2012年临床分离菌分布及耐药性分析

目的了解南昌大学第二附属医院临床分离菌的分布及耐药特性。方法采用纸片扩散法进行抗菌药物药敏试验，E试验检测葡萄球菌属对万古霉素及肺炎链球菌对青霉素的MIC。参照CLSI2012年版标准判读药敏结果，用WHONET5．5软件进行数据分析。结果2012年共收集到非重复临床分离菌4454株，其中革兰阴性菌3181株（71．4％），革兰阳性菌1273株（28．6％）。呼吸道分泌物标本占28．5％，其次为血液（26．7％）和脓液（包括伤口分泌物，20．3％）。居前5位的病原菌依次为大肠埃希菌（16．1％）、鲍曼不动杆菌（12．4%）、铜绿假单胞菌（11．8％）、肺炎克雷伯菌（10．3％）和金葡菌（8．8％）。葡萄球菌属中耐甲氧西林金葡菌（MRSA）和耐甲氧西林凝固酶阴性葡萄球菌（MRCNS）分别占29．2％和79．0％，未发现对万古霉素、替考拉宁和利奈唑胺耐药株。肺炎链球菌中青霉素耐药株占14．2％，G溶血链球菌对红霉素和克林霉素耐药率较高。屎肠球菌对多数抗菌药物的耐药率高于粪肠球菌，检出2株屎肠球菌和4株粪肠球菌对万古霉素耐药。大肠埃希菌、克雷伯菌属（肺炎克雷伯菌、产酸克雷伯菌）和奇异变形杆菌中ESBLs的检出率分别为68．0％、40．4％和34．0％，ESBLs阳性菌株对大多数抗菌药物的耐药率高于ESBLs阴性的菌株。肠杆菌科细菌对亚胺培南和美罗培南的耐药率均低于10．0％。铜绿假单胞菌对亚胺培南的耐药率为20．2％。鲍曼不动杆菌除对头孢哌酮-舒巴坦外，对其他常用抗菌药物的耐药率均大于60．0％。结论该院临床分离菌耐药现象严重，尤其是鲍曼不动杆菌对碳青霉烯类抗生素耐药率增高较快，应引起重视。

Bacterial distribution and antibiotic resistance analysis during 2012

Objective To investigate the distribution and antimicrobial resistance of clinical bacterial isolates in 2012. Methods Strains were isolated and identified using conventional methods. Antimicrobial susceptibility testing was carried out using Kir- by-Bauer method. The minimum inhibitory concentrations （MICs） of vancomycin for Staphylococcus spp. and penicillin for S. pneumoniae were determined by E-test. Results were interpreted according to the breakpoints of CLSI 2012. All data were ana-lyzed by WHONET 5.5 software. Results A total of 4 454 nonduplicate clinical isolates were collected during 2012, including gram negative bacteria （3 181, 71.4%） and gram positive bacteria （1 273, 28.6%）. The main source of these pathogens was respiratory specimens （28.5 % ）, followed by blood （26.7 % ） and pus （including wound secretion, 20.3 % ）. The top five path-ogenic bacteria were E. coli, A. baumannii, P. aeruginosa, K. pneumoniae and S. aureus, accounting for 16.1 %%0, 12.4%, 11.8%, 10.3% and 8.8%, respectively. The prevalence of MRSA in S. aureus and MRCNS in coagulase-negative Staphylo-coccus was 29.2% and 79.0%, respectively. No staphylococcal strain was found resistant to vancomycin, teicoplanin or linezol-id. The prevalence of penicillin-resistant S. pneumoniae was 14.2% in non-cerebrospinal fluid. The beta-hemolytic Streptococ- cus strains showed higher resistance rates to eythromycin and clindamycin. E. faecium strains showed much higher resistance rates to most antibiotics tested than E. faecalis. Vancomycin resistance was found in 2 E. faecium strains and 4 E. faecalis strains. The prevalence of ESBLs was 68. 0% in E. coli, 40.4% in Klebsiella spp. （K. pneumoniae and K. oxytoca） and 34.0% in P. mirabilis. ESBLs-producing strains were more resistant to most antibiotics than non-ESBLs-producing strains. Less than 10.0% of the Enterobacteriaceae strains were resistant to imipenem or meropenem. Imipenem resistance was found in 20.2% of the P. aeruginosa 60% of the A. baumannii strains were resistant to all the antibiotics tested except cefoperazone-sulbactam. isolates. More than Conclusions Antibi otic resistance is serious in the clinical bacterial isolates in our hospital during 2012, especially, the rapidly increasing resistance level of A. baumannii to carbapenems, which is a clinical concern.