血培养不同报警时间段与分离菌株种类的关系

Distibution of pathogens bacteria isolated from blood specimens and association between the equipment alarm of blood culture and the bacteremia

目的:了解血培养阳性分离菌的种类和分析仪器报警时间与菌血症之间的关系。方法:对本院收集到的2054份血培养标本进行回顾性分析。结果:2054份血培养标本中198份阳性,其中革兰阳性球菌占67.2%,革兰阴性杆菌占32.8%,分离株以凝固酶阴性葡萄球菌和大肠埃希菌为主,主要分布在新生儿科、重症监护室。导致菌血症的病原菌共96株,主要集中在12 h～24 h,为57例。在报警时间<12 h、12 h～24 h、24 h～48 h、48 h～72 h间病原菌比率依次为84.2%6、3.3%、34.8%、20.0%,不同阳性报警时间的病原菌比率有明显差异(χ2=32.138,P=0.000)。结论:血培养阳性报警的污染菌比率很高,血培养瓶中原始菌量越少,达到报警阈值的培养时间就越长,是污染菌的可能性就越大,应严格无菌操作,结合报警时间和临床资料,避免抗生素的滥用。

Objective： To investigate the types of blood cultured positive isolates and the relationships between the equipment alarm time of their growth and the bacteremia.Methods： A retrospective analysis of 2054 blood culture samples was done.Results： 198 blood culture positive samples were isolated from the 2054 culture blood samples,Gram-poitive coccus accounted for 67.2%,Gram-negative bacillus accounted for 32.8%,the isolates were mianly coagulase-negative staphylococcus and Escherichia coli,mainly distributed in the units of neonatology and ICU.The pathogens which leaded to the bacteremia were totally 96 strains,mainly concentrated in 12 h～24 h with 57 strains.The rates of the pathogens were accordingly 84.2%,63.3%,34.8%,20.0% when the equipment alarm time of their growth were 12 h,12 h～24 h,24 h～48 h,48 h～72 h.The rates of pathogens were significantly different in different equipment alarm times（χ2=32.138,P=0.000）.Conclusion： The positive culture rate of contaminants was very high,the less the amount of original bacteria,the longer the culture time to reach the alarm threshold,the greater the likelihood of contaminants would be,we should take aseptic technique and integrate equipment alarm time and the clinical datas to avoid the abuse of the antibiotics.