血液分离肺炎克雷伯菌毒力基因与耐药性研究

目的 比较分析血液分离的高黏液性和非高黏液性肺炎克雷伯菌的毒力基因、抗菌药物耐药性和临床特征。方法 收集本院2015 年1 月-2016 年12 月血液标本分离的肺炎克雷伯菌144 株；采用VITEK-2 Compact 全自动微生物鉴定仪进行鉴 定；黏液丝试验检测高黏液表型；PCR 检测分离株主要荚膜型和毒力基因；KB 纸片扩散法对抗菌药物进行敏感性测定；SPSS 17.0 软件对数据进行分析。结果 收集的144 株肺炎克雷伯菌中，高黏液性菌株共31 株(21.53%)，以K1、K2 型多见，rmpA、 icuA、iroN、ybtS 和allS 基因在高黏液性菌株中的比例均显著高于非黏液性菌株(P<0.01)；高黏液性菌株对测定抗菌药物的耐药 性除氨苄西林外均低于非黏液性菌株，尤其是对头孢菌素类、亚胺培南和环丙沙星，具有显著性差异(P<0.05)；与非黏液性菌 株相比，高黏液性菌株血流感染更容易引起肝脓肿(P<0.05)，而两类细菌在致死率方面无明显统计学差异(P>0.05)。结论 血流 感染分离的高黏液性肺炎克雷伯菌较非黏液性肺炎克雷伯菌，含有更多的毒力基因，但药物敏感性较高，高黏液性肺炎克雷伯 菌败血症易发肝脓肿，临床应加强监控。

Detection of virulence genes and resistance against antibacterial drugs of Klebsiella neumoniae isolated from blood

Objective To investigate the virulence genes, resistance against antibacterial drugs and clinical features of bacteremia caused by hypermucoviscous and non-hypermucoviscous K. pneumoniae. Methods From January 2015 to December 2016, a total of 144 non-repetitive K. pneumoniae were isolated from blood. Bacteria were identified by the VITEK-2 Compact identification system. Hypermucoviscosity phenotype was determined by a string test. Capsular serotype and virulence genes were identified by polymerase chain reaction. Susceptibility to antibacterial drugs was determined by the standard disk diffusion method. Data were analyzed by the SPSS 17.0 software. Results Of the 144 K. pneumoniae isolates, 31 (21.53%) isolates produced a positive string test and K1 and K2 were more common. HmKP had higher proportions of rmpA, icuA, iroN, ybtS, and allS genes than non-HmKP (P<0.01). Except ampicillin, the resistance against antibacterial drugs of the HmKP was lower than that of non-HmKP, especially to cephalosporins, imipenem and ciprofloxacin (P<0.05). Compared to non-HmKP, HmKP caused bacteremia easily in patients with liver abscess (P<0.05), but there was no significant difference in the lethal rate between these two kinds of K. pneumoniae (P>0.05). Conclusion Compared to non-HmKP, HmKP isolated from blood contained more virulence genes, and were more susceptible to antibacterial drugs. Liver abscess was easily developed in patients of bacteremia caused by HmKP, which should be monitored more