血培养阳性标本病原菌分布及耐药性分析

Analysis on distribution and drug-resistance of pathogens in positive blood culture

目的了解血培养阳性标本检出的病原菌分布和耐药情况,为临床医生正确选用抗菌药物提供依据。方法对某院2007年1月1日—12月31日临床送检的2317份血培养标本,采用BACTEC9120全自动血培养仪培养,BioMerieux API系统鉴定菌种,K-B纸片扩散法进行药敏试验。数据以WHONET 5.3软件进行统计分析。结果血培养标本培养阳性324份,共223人,分布55个病房,阳性率为13.98%。检出细菌26种,真菌3种,共计病原菌223株。其中,革兰阳性球菌109株(48.88%),革兰阴性杆菌106株(47.53%),假丝酵母菌属8株(3.59%);居前4位的感染病原菌依次为凝固酶阴性葡萄球菌67株、大肠埃希菌41株、肺炎克雷伯菌20株、金黄色葡萄球菌15株。中心重症监护室(ICU)、急诊科病房、血液科病房分离菌所占比率分别为21.97%、14.80%、14.35%。凝固酶阴性葡萄球菌中耐甲氧西林菌株(MRCNS)占73.13%,金黄色葡萄球菌中耐甲氧西林菌株(MR-SA)占40.00%,大肠埃希菌和肺炎克雷伯菌的超广谱β-内酰胺酶(ESBLs)检出率分别为41.46%、30.00%;MRC-NS、MRSA及产ESBLs菌株的耐药率均较高。结论血培养阳性标本检出病原菌种类复杂,耐药率高,临床医生应加强对疑似败血症患者血液中病原菌的检测,以合理选用抗菌药物。

Objective To investigate the distribution and drug-resistance of pathogens in positive blood culture, so as to provide reference for the rational use of antimicrobial agents. Methods From January 1, 2007 to December 31,2007, a total of 2 317 blood samples were cultured by BACTEC9120 system, the isolates were identified by API system, drug sensitive tests were performed by Kirby-Bauer test, the data were analyzed by WHONET5.3 software. Results Two hundred and twenty-three patients in 55 clinical wards had 324 positive blood culture, the positive rate was 13.98 %. The isolated strains include 26 species of bacteria and 3 species of fungi, there were 223 pathogenic strains in total. Gram-positive cocci, gram-negative bacilli and Candida were 109 （48.88% ） strains, 106 （ 47.53 % ） and 8 （ 3.59% ） respectively; The main pathogenic bacteria were Coagulas-negative staphylococcus （67 strains）, Escherichia coli （41 ）, Klebsiella pneurnoniae （20） and Staphylococcus aureus （15）. The percentage of isolated bacteria in intensive care unit, emergency department and hematological department was 21.97 %, 14.80 % and 14.35% respectively. Methicillin-resistant Coagulase negative staphylococcus （MRCNS） and methieillin-resistant Staphylococcus aureus （MRSA） accounted for 73. 13 % and 40.00 % respectively. The detection rate of extended-spectrum 13-1actams （ESBLs） of Escherichia coli and K lebsiella pneumoniae was 41. 46% and 30. 00% respectively; Drug-resistant rate of MRCNS, MRSA and ESBLs-produeing strains were all high. Conclusion There are varieties of pathogens isolated from blood culture, and the drug resistance of pathogens are high, clinicians should pay attention to the culture of blood in patients suspected septicemia, so as to use antimicrobial agents rationally.