摘要目的:通过研究血液感染的病原菌分布及对其耐药性监测，准确掌握我国细菌耐药状况。方法:收集全国血流感染细菌耐药监测联盟(BRICS)成员单位2016年1月至2017年12月所有按操作规程分离自血培养的感染病原菌，按美国临床和实验室标准化研究所(CLSI)推荐的琼脂稀释法或肉汤稀释法进行抗菌药物药敏性测定。采用WHONET 5.6进行统计分析。结果:2016年1月至2017年12月共收集33家成员单位8 154株病原菌，其中革兰阳性菌为2 325株(28.5%)，革兰阴性菌5 829株(71.5%)。最常见的前10位病原菌为大肠埃希菌2 831株(34.7%)、肺炎克雷伯菌1 289株(15.8%)、金黄色葡萄球菌922株(11.3%)、凝固酶阴性葡萄球菌605株(7.4%)、鲍曼不动杆菌372株(4.6%)、铜绿假单胞菌315株(3.9%)、屎肠球菌312株(3.8%)、链球菌属237株(2.9%)、阴沟肠杆菌220株(2.7%)和粪肠球菌205株(2.5%)。耐甲氧西林金黄色葡萄球菌(MRSA)和耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)检出率分别为34.2%(315/922)和77.7%(470/605)，未检测到对万古霉素耐药的葡萄球菌。屎肠球菌对万古霉素的耐药率为0.6%(2/312)，未检测到耐万古霉素的粪肠球菌。产超广谱β-内酰胺酶(ESBLs)大肠埃希菌、肺炎克雷伯菌、变形杆菌属分别为55.7%(1 576/2 831)、29.9%(386/1 289)、38.5%(15/39)；耐碳青霉烯类大肠埃希菌、肺炎克雷伯菌分别为1.2%(33/2 831)、17.5%(226/1 289)。鲍曼不动杆菌对多黏菌素B和替加环素的耐药率分别为14.8%(55/372)和5.9%(22/372)；铜绿假单胞菌对多黏菌素B和碳青霉烯类的耐药率分别为1.3%(4/315)和18.7%(59/315)。结论:我国血流感染病原菌以革兰阴性菌为主，大肠埃希菌为最常见的病原菌；MRSA的检出率较国内同期其他监测低；耐碳青霉烯大肠埃希菌处于较低水平，耐碳青霉烯肺炎克雷伯菌呈上升趋势。

abstractsObjective:To investigate the distribution and antimicrobial resistance profile of clinical bacteria isolated from blood culture in China.Methods:The clinical bacterial strains isolated from blood culture from member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS) were collected during January 2016 to December 2017. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by US Clinical and Laboratory Standards Institute (CLSI) 2019. WHONET 5.6 was used to analyze data.Results:During the study period, 8 154 bacterial strains were collected from 33 hospitals, of which 2 325 (28.5%) were Gram-positive bacteria and 5 829 (71.5%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (34.7%), Klebsiella pneumoniae (15.8%), Staphylococcus aureus (11.3%), coagulase-negative Staphylococci (7.4%), Acinetobacter baumannii (4.6%), Pseudomonas aeruginosa (3.9%), Enterococcus faecium (3.8%), Streptococci (2.9%), Enterobacter cloacae (2.7%) and Enterococcus faecalis (2.5%). Methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus (MRCNS) accounted for 34.2%(315/922) and 77.7%(470/605), respectively. No vancomycin-resistant Staphylococcus was detected. The resistance rate of Enterococcus faecium to vancomycin was 0.6%(2/312), and no vancomycin-resistant Enterococcus faecium was detected. The ESBLs-producing rates in Escherichia coli, Klebsiella pneumoniae and Proteus were 55.7%(1 576/2 831), 29.9%(386/1 289) and 38.5%(15/39), respectively. The incidences of carbapenem-resistance in Escherichia coli, Klebsiella pneumoniae were 1.2%(33/2 831), 17.5%(226/1 289), respectively. The resistance rates of Acinetobacter baumannii to polymyxin and tigecycline were 14.8%(55/372) and 5.9%(22/372) respectively, and those of Pseudomonas aeruginosa to polymyxin and carbapenem were 1.3%(4/315) and 18.7%(59/315), respectively. Conclusion:The surveillance results from 2016 to 2017 showed that the main pathogens of blood stream infection in China were gram-negative bacteria, while Escherichia coli was the most common pathogen; the MRSA incidence was lower than other surveillance data in the same period in China; carbapenem-resistant Escherichia coli was at a low level during this surveillance, while carbapenem-resistant Klebsiella pneumoniae is on the rise.