全国细菌耐药监测网2014-2019年老年患者常见临床分离细菌耐药性监测报告

 目的 了解全国老年患者感染细菌的分布及其对常用抗菌药物的敏感性，为老年患者感染的经验性治疗提供参考。方法 2014-2019年全国细菌耐药监测网医院按照统一的技术方案，采用纸片扩散法、自动化仪器法或E-test法进行细菌药物敏感性试验，应用WHONET 5.6软件分析老年（≥ 65岁）患者病原菌数据。结果 2014-2019年各年度革兰阳性菌和革兰阴性菌占比维持在1：4左右。革兰阳性菌中金黄色葡萄球菌占5.9%~6.3%，屎肠球菌占3.1%~4.0%，粪球菌占2.8%~2.9%。耐甲氧西林金黄色葡萄球菌（MRSA）检出率逐年下降，从48.8%下降至35.2%，凝固酶阴性葡萄球菌中耐甲氧西林凝固酶阴性葡萄球菌（MRCNS）检出率在80.0%左右，未发现耐万古霉素、替考拉宁的菌株。粪肠球菌对万古霉素的耐药率从1.1%下降至0.3%，屎肠球菌从3.7%下降至1.4%。非脑脊液标本分离的肺炎链球菌对头孢噻肟的耐药率逐年下降，从10.0%降至6.1%。革兰阴性菌中居前四位分离菌排序无变化，分别是大肠埃希菌、肺炎克雷伯菌、铜绿假单胞菌、鲍曼不动杆菌。大肠埃希菌对头孢曲松和头孢噻肟的耐药率仍高于54%，对碳青霉烯类的耐药率在1.3%左右。肺炎克雷伯菌对亚胺培南和美罗培南耐药率持续上升，分别从5.6%上升至11.7%、5.2%上升至12.1%。铜绿假单胞菌和鲍曼不动杆菌对碳青霉烯类耐药率分别在20%左右和56%以上。除头孢他啶外，2015年嗜麦芽窄食单胞菌对其他检测抗菌药物耐药率显著下降，此后呈小幅波动，波幅介于0.9%~1.4%。流感嗜血杆菌对氨苄西林耐药率连续上升，2019年已达63.8%。结论 老年患者临床分离细菌以革兰阴性菌为主，临床重要耐药菌MRSA和耐万古霉素肠球菌分离率持续下降，而耐碳青霉烯类肺炎克雷伯菌分离率持续上升，需特别关注。

Antimicrobial resistance of clinically isolated bacteria from elderly patients:surveillance report from China Antimicrobial Resistance Surveillance System in 2014-2019

Objective To analyze the distribution and antimicrobial susceptibility of bacterial strains isolated from elderly patients in China, and provide reference for empirical treatment of infection in elderly patients. Methods In 2014-2019,according to technical program of China Antimicrobial Resistance Surveillance System(CARSS), antimicrobial susceptibility testing was performed by Kirby-Bauer method, automatic instrument method or E-test method, data of pathogenic bacteria from elderly patients (≥ 65 years old) were analyzed by WHONET 5.6 software. Results From 2014 to 2019, the ratio of Gram-positive bacteria to Gram-negative bacteria remained at about 1:4 yearly. Among Gram-positive bacteria, Staphylococcus aureus accounted for 5.9%-6.3%, Enterococcus faecium and Enterococcus faecalis accounted for 3.1%-4.0% and 2.8%-2.9% respectively. Isolation rate of methicillin-resistant Staphylococcus aureus (MRSA) decreased year by year, from 48.8% to 35.2%, isolation rate of methicillin-resistant coagulase negative Staphylococcus (MRCNS) accounted for about 80.0% of coagulase negative Staphy-lococcus, vancomycin- and teicoplanin-resistant strains was not found. Resistance rates of Enterococcus faecalis and Enterococcus faecium to vancomycin decreased from 1.1% to 0.3% and 3.7% to 1.4% respectively. Resistance rate of Streptococcus pneumoniae isolated from non-cerebrospinal fluid specimens to cefotaxime decreased year by year, from 10.0% to 6.1%. The top 4 isolated Gram-negative bacteria were Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii. Resistance rates of Escherichia coli to ceftriaxone and cefotaxime were still higher than 54%, to carbapenems was about 1.3%. Resistance rates of Klebsiella pneumoniae to imipenem and meropenem continued to rise, from 5.6% to 11.7% and 5.2% to 12.1% respectively. Resistance rates of Pseudomonas aeruginosa and Acinetobacter baumannii to carbapenems were about 20% and >56% respectively. Except for ceftazidime, resistance rates of Stenotrophomonas maltophilia to other antimicrobial agents decreased significantly in 2015, and then fluctuated slightly, ranging from 0.9% to 1.4%. Resistance rate of Haemophilus influenzae to ampicillin increased continuously, reaching 63.8% in 2019. Conclusion Gram-negative bacteria are the main pathogens causing infection in the elderly, isolation rates of clinically important antimicrobial-resistant bacteria MRSA and vancomycin-resistant Enterococcus continue to decline, while isolation rate of carbapenem-resistant Klebsiella pneumoniae increased persistently, which needs special attention.