance to antimicrobial agents,and the strains still maintained high activity against tigecycline,amikacin and hydrocarbon enzytenes.The strains carried a variety of virulence genes,and K1/K2 capsular serotypes were the predominant serotypes.It suggests that we should further strengthen the monitoring of drug resistance and rationally select antibiotics in combination with drug sensitivity in order to improve the efficacy and reduce the spread and prevalence of hypervirulent and resistant strains.