不同送检模式下血培养阳性率与病原菌的分布

Blood culture positive rate and distribution of pathogens with different submission methods

目的：了解不同送检模式的血培养阳性率与病原菌的分布状况。方法：采用BD FX400全自动血培养仪对2013年全年送检的血液标本进行培养,阳性标本做病原菌鉴定,对不同送检模式血培养阳性率与病原菌进行分析。结果：5.565份血培养标本,培养出687株病原菌,阳性率为12.3%（687/5 565）;其中双侧双瓶血培养送检率为87.6%（4 875/5 565）,阳性率为12.8%（624/4 875）,明显高于单侧单瓶的阳性率9.0%（30/335）（χ^2=0.0025,P〈0.005）及双侧单瓶的阳性率9.3%（33/355）,但与后者比较无统计学意义。双侧双瓶和双侧单瓶血培养病原菌检出率最高的均为大肠埃希菌,分别为27.6%（172/624）和30.3%（10/33）;而单侧单瓶血培养病原菌检出率最高的则为凝固酶阴性的葡萄球菌,占40%（12/30）,此菌在双侧双瓶和双侧单瓶病原菌中各占12.8%（80/624）和18.2%（6133）。在双侧双瓶标本分离的624株病原菌中,有了7株仅在厌氧瓶中生长,占血培养总菌株11.2%（77/687）。结论：双侧双瓶血培养送检模式提高了血培养阳性率,降低了漏检率,有利于提高血培养检验质量。

Objective： To understand the effect of different submission methods on blood culture positive rate and the distribution of pathogens. Methods： Blood culture of blood specimens submitted in 2013 was performed with BD FX400 automated blood cttlture system. Characterization of pathogens was further performed for positive specimens. Blood culture positive rate and the distribution of pathogens with different submission methods were analyzed. Results： A total of 687 pathogens were found from 5 565 blood specimens with a positive rate of 12.3% （687/5 565）, where bilateral double bottles submission accounted for 87.6% （4 875/5 565） with a positive rate of 12.8% （624/4 875）. The positive rate of blood culture with bilateral double bottles was significantly higher than that with unilateral single bottle of 9.0% （30/335） （~=0.0025, P〈0.005） and that with bilateral single bottle of 9.3% （33/355）. However, there was no statistical difference in positive rate between bilateral double bottles and bilateral single bottle. Escherichia coli was the pathogen with the highest detection rate, which was 27.6% （172/624） and 30.3% （10/33） for bilateral double bottles and bilateral single bottle, respectively. With regard to unilateral single bottle, coagulase-negative staphylococci were the mostly detected pathogen, accounting for 40% （12/30）. The detection rate of coagulase-negative staphylococci in blood cultures with bilateral double bottles and bilateral single bottles were 12.8% （80/624） and 18.2% （6/33）, respectively. Among the 624 pathogens isolated with bilateral double bottle specimens, 77 could only grow in anaerobic conditions, accounting for 11.2% of blood culture isolates total （77/687）. Conclusion： Bilateral double bottle submission methods can increase blood culture positive rate with a decrease in undetected rate, which will help to improve the quality of blood culture tests.