Fox H, Healing D E, George R H
Department of Microbiology, Birmingham Children's Hospital.
J Clin Pathol. 1988 Jun;41(6):683-6. doi: 10.1136/jcp.41.6.683.
A new method of blood culture, the Signal system (Oxoid), was assessed in paediatric practice. Isolation rates of pathogens, frequency of contamination (false positive results), and time taken to detect positive cultures were analysed. Four hundred and seventy nine organisms were isolated from 457 of 3000 cultures collected, of which 283 organisms were considered to be clinically important. The overall rate of positive cultures was 15.2%, and clinically important organisms were isolated from 9.1%, giving an overall contamination rate of 6.1%. The rate of contamination with Gram positive bacilli was 1.1% and coagulase negative staphylococci 4.2%. Over 51.6% of all isolates were detected within 24 hours, 81% within 48 hours, and 86% within three days: 91.1% of clinically important organisms were isolated within three days. Unimportant organisms tended to give a delayed signal, although this sometimes occurred with Candida spp, Klebsiella spp, Pseudomonas spp and a small number of other such organisms. Four hundred and forty nine of the 457 positive cultures gave a visible signal. Six of seven isolates of Haemophilus influenzae failed to give a signal, as did two coagulase negative staphylococci. The Signal system is a convenient and cost effective method of blood culture.
在儿科实践中对一种新的血培养方法——信号系统（Oxoid）进行了评估。分析了病原体的分离率、污染频率（假阳性结果）以及检测到阳性培养物所需的时间。从收集的3000份培养物中的457份中分离出479种微生物，其中283种微生物被认为具有临床重要性。阳性培养物的总体发生率为15.2%，分离出具有临床重要性的微生物的比例为9.1%，总体污染率为6.1%。革兰氏阳性杆菌的污染率为1.1%，凝固酶阴性葡萄球菌的污染率为4.2%。超过51.6%的所有分离物在24小时内被检测到，81%在48小时内被检测到，86%在三天内被检测到：91.1%具有临床重要性的微生物在三天内被分离出来。不重要的微生物往往会给出延迟信号，尽管念珠菌属、克雷伯菌属、假单胞菌属和少数其他此类微生物有时也会出现这种情况。457份阳性培养物中有449份给出了可见信号。7株流感嗜血杆菌分离物中有6株未给出信号，2株凝固酶阴性葡萄球菌也未给出信号。信号系统是一种方便且具有成本效益的血培养方法。
