淮安市56株临床分离肺炎克雷伯菌耐药性和分子分型特征

Drug resistance and molecular characteristics of 56 clinical isolates of Klebsiella pneumoniae collected from pathogen identification network in Huai'an

目的了解淮安市临床分离肺炎克雷伯菌的耐药特征以及分子分型特点。方法 2018年1—6月,收集国家致病菌识别网络淮安市各哨点医院从临床标本中分离的肺炎克雷伯菌株,以拉丝试验测定分离菌株的黏液表型,以微量肉汤稀释法测定菌株对24种常用抗生素的耐药性,PCR检测荚膜血清型、毒力基因和碳青霉烯类耐药基因,利用脉冲场凝胶电泳进行分子分型。结果共收集临床分离肺炎克雷伯菌56株,高毒力肺炎克雷伯菌(hvKP)占55.36%,经典肺炎克雷伯菌(cKP)占44.64%。菌株多来自脓肿液(26.79%)、痰液(41.07%)。总耐药率为66.07%,多重耐药菌占58.93%,ESBLs菌株占17.86%,耐碳青霉烯类抗生素(美罗培南、亚胺培南)菌株占35.71%,3株为多粘菌素耐药菌株。除氯霉素、吉米沙星外,高毒力肺炎克雷伯菌(hvKP)MIC50均>经典肺炎克雷伯菌(cKP)。耐药基因kpc的检出率为28.57%,cKP菌株的携带率(48.00%)大于hvKP菌株(12.90%),差异有统计学意义(P=0.004),OXA-48和NDM-1未检出。K1、K2、K5、K20、K54、K57荚膜血清型检出率分别为16.07%、10.71%、3.57%、8.93%、9.68%和3.23%。毒力基因magA、rmpA在hvKP(29.03%,80.65%)中检出率均高于cKP菌株(4.00%,24.00%),差异均有统计学意义(P值均<0.05)。菌株PFGE带型相似度为5.91%～100.00%。结论淮安市临床分离肺炎克雷伯菌多为高毒力菌株,且耐药水平较高,PFGE带型多样性较高,应加强监测及临床抗生素使用指导。

Objective To investigate the drug resistance and molecular characteristics of clinical isolates of Klebsiella pneumoniae in Huai an. Methods Klebsiella pneumoniae strains were collected from pathogen identification network from Jan to Jun in 2018. The phenotype of produce mucus was determined by string test. Drug resistance to 24 antibiotics was detected by MIC method. Capsular serotypes, virulent genes and carbapenem resistant genes were detected by PCR. Molecular subtyping traits of isolated strains were characterized by PFGE. Results A total of the 56 Klebsiella pneumonia strains isolated from clinics were collected, the prevalence of high virulence Klebsiella pneumonia (hvKP) was 55.36%, the classic klebsiella pneumoniae (cKP) accounted for 44.64%. The isolated strains were mainly from abscess (26.79%) and sputum (41.70%) samples. The overall drug resistance of isolated strains were 66.07%, the multi-drug resistant strains accounted for 58.93%, ESBLs isolates accounted for 17.86%, carbapenems (imipenem and meropenem) resistant strains accounted for 35.71%;3 polymyxin resistant strains were identified. Except of chloramphenicol and jimmy floxacin chloramphenicol ,the MIC 50 values to tested antibiotics of hvKP were higher than those of cKP. The detection rate of kpc gene was 28.57%;the prevalence of kpc gene in cKP strains (48.00%) was higher than that of hvKP strains (12.90%),the difference was statistically significant ( P =0.004). The OXA -48 and NDM -1 genes were not detected. The incidences of capsular serotye K1, K2, K5, K20, K54 and K57 were 16.07%, 10.71%, 3.57%, 8.93%, 9.68% and 3.23%, respectively. The detection rates of magA and rmpA of hvKP (29.03%,80.65%) were both higher than those of cKP (4.00%,24.00%), the differences were statistically significant(all P <0.05). The similarity of PFGE bands were 5.91%-100.00%. Conclusion The Klebsiella pneumoniae isolates from clinical in this region were mostly high virulent strains with high drug resistance and high diversity of PFGE band patterns. It was necessary to strengthen monitoring , clinical guidance and control of antibiotic usage.