血流感染中高毒力肺炎克雷伯菌的荚膜多糖血清型特点、多位点序列分型研究

Serotype characteristics of the capsular polysaccharide and multi-site sequence typing of hypervirulent Klebsiella pneumoniae in bloodstream infection

目的分析血流感染中高毒力肺炎克雷伯菌(hvKP)的荚膜多糖血清分型特点、多位点序列分型。方法选取2020年10月—2021年12月河南省人民医院临床分离自血培养的165株肺炎克雷伯菌作为本次实验对象。应用基质辅助激光解析电离飞行时间质谱技术鉴定分离出的菌株,其中高毒力肺炎克雷伯菌(hvKP)55株,普通的肺炎克雷伯菌(KP)110株,采用微生物鉴定药敏分析仪进行药敏试验,分析其耐药性,通过聚合酶链式反应技术检测荚膜多糖血清分型和多位点序列分型。结果hvKP对常见抗菌药物的耐药率均低于KP,且对头孢他啶、头孢噻肟、头孢吡肟、左氧氟沙星、阿米卡星、亚胺培南、美罗培南的耐药率较低(P<0.05);两组在K1、K2、K5、K54、K57荚膜多糖血清分型的分布比较方面差异较大(P<0.05),且与KP相比较,hvKP荚膜多糖血清分型K1、K2的检出率较高,K5、K54、K57的检出率较低(P<0.05);ST23、ST86、ST65是hvKP主要的多位点序列分型,依次占比32.73%、20.00%、16.36%。结论引起的血流感染的hvKP对大部分常用抗菌药物的耐药性较低,临床可根据患者实际情况和药敏结果,合理使用抗菌药物。同时hvKP血清荚膜分型以K1、K2为主,多位点序列分型则以ST23、ST86、ST65为主。

Objective To analyze the serotype characteristics of the capsular polysaccharide and multi-site sequence typing of hypervirulent Klebsiella pneumoniae in bloodstream infection.Methods Totally 165 Klebsiella pneumoniae clinically isolated from blood culture in our hospital from October 2020 to December 2021 were selected as the subjects of this experiment.Stroma-assisted laser analytical ionization time-of-flight mass spectrometry was used to identify the isolated strains,including 55 hypervirulent Klebsiella pneumoniae(hvKP)strains and 110 common Klebsiella pneumon⁃iae(KP)strains.Drug sensitivity tests were carried out by microbial identification drug sensitivity analyzer to analyze their drug resistance.Serum capsule typing and multisite sequence typing were detected by polymerase chain reaction.Results The resistance rate of hvKP to common antibiotics was lower than that of KP,and the resistance rate of hvKP to ceftazidime,cefotaxime,cefepime,levofloxacin,amikacin,imipenem and meropenem was lower(P<0.05).There were significant differences in the distribution and comparison of serum capsular types K1,K2,K5,K54 and K57 be⁃tween the two groups(P<0.05),and compared with KP,the detection rate of serum capsular types K1 and K2 was higher in hvKP,while that of K5,K54 and K57 was lower(P<0.05).ST23,ST86 and ST65 were the main multilocus sequences typing of hvKP,accounting for 32.73%,20.00%and 16.36%.Conclusion The drug resistance of hvKP caused by bloodstream infection is low to most common antibiotics,antibiotics can be used rationally according to the actual situation of patients and the results of drug sensitivity.At the same time,K1 and K2 were the main types in ser⁃um capsula of hvKP,while ST23,ST86 and ST65 were the main types in multilocus sequences.