肺炎克雷伯菌对头孢吡肟和厄他培南异质性耐药的临床特征与危险因素分析

Clinical features and risk factors of infections caused by Klebsiella pneumoniae with heteroresistance to cefepime and ertapenem

目的研究对头孢吡肟异质性耐药肺炎克雷伯菌(Cefepime-heteroresistant Klebsiella pneumoniae,FEP-HR-KP)和对厄他培南异质性耐药肺炎克雷伯菌(Ertapenem-heteroresistant Klebsiella pneumoniae,ETP-HR-KP)感染的临床特征和危险因素。方法收集2014-2015年从本院住院患者无菌体液标本中分离的108株肺炎克雷伯菌进行回顾性病例对照研究。采用纸片扩散法(Kirby-Bauer disk diffusion test,K-B test)和E-test法进行异质性耐药初筛,菌谱分析(population analysis profile,PAP)实验确认。采用χ2检验和Logistic回归对患者病例资料进行危险因素分析。结果共分离了108株肺炎克雷伯菌,其中41 (40. 0%)株对头孢吡肟异质性耐药,63 (58. 3%)株对厄他培南异质性耐药,38(35. 2%)株同时对头孢吡肟和厄他培南异质性耐药,且年异质性耐药率呈现增长趋势,FEP-HR-KP从2014年的41. 7%(20/48)增长到2015年的51. 7%(31/60),ETP-HR-KP从2014年的54. 1%(26/48)增长到2015年的61. 7%(37/60)。肺炎克雷伯菌主要分离自血液标本(25/66,37. 9%),且超过一半都来自外科(47/66,71. 2%)。多因素Logistic回归分析结果显示:软组织感染(OR:1. 92,95%CI:0. 91～3. 91,P=0. 049)、机械通气(OR:2. 45,95%CI:1. 31～4. 47,P=0. 013)、头孢菌素类抗生素使用(OR:2. 10,95%CI:1. 18～3. 13,P=0. 020)是FEP-HR-KP相关感染的独立危险因素;头孢类抗生素使用(OR:2. 08,95%CI:0. 96～4. 20,P=0. 033)、碳青霉烯类抗生素使用(OR:2. 52,95%CI:1. 08～3. 86,P=0. 023)、内置引流管(OR:2. 76,95%CI:1. 49～4. 90,P=0. 018)是ETP-HR-KP相关感染的独立危险因素。结论本院肺炎克雷伯菌对头孢吡肟和厄他培南的异质性耐药率较高。减少不必要的侵入性操作和合理使用抗生素有助于减少异质性耐药菌株的产生并提高临床治疗效果。

Objective To investigate the clinical features and risk factors of infections caused by cefepime-and ertapenem-heteroresistant Klebsiella pneumoniae( FEP-HR-KP and ETP-HR-KP,respectively).Methods We conducted a retrospective case-control study of 108 Klebsiella pneumoniae strains isolated from the body fluids of the inpatients in our hospital from January,2014 to December,2015. The heteroresistance of the isolated strains was detected using Kirby-Bauer disk diffusion test( K-B test) and E-test,and the results were further confirmed by population analysis profile( PAP) method. The risk factors for infections by FEPHR-KP and ETP-HR-KP were analyzed using Chi-square test and logistic regression analysis. Results Of the total of 108 non-duplicate Klebsiella pneumoniae strains isolated,41( 40. 0%) were heteroresistant to cefepime,63( 58. 3%) were heteroresistant to ertapenem,and 38( 35. 2%) showed heteroresistance to both.The annual detection rate of FEP-HR-KP increased from 41. 7%( 20/48) in 2014 to 51. 7%( 31/60) in2015,and that of ETP-HR-KP increased from 54. 1%( 26/48) in 2014 to 61. 7%( 37/60) in 2015. The strains were isolated mainly from blood specimens( 25/66,37. 9%),and more than half( 47/66,71. 2%)of the strains were isolated from the department of surgery. Multivariate logistic regression analysis revealed that soft tissue infection( OR = 1. 92,95% CI: 0. 91 ~ 3. 91,P = 0. 049),mechanical ventilation( OR =2. 45,95% CI: 1. 31 ~ 4. 47,P = 0. 013),and use of cephalosporins( OR = 2. 10,95% CI: 1. 18 ~ 3. 13,P = 0. 020) were independent risk factors for infections by FEP-HR-KP;use of cephalosporins( OR = 2. 08,95% CI: 0. 96 ~ 4. 20,P = 0. 033),use of carbapenems( OR = 2. 52,95% CI: 1. 08 ~ 3. 86,P = 0. 023)and drainage tube placement( OR = 2. 76,95% CI: 1. 49 ~ 4. 90,P = 0. 018) were independent risk factors for ETP-HR-KP infections. Conclusion The Klebsiella pneumoniae strains isolated in our hospital show high rates of heteroresistance to cefepime and ertapenem. Avoiding unnecessary invasive operation and optimizing the use of antibiotics can help to reduce the generation of heteroresistant strains and improve the treatment efficacy for FEP-HR-KP and ETP-HR-KP infections.