单中心2006至2009年血流感染病原菌的临床分布特征及耐药性分析

Clinical distribution and drug resistance of pathogens causing bloodstream infections in a single center from 2006 to 2009

目的了解引起血流感染（BSI）病原菌的临床分布特征及耐药性，为指导临床合理用药提供依据。方法用BacT／ALERT3D微生物全自动检测系统对血进行培养检测。用VITEK．2全自动微生物鉴定仪对病原菌进行鉴定及药物敏感性检测。以Whonet5．4软件进行数据统计分析，通过查阅病历了解住院患者的临床资料。结果2006至2009年中山大学孙逸仙纪念医院共收检血培养标本10462份，检出病原菌830株，阳性率为7．9％，其中革兰阴性杆菌442株，占53．3％（442／830），以大肠埃希菌为主，占33．7％（149／442）；革兰阳性球菌275株占33．2％（275／830），以凝固酶阴性葡萄球菌（CONS）为主，占44．4％（122／275）；真菌113株，占13．6％（113／830），以热带念珠菌为主，占24．8％（28／113）。引起BSI的病原菌中，大肠埃希菌居首位（18．0％），其次为凝固酶阴性葡萄球菌（14．7％）、肺炎克雷伯菌（8．2％）。产超广谱β-内酰胺酶大肠埃希菌和肺炎克雷伯菌分别为67．5％和49．1％。碳青酶烯类及阿米卡星对肠杆菌科细菌有较好的抗菌活性，左氧氟沙星对常见非发酵菌的体外抗菌活性较好。耐甲氧西林金黄色葡萄球菌和耐甲氧西林凝固酶阴性葡萄球菌的检出率分别为53．2％和88．5％，未发现耐万古霉素革兰阳性球菌。血流感染患者临床分布以ICU、儿科和血液科为主，分别为25．5％、22．2％和12．4％，其基础疾病以恶性肿瘤、血液病多见，分别为26．8％、20．6％。结论该院血流感染病原菌主要为大肠埃希菌，其次是凝固酶阴性葡萄球菌和肺炎克雷伯菌。万古霉素、替考拉宁、利奈唑烷及奎奴普丁或达福普汀对革兰阳性球菌有较好的抗菌活性；碳青酶烯类及左氧氟沙星对革兰阴性杆菌有较好的抗菌活性。有恶性肿瘤、血液病等基础疾病者易发生血流感染。

Objective To investigate the clinical distribution and drug resistance of pathogens causing bloodstream infection （BSI） , and to guide reasonable use of antibiotics in clinical practices. Methods A BacT/ALERT 3D fully automatic microbe detection system was used for blood culture, and VITEK- 2 fully automatic system for pathogen identification and drug sensitivity test. The results were collected and analyzed using Whonet 5.4 software. Medical records were retrieved for clinical data of the patients during hospital stay. Results From 10 462 blood culture specimens collected in Sun Yatsen Memorial Hospital of Sun Yat-sen University from 2006 to 2009, 830 strains of pathogens （overall positive rate： 7.9% ） were identified, including 442 strains （53.3%） of Gramnegative bacilli （GNB） with predominating E.coli [ 149/442, 33.7% ], 275 strains （33.2%） of Gram-positive cocci with predominating eoagulase- negative staphylococci （CONS） [122/275, 44.4% ] , and 113 strains （13.6%） of fungi with predominating Candida tropicalis [28/113, 24.8% ]. The most common pathogens that caused BSI was E.coli （18.0%）, followed by CoNS （14.7%） and Klebsiella pneumoniae （8.2%）. ESBLs production was found in 67.5% and 49.1% of E.coli and Klebsiella pneumoniae strains respectively. Carbapenems and amikacin （AMK） showed favorable antibacterial activity against enterbacteriaceae, while levofloxacin （LVFX） showed favorable, in vitro antibacterial activity against common non-fermenters. The detection rate for MRSA and MRCoNS was 53.2% and 88.5% respectively. Vancomycin-resistance Gram positive cocci were not detected. ICU, departments of pediatrics and hematology were major sources of clinical distribution （25.5%, 22.2% and 12.4% ）. The underlying diseases in patients with bloodstream infections mainly included malignant tumor （26.8%） and hematopathy （20.6%）. Conclusion In our hospital, the most common BSI-causing pathogens are E.coli, followed by CoNS and Klebsiella pneumonia. Vancomycin, teicoplanin, and quinupristin/dalfopristin show favorable antibacterial activity against Gram-positive cocci, as do carbapenems and LVFX against Gram-negative bacilli. Subjects with underlying malignant tumor or hematopathy are more likely to develop bloodstream infections.