儿童血培养细菌的分布及污染率分析

目的了解儿童血培养细菌的分布及污染率情况，为临床判断血培养细菌结果是否为污染提供可靠依据。方法对2011年1月1日-2012年12月31日共计6530份血培养的阳性细菌结果进行分析，根据临床资料、实验室数据和微生物学3个方面鉴别其中的污染细菌。结果6530份血培养共分离出细菌314株，阳性率为4．8％。其中G＋细菌228株，以凝固酶阴性葡萄球菌为主（占43．9％），其次为金黄色葡萄球菌（占2．9％），口细菌86株，以大肠埃希菌居多（占9．6％），肺炎克雷伯菌次之（占8．3％）。其中污染细菌156株（占总检出的49．7％），以凝固酶阴性葡萄球菌为主（占31．2％），其次为芽孢杆菌属（占6．4％）。结论儿童血培养阳性污染率较高，污染以凝固酶阴性葡萄球菌为主，需综合临床和实验室的资料判定其临床意义，避免抗菌药物的不合理使用。

Distribution and Contamination Rate Analysis of Blood Culture in Children

Objective To investigate the distribution of bacteria detected from blood culture of pediatric patients and to observe the blood culture contamination rate. Methods A total of 6 530 blood samples, collected from January 2011 to December 2012 were detected by BacT/Alert 3D automated blood culture system. We found out the contamination bacteria according to clinical data, laboratory data and microbiology knowledge. Results A total of 314 bacteria strains were isolated from 6 530 blood samples, and the positive rate was 4.8%, 228 of which were gram-positive bacteria. The isolates were mainly coagulase-negative staphylococci （43.9%）, followed by Staphylococcus aureus （2.9%）. In addition, 86 cases were gram-negative bacteria, the majority of which were Escherichia coli （9.6%）, followed by Klebsiellapneumonia （8.3%）. The overall blood culture contamination rate was 49.7% （156 bacteria were identified）. The top two were coagulase-negative staphylococci （31.2%）, followed by Bacillus sp. （6.4%）. Conclusions The contamination rate is high in children＇s blood culture, and coagulase-negative staphylococci are the main bacteria. It＇s necessary to use clinical data and laboratory data to determine its clinical significance, and avoid unnecessary use of antibiotics.