北京协和医院内科住院患者细菌耐药性监测

Surveillance of Antimicrobial Resistance among Clinical Isolates from Medical Wards in Peking Union Medical College Hospital

目的 了解北京协和医院内科住院患者临床分离细菌的分布及对抗菌药物的耐药性.方法 收集2011年1月1日至2012年12月31日北京协和医院内科临床分离的2767株非重复细菌,采用纸片扩散法或自动化仪器法进行药敏试验,按美国临床实验室标准化研究所2012年版标准判读药敏结果,采用WHONET 5.6软件进行数据分析.结果 2767株非重复细菌中10种最常见的细菌依次为铜绿假单胞菌（11.5％）、大肠埃希菌（11.2％）、金黄色葡萄球菌（10.1％）、肺炎克雷伯菌（9.7％）、鲍曼不动杆菌（9.4％）、凝固酶阴性葡萄球菌（5.0％）、阴沟肠杆菌（4.1％）、粪肠球菌（3.8％）、嗜麦芽窄食单胞菌（3.6％）和屎肠球菌（3.4％）,其中革兰阴性菌占65.3％（1807株）,革兰阳性菌占34.7％（960株）.耐甲氧西林金黄色葡萄球菌（methicillin-resistant Staphylococcus aureus,MRSA）和耐甲氧西林凝固酶阴性葡萄球菌（methicillin-resistant coagulase negative Staphylococcus,MRCNS）的检出率分别为33.8％ （94/278）和75.8％（222/293）.MRS葡萄球菌（MRSA和MRCNS）对β内酰胺类和其他抗菌药物的耐药率明显高于MSS葡萄球菌[甲氧西林敏感金黄色葡萄球菌（methicillin-susceptible Staphylococcus aureus,MSSA）和甲氧西林敏感凝固酶阴性葡萄球菌（methicillin-susceptive coagulase-negative Staphylococcus,MSCNS）].MRSA中87.2％菌株对磺胺甲噁唑-甲氧苄啶敏感,MRCNS中84.2％菌株对利福平敏感.未发现对万古霉素、替考拉宁和利奈唑胺耐药的葡萄球菌.粪肠球菌对大多数抗菌药物的耐药率明显低于屎肠球菌,后者对氯霉素的耐药率仅为4.7％.分别发现2株和8株万古霉素耐药的粪肠球菌和屎肠球菌,根据表型推测为VanA和VanB型耐药；未发现对利奈唑胺耐药的肠球菌.产超广谱β-内酰胺酶（extended spectrum β-lactamases,ESBLs）的大肠埃希菌、克雷伯菌属细菌（肺炎克雷伯菌和产酸克雷伯菌）和奇异变形杆菌的检出率分别为66.5％、32.6％和30.5％,产ESBLs菌株的耐药率明显高于非产ESBLs菌株.肠杆菌科细菌对碳青霉烯类抗菌药物仍高度敏感,总耐药率0.9％ ～2.9％.泛耐药肺炎克雷伯菌的检出率为0.4％ （1/267）.铜绿假单胞菌对亚胺培南和美罗培南的耐药率分别为23.4％和t7,4％,对阿米卡星的耐药率最低（6.6％）；鲍曼不动杆菌对上述两种抗菌药物的耐药率分别为56.8％和57.5％,对头孢哌酮-舒巴坦和米诺环素的耐药率最低（42.1％和24.0％）.泛耐药鲍曼不动杆菌和铜绿假单胞菌的检出率分别为35.9％和1.6％.流感嗜血杆菌β-内酰胺酶的检出率为19.4％.肺炎链球菌对红霉素和克林霉素的耐药率＞94％.结论 定期进行耐药性监测有助于了解细菌耐药性变迁,可为临床经验用药提供依据.

Objective To investigate the distribution and antimicrobial resistance of clinical bacterial isolates from medical wards in Peking Union Medical College Hospital （PUMCH） between January 1, 2011 and December 31, 2012. Methods A total of 2767 non-duplicate clinical isolates were collected. Disc diffusion test （Kirby-Bauer method） and automated systems were employed to study the antimicrobial resistance. The data were analyzed by WHONET 5. 6 software according to Clinical and Laboratory Standards Institute （CLSI） 2012 break- points. Results Of the 2767 clinical isolates, gram-negative organisms and gram-positive cocci accounted for 65.3% （n = 1807） and 34. 7% （n =960）, respectively. The 10 most common organisms isolated were Pseudo- monas aeruginosa （ 11.5% ）, Escherichia coli （ 11.2% ）, Staphylococcus aureus （ 10. 1% ）, Klebsiella pneumoniae （9. 7% ）, Acinetobaeter baumannii （ 9. 4% ）, coagulase-negative staphylococci （ 5. 0% ）, Enterobacter cloacae （4. 1% ）, Enterococcus faecalis （3.8%）, Xanthomonus maltophilia （3.6%）, and Enterococcttsfaecalis （3.4%）. Methicillin-resistant Staphylococcus aureus （MRSA） and methicillin-resistant coagulase negative Staphylococcus （MRCNS） accounted for 33.8% and 75.8%, respectively. The resistance rates of methicillin-resistance strains to 13-1actams and other antimicrobial agents were much higher than those of methicillin-susceptive strains including methicillin-susceptible Staphylococcus aureus （ MSSA ） and methiciUin-susceptive coagulase-negative Staphylococcus （MSCNS）. In addition, 87. 2% of MRSA strains were still susceptible to trimethoprim-sulfamethoxazole, while 84. 2% of MRCNS strains were susceptible to rifampin. No staphylococcal strains were resistant to vancomycin, teicoplanin, or linezolid. The resistance rates of E. faecalis strains to most of the drugs tested were much lower than those of E. faecium. However, the resistance rate of the E. faecium to chloramphenicd was only 4. 7%. Several strains of both E. faecium and E. faecalis were found resistant to vancomycin. Most of the vancomycin-resistant strains were van-A and van-B types based on their phenotypes. No linezolid-resistant strains were found. Extended spectrum 13-1actamases （ESBLs）-producing strains accounted for 66. 5%, 32. 6%, and 30. 5% in E. coli, Kleb- siella spp （K. pneumoniae and K. oxytoca）, and P. mirabilis, respectively. The resistant rates of ESBLs-produ- cing strains were all higher than the corresponding non-ESBLs-producing strains. The Enterbacteriaceae strains were still highly susceptible to carbapenems, with an overall resistance rate of only 0. 9% -2. 9%. Only one pan-resist- ant strain of K. pneumoniae （0. 4%, 1/267） was identified. The resistance rates of P. aeruginosa to imipenem and meropenem were 23.4% and 17.4%, respectively. However, the P. aeruginosa isolates showed the lowest re- sistant rate （6. 6% ） to amikacin. Also, 56. 8% and 57.5% ofA. baumannii were resistant to imipenem and mero- penem. A. baumannii isolates showed the lowest resistant rates 42. 1% and 24. 0%, respectively, to cefoperazone- sulbactam and minocycline. The prevalences of pan-resistant strains of A. baumannii and P. aeruginosa were 35.9% and 1.6%, respectively. The detection rate of 15-1actamase in H. influenzae was 19. 4%. More than 94% of S. pneumoniae strains were resistant to erythromycin and clindamycin. Conclusion Regular monitoring of the bacterial resistance to antibiotics is useful to guide the rational use of antimicrobial agents.