某三甲教学医院2016?2020年血标本病原菌耐药性变迁

  目的  了解本院2016?2020年间血液标本病原菌分布及耐药变迁，为临床血流感染诊治提供依据。  方法  使用Bruker MALDI-TOF质谱仪进行细菌鉴定，VITEK 2 Compact细菌鉴定药敏仪进行抗菌药物敏感性试验，部分采用纸片扩散法，数据采用WHONET 5.6软件进行统计分析。  结果  2016?2020年本院临床血液标本来源分离菌株共8931株，其中革兰阳性菌4502株（50.4%），革兰阴性菌4429株（49.6%）。肠杆菌目细菌大肠埃希菌（1773株，19.9%）居首位，其次是肺炎克雷伯菌（1067株，11.9%），非发酵菌以鲍曼不动杆菌（293株，3.3%）和铜绿假单胞菌（238株，2.7%）为主，葡萄球菌菌种前三位分布为表皮葡萄球菌（970株，10.9%）、人葡萄球菌（713株，8.0%）和金黄色葡萄球菌（541株，6.1%）。大肠埃希菌对头孢哌酮/舒巴坦、阿米卡星、多粘菌素B、替加环素及碳青霉烯类药敏的体外活性较高，敏感率均在90%以上，对亚胺培南的耐药率有缓慢上升的趋势，美罗培南的耐药率为2.2%～3.4%。肺炎克雷伯菌对常见抗生素体外耐药率高于大肠埃希菌，仅替加环素和多粘菌素B的敏感率大于90%，亚胺培南和美罗培南的耐药率逐年升高。铜绿假单胞菌自2017年起对亚胺培南耐药率有下降（25.6%～18.6%），鲍曼不动杆菌对亚胺培南和美罗培南的耐药率为73.7%～91.3%和73.0%～91.3%。未发现对万古霉素、利奈唑胺耐药的葡萄球菌属细菌。肠球菌对万古霉素和利奈唑胺的耐药性均较低。  结论  本院临床血液标本常见病原菌菌种分布无明显改变，但多重耐药菌的耐药形势日趋严峻，特别是耐碳青霉烯类肺炎克雷伯菌。

Changes and Trends of Drug Resistance of Pathogenic Bacteria in Blood Samples of a Tertiary-Level Teaching Hospital from 2016 to 2020

  Objective  To investigate the distribution of pathogenic bacteria in blood samples and changes in their drug resistance in our hospital from 2016 to 2020, and to provide evidence for the diagnosis and treatment of clinical bloodstream infections.  Methods  Bruker Corporation’s matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used for bacterial identification, VITEK 2 Compact was used for antimicrobial susceptibility test, some of which was done with the Kirby-Bauer method, and the data was statistically analyzed with WHONET 5.6 software.  Results  A total of 8931 bacterial strains, including 4502 (50.4%) Gram-positive bacteria and 4429 (49.6%) Gram-negative bacteria, were isolated from the blood samples between 2016 and 2020. Among the isolated bacteria of the order Enterobacterales, Escherichia coli (1773, 19.9%) ranked first, followed by Klebsiella pneumoniae (1067, 11.9%). The non-fermenting bacteria identified were predominantly Acinetobacter baumannii (293, 3.3%) and Pseudomonas aeruginosa (238, 2.7%). The top three Staphylococcus species were Staphylococcus epidermidis (970 strains, 10.9%), Staphylococcus hominis (713, 8.0%) and Staphylococcus aureus (541, 6.1%). Escherichia coli showed high in vitro susceptibility to cefoperazone/sulbactam, amikacin, polymyxin B, tigecycline, and carbapenems, and the sensitivity rate was consistently over 90%. The resistance rate to imipenem showed a trend of slow growth, and the resistance rate of meropenem was 2.2% to 3.4%. Klebsiella pneumoniae showed higher in vitro resistance rate to common antibiotics than that of Escherichia coli, with only the sensitivity rates to tigecycline and polymyxin B being higher than 90%, and the resistance rate to imipenem and meropenem increasing year by year. The resistance rate of Pseudomonas aeruginosa to imipenem decreased since 2017 (from 25.6% to18.6%), and the resistance rate of Acinetobacter baumannii to imipenem and meropenem were 73.7%-91.3% and 73.0%-91.3%. Staphylococcus resistant to vancomycin or linezolid was not found. Enterococci showed rather low resistance to vancomycin and linezolid.  Conclusion   The distribution of common species of pathogenic bacteria in clinical blood samples in our hospital did not show significant changes, but the problem of multi-drug resistant bacteria is becoming increasingly more serious, especially so for carbapenem-resistant Klebsiella pneumoniae.