Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
J Microbiol Immunol Infect. 2010 Apr;43(2):126-32. doi: 10.1016/S1684-1182(10)60020-5.
BACKGROUND/PURPOSE: Identifying the pathogens present in blood stream infections is crucial to initiate appropriate antimicrobial therapy and avoid morbidity and mortality. The aim of this study was to evaluate the effect of overnight storage of aerobic and anaerobic BACTEC 9240 blood culture bottles on the detection time for common pathogens.
From November 2007 to July 2008, a total of 2,105 isolates were positively detected using the BACTEC 9240 system. The time to positive detection (TTD) was calculated by subtracting the time of receipt in the laboratory from the time required to detect a positive culture. The mean TTD values were calculated using the TTD value of the first positive culture bottle only. Overnight delay at the National Cheng Kung University Hospital, Taiwan was 15 hours (from 5 pm to 8 am).
Of the 2,105 total isolates, 972 (46.1%) were Gram-positive bacteria, 1,024 (48.6%) were Gram-negative bacteria and 109 (5.1%) were fungi. Among the top 10 pathogens, 24.7% grew only in the aerobic bottle and 15.1% in the anaerobic bottle, including Staphylococcus spp., Enterococcus faecium, Enterobacteriaceae, and Gram-positive bacilli. Due to the overnight delay in loading a blood culture bottle into the instrument, for most of the pathogens (including Staphylococcus spp. and Enterobacteriaceae), a decrease in TTD by <or= 4.4 hours was observed. An increase in TTD by 20.8 hours was observed for Gram-positive bacilli. We also found that the difference between TTD in aerobic versus anaerobic bottles during the day was higher in coagulase-negative staphylococcus (12 hours) and lower in Escherichia coli and Staphylococcus aureus (< 2 hours). TTD was longer than 72 hours in 20.5% of Gram-positive bacilli and 7.3% of Candida albicans.
No difference in the TTD of major pathogens was observed in bottles processed during the day and after overnight delay, suggesting that the delayed entry of the blood culture bottle into the instrument may affect the detection time. Since high numbers of facultative anaerobes were detected in anaerobic bottles only, use of a single aerobic bottle might have a detrimental effect on the clinical therapy outcome.
背景/目的：鉴定血流感染中的病原体对于启动适当的抗菌治疗以及避免发病率和死亡率至关重要。本研究的目的是评估有氧和厌氧 BACTEC 9240 血培养瓶隔夜储存对常见病原体检测时间的影响。
2007 年 11 月至 2008 年 7 月，使用 BACTEC 9240 系统共检测出 2105 株阳性分离株。通过从实验室收到的时间减去检测到阳性培养物所需的时间来计算阳性检测时间（TTD）。仅使用第一个阳性培养瓶的 TTD 值计算平均 TTD 值。在台湾成功大学医院，隔夜延迟时间为 15 小时（从下午 5 点到上午 8 点）。
在 2105 株总分离株中，972 株（46.1%）为革兰阳性菌，1024 株（48.6%）为革兰阴性菌，109 株（5.1%）为真菌。在排名前 10 的病原体中，24.7%仅在有氧瓶中生长，15.1%在厌氧瓶中生长，包括葡萄球菌属、屎肠球菌、肠杆菌科和革兰阳性杆菌。由于夜间将血培养瓶装入仪器的延迟，对于大多数病原体（包括葡萄球菌属和肠杆菌科），TTD 减少了<或=4.4 小时。革兰阳性杆菌的 TTD 增加了 20.8 小时。我们还发现，白天有氧瓶与厌氧瓶之间的 TTD 差异在凝固酶阴性葡萄球菌中更高（12 小时），在大肠杆菌和金黄色葡萄球菌中更低（<2 小时）。20.5%的革兰阳性杆菌和 7.3%的白色念珠菌的 TTD 超过 72 小时。
在白天和隔夜延迟处理的瓶子中，主要病原体的 TTD 没有差异，这表明血培养瓶延迟进入仪器可能会影响检测时间。由于仅在厌氧瓶中检测到大量兼性厌氧菌，因此使用单个有氧瓶可能会对临床治疗结果产生不利影响。
