血培养阳性分离菌的分布和耐药性分析

目的了解血培养主要病原菌的分布及其耐药性。方法采用MicroScan WalkAway 96 PLUS及VITEK2 compact全自动微生物鉴定及药敏系统对阳性分离菌进行鉴定及药敏试验。按CLSI 2013标准采用WHONET5.6软件进行耐药性分析,IBM SPSS 20.0进行耐药率的比较。结果 503株非重复分离菌中,革兰阳性菌占57.8%,革兰阴性菌占36.0%,真菌占6.2%。凝固酶阴性葡萄球菌（CNS）、大肠埃希菌、肠球菌属、金黄色葡萄球菌（金葡菌）和肺炎克雷伯菌是主要分离菌。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）的检出率分别为32.3%和71.7%。分离自ICU患者的CNS对多种抗菌药物的耐药率高于非ICU患者分离株（P〈0.05）。大肠埃希菌和肺炎克雷伯菌对常用头孢菌素类抗生素耐药率较高,但对哌拉西林-他唑巴坦、亚胺培南和阿米卡星耐药率低。鲍曼不动杆菌对常用抗菌药物的耐药率高。念珠菌属对抗真菌药物耐药率低。结论血培养阳性分离菌分布广泛,不同病原菌间耐药性亦不相同。应加强对血培养病原菌分布和耐药性的监测。

Distribution and antibiotic resistance of the pathogens isolated from bloodstream infections

Objective To investigate the distribution and antibiotic resistance of the pathogens isolated from blood culture . Methods Identification and antimicrobial susceptibility testing were performed with MicroScan WalkAway 96 PLUS or VITEK 2 compact .WHONET 5 .6 software was used for analysis of the susceptibility data according to CLSI 2013 breakpoints .IBM SPSS 20 .0 was employed to compare the resistance rates between groups . Results Gram-positive bacteria , gram-negative bacteria and fungi accounted for 57 .8% ,36 .0% and 6 .2% of the 503 nonduplicate isolates ,respectively .The most common isolates included coagulase-negative Staphylococcus , Escherichia coli , Enterococcus spp ., Staphylococcus aureus and K lebsiella pneumoniae . The prevalence of methicillin-resistant S . aureus （MRSA ） and coagulase-negative Staphylococcus （MRSCN） was 32 .3% and 71 .7% respectively .The coagulase-negative Staphylococcus isolates from ICU patients showed higher resistance rates to many antibiotics than those non-ICU strains （P〈0 .05） .E .coli and K .pneumoniae strains showed high percentage of resistance to cephalosporins , but relatively low resistance to piperacillin-tazobactam , imipenem and amikacin .A .baumannii isolates were highly resistant to most antimicrobial agents . Candida species were less resistant to antifungal agents .Conclusions The pathogens isolated from blood culture are diverse .The resistance profile is quite different among various pathogens .The distribution and antibiotic resistance should be actively monitored for the pathogens isolated from blood culture in order to facilitate the rational use of antimicrobial agents .