广东地区血液内科血流感染的病原菌流行病学分析

Epidemiological analysis of pathogens causing bloodstream infections in department of hematology in Guangdong Province

目的分析广东省50家医院血液内科血标本来源细菌的构成和耐药性,了解血液内科血流感染(BSI)的流行病学特征。方法基于国家细菌耐药监测网(CARSS)平台,对2019年广东省50家医院血液内科、呼吸内科和ICU由血标本分离的病原菌分布和碳青霉烯类耐药革兰阴性菌(CRO)检出率进行分析,同时对大肠埃希菌、肺炎克雷伯菌和铜绿假单胞菌药敏特征分儿童组(≤14岁)和成人组(>14岁)进行分析。参考CLSI 2019年M100文件标准判断结果。结果共收集广东省50家医疗机构(三级医院48家)血液内科、呼吸内科、重症监护治疗病房(ICU)三个科室各1618、1026、3626株血标本分离菌完整微生物信息资料。其中血液内科革兰阴性杆菌占71.8%,革兰阳性球菌占28.2%。血液内科分离前5位细菌是:大肠埃希菌、肺炎克雷伯菌、铜绿假单胞菌、凝固酶阴性葡萄球菌和草绿色链球菌群。葡萄球菌属中耐甲氧西林金黄色葡萄球菌(MRSA)、耐甲氧西林的凝固酶阴性葡萄球菌(MRSCN)的检出率分别为19.7%和80.6%,未发现对万古霉素、利奈唑胺、替考拉宁耐药的菌株,无利奈唑胺耐药的肠球菌。草绿色链球菌群对青霉素G的耐药率为6.9%,对头孢曲松和头孢噻肟耐药率均超过25.0%。肠杆菌科细菌中大肠埃希菌和肺炎克雷伯菌儿童组耐药率普遍高于成人组。成人组肺炎克雷伯菌对美罗培南耐药率为14.1%,阴沟肠杆菌对碳青霉烯类耐药率超过25.0%,非发酵菌中铜绿假单胞菌对大部分抗菌药物敏感性超过80.0%,但儿童组对美罗培南的耐药率高于成人组(11.8%对6.5%)。鲍曼不动杆菌无对替加环素耐药菌株。科室之间比较,ICU和呼吸内科血标本革兰阳性球菌比例高于血液内科。呼吸内科碳青霉烯类耐药大肠埃希菌(CREC)和碳青霉烯类耐药肺炎克雷伯菌(CRKP)检出率最低,分别为0.3%和3.7%。血液内科碳青霉烯类耐药铜绿假单胞菌(CRPA)和碳青霉烯类耐药鲍曼不动杆菌(CRAB)检出率最低,分别为8.3%和25.8%。ICU整体碳青霉烯类耐药的革兰阴性杆菌检出率都最高。结论血液内科血标本来源细菌构成比与重要细菌耐药性与呼吸内科、ICU存在差异,广东地区血液内科肺炎克雷伯菌、铜绿假单胞菌、阴沟肠杆菌及以草绿色链球菌群为主的链球菌属比例明显高于ICU和呼吸内科。

Objective To evaluate the epidemiology of bacterial bloodstream infections in patients submitted to hematologic wards in southern China.Methods A total of 50 teaching hospitals were involved based on the China Antimicrobial Resistance Surveillance System.The data of clinical isolates from blood samples were collected from January 1,2019,to December 31,2019.Antimicrobial susceptibility testing was conducted by the Kirby-Bauer automated systems,and the results were interpreted using the CLSI criteria.Results The data of 1,618 strains isolated from hematologic wards in 2019 were analyzed,of which gram-negative bacilli and gram-positive cocci accounted for 71.8%and 28.2%,respectively.Of those,the five major species were most often isolated,including Escherichia coli,Klebsiella pneumoniae,Pseudomonas aeruginosa,coagulase-negative staphylococcus,and Streptococcus viridans.The prevalence rates of methicillin-resistant strains in Staphylococcus aureus and coagulase-negative staphylococcus were 19.7%and 80.6%,respectively.No gram-positive cocci were resistant to vancomycin,linezolid,and teicoplanin,and none of the enterococci were resistant to linezolid.The resistance rate of S.viridans to penicillin G was 6.9%,and those to ceftriaxone and cefotaxime were more than 25%.The resistance rate of E.coli and K.pneumoniae in Enterobacteriaceae was higher in children than that in adults.The resistance rate of K.pneumoniae to meropenem was 14.1%.The resistant rate of Enterobacter cloacae to carbapenem was more than 25%.P.aeruginosa was more sensitive to more antibiotics than 80%,but the resistance rate to meropenem in children was higher than that in adults(11.8%vs.6.5%).The proportion of gram-positive cocci in the ICU and respiratory departments was higher than that in the hematology department.The detection rates of carbapenem-resistant E.coli and K.pneumoniae in the respiratory department were the lowest with 0.3%and 3.7%,respectively,while those of CRPA and CRAB in the hematology department were the lowest with 8.3%and 25.8%,respectively.The detection rate of all carbapenem-resistant organisms in the ICU was the highest among the three departments.Conclusion The etiology and drug resistance of bacteria from blood samples in the hematology department are different from those in the ICU and respiratory departments.The proportions of K.pneumoniae,P.aeruginosa,E.cloacae,and S.viridans dominating in the department of Hematology were significantly higher than those in the ICU and respiratory departments in Guangdong region.