159例烧伤重症监护病房导管相关性血流感染患者病原菌分布及耐药性分析

Analysis of distribution and drug resistance of pathogens isolated from 159 patients with catheter-related bloodstream infection in burn intensive care unit

目的分析烧伤重症监护病房(ICU)导管相关性血流感染(CRBSI)患者病原菌分布与耐药情况。方法2011年1月—2018年12月,陆军军医大学(第三军医大学)第一附属医院(下称笔者单位)烧伤ICU收治患者中有2264例行中心静脉导管置管,其中159例发生CRBSI[男131例、女28例,年龄43(1,79)岁],收集CRBSI患者从外周静脉血及中心静脉导管血/中心静脉置管前段标本初次分离的病原菌进行以下回顾性分析。采用API微生物鉴定试剂盒和全自动微生物鉴定仪进行病原菌鉴定,采用微量肉汤稀释法或K-B纸片扩散法检测病原菌对氟康唑、伊曲康唑等5种抗真菌药物和替加环素、亚胺培南等37种抗细菌药物的耐药情况,采用改良Hodge试验进一步确认亚胺培南、美罗培南耐药肺炎克雷伯菌,采用D试验检测金黄色葡萄球菌对红霉素诱导克林霉素耐药情况。采用WHONET 5.6软件统计分析各年度CRBSI发生率,CRBSI患者病死率,CRBSI例次发生率及感染部位分布与置管持续时间,革兰阴性菌、革兰阳性菌、真菌及耐甲氧西林金黄色葡萄球菌(MRSA)、甲氧西林敏感金黄色葡萄球菌(MSSA)检出情况,常见革兰阴性菌、革兰阳性菌及真菌对临床常用抗菌药物的耐药情况。结果(1)8年间,CRBSI发生率为7.0%(159/2264),其中2014、2017年CRBSI发生率略高,分别为13.6%(30/221)、11.1%(24/217)。CRBSI患者病死率为7.5%(12/159)。(2)CRBSI例次发生率为14.9%(338/2264);感染部位以股静脉为主,共271例次(80.2%),该部位置管持续时间为9(2,25)d。(3)8年间,共检出病原菌543株,其中革兰阴性菌353株,占65.0%;革兰阳性菌140株,占25.8%;真菌50株,占9.2%。检出率居前3位的病原菌从高到低依次为鲍氏不动杆菌、金黄色葡萄球菌和铜绿假单胞菌,分别占23.2%(126/543)、17.1%(93/543)和15.7%(85/543);真菌以近平滑念珠菌为主。金黄色葡萄球菌中,MRSA占98.9%(92/93)、MSSA占1.1%(1/93)。(4)鲍氏不动杆菌除对多黏菌素B、米诺环素和替加环素的耐药率较低外,对其余抗菌药物的耐药率均较高,为80.1%~100.0%。铜绿假单胞菌对多黏菌素B不耐药,对奈替米星、哌拉西林的耐药率分别为88.7%和92.6%,对其余抗菌药物的耐药率为34.5%~62.7%。肺炎克雷伯菌对替加环素不耐药,对亚胺培南、美罗培南的耐药率均为28.9%(亚胺培南及美罗培南耐药株均经改良Hodge试验进一步确认,9株阳性),对其余抗菌药物的耐药率为40.9%~95.2%。MRSA对大部分抗菌药物的耐药率高于MSSA。MRSA对利奈唑胺、万古霉素、替考拉宁、复方磺胺甲唑、替加环素不耐药,对克林霉素和红霉素的耐药率分别为7.9%和62.0%,对其余抗菌药物的耐药率均高于91.5%。MSSA除对青霉素G、四环素完全耐药外,对其余抗菌药物均不耐药。33株金黄色葡萄球菌出现对红霉素诱导克林霉素耐药现象。真菌对两性霉素B不耐药,对伏立康唑、伊曲康唑、酮康唑、氟康唑的耐药率为4.2%~6.2%。结论笔者单位烧伤ICU收治患者CRBSI发生率及其所致病死率均较高,感染部位以股静脉为主;CRBSI患者病原菌种类繁多,以革兰阴性菌为主,检出率居前3位的为鲍氏不动杆菌、金黄色葡萄球菌和铜绿假单胞菌,且存在较严重的耐药现象。

Objective To analyze the distribution and drug resistance of pathogens isolated from patients with catheter-related bloodstream infection(CRBSI)in burn intensive care unit(BICU).Methods From January 2011 to December 2018,among 2264 patients who were peripherally inserted central venous catheter at the BICU of the First Affiliated Hospital of Army Medical University(the third Military Medical University),hereinafter referred to as the author′s unit,159 patients were diagnosed CRBSI,including 131 males and 28 females,aged 43(1,79)years.The pathogens primarily isolated from peripheral venous blood and central venous catheter blood/anterior central venous catheter specimen of patients with CRBSI were retrospectively analyzed.API bacteria identification kits and automatic microorganism identification instrument were used to identify pathogens.Broth micro-dilution method or Kirby-Bauer paper disk diffusion method was used to detect the drug resistance of the pathogens to 5 antifungal drugs including fluconazole and itraconazole,etc.,and 37 antibacterial drugs including tigecycline and imipenem,etc.Modified Hodge test was used to further identify imipenem-and meropenem-resistant Klebsiella pneumonia.D test was used to detect erythromycin-induced clindamycin resistant Staphylococcus aureus.The WHONET 5.6 software was applied to analyze the annual incidence of CRBSI,mortality of patients with CRBSI,incidence of CRBSI cases,distribution of infection site,and duration of catheterization,detection of Gram-negative and Gram-positive bacteria,fungi,methicillin-resistant Staphylococcus aureus(MRSA),and methicillin-sensitive Staphylococcus aureus(MSSA),and drug resistance of fungi and major Gram-negative and Gram-positive bacteria to the commonly used antibiotics in clinic.Results(1)The incidence of CRBSI was 7.0%(159/2264)during the eight years,which was slightly higher in 2014 and 2017 with 13.6%(30/221)and 11.1%(24/217)respectively.The mortality rate of patients with CRBSI was 7.5%(12/159).(2)The incidence of CRBSI cases was 14.9%(338/2264);the main infection site was femoral vein,totally 271 cases(80.2%),and the duration of catheterization of this site was 9(2,25)d.(3)During the eight years,totally 543 strains of pathogens were isolated,including 353(65.0%)strains of Gram-negative bacteria,140(25.8%)strains of Gram-positive bacteria,and 50(9.2%)strains of fungi.The top three isolated pathogens with isolation rate from high to low were Acinetobacter baumannii,Staphylococcus aureus,and Pseudomonas aeruginosa,accounting for 23.2%(126/543),17.1%(93/543),and 15.7%(85/543),respectively.Fungi were mainly Candida parapsilosis.Among the Staphylococcus aureus,the detection rate of MRSA was 98.9%(92/93),and that of MSSA was 1.1%(1/93).(4)Except for the low drug resistance rates to polymyxin B,minocycline,and tigecycline,the drug resistance rates of Acinetobacter baumannii to the other antibiotics were considerably high(80.1%-100.0%).Pseudomonas aeruginosa was not resistant to polymyxin B but highly resistant to netilmicin(88.7%)and piperacillin(92.6%),with resistance rates to the other antibiotics from 34.5%to 62.7%.Klebsiella pneumoniae was not resistant to tigecycline and lowly resistant to imipenem and meropenem(28.9%,9 imipenem-and meropenem-resistant strains were further confirmed by modified Hodge test),with resistance rates to the other antibiotics from 40.9%to 95.2%.The resistance rates of MRSA to most antibiotics were higher than those of MSSA.MRSA was not resistant to linezolid,vancomycin,teicoplanin,sulfamethoxazole,or tigecycline.The resistance rates of MRSA to clindamycin and erythromycin were 7.9% and 62.0%,respectively,and those to the other antibiotics were higher than 91.5%.Except for the complete resistance to penicillin G and tetracycline,MSSA was not resistant to the other antibiotics.Thirty-three strains of Staphylococcus aureus showed resistance to erythromycin-induced clindamycin.Fungi was not resistant to amphotericin B,with drug resistance rates to voriconazole,itraconazole,ketoconazole,and fluconazole from 4.2%to 6.2%.Conclusions The incidence of CRBSI and mortality of patients with CRBSI are high in BICU of the author′s unit,and the main infection site is femoral vein.There are various types of pathogens in patients with CRBSI,and most of them are Gram-negative.The top three isolated pathogens are Acinetobacter baumannii,Staphylococcus aureus,and Pseudomonas aeruginosa,accompanying with grim drug resistance phenomenon.