Holland R L, Cooper B H, Helgeson N G, McCracken A W
J Clin Microbiol. 1980 Aug;12(2):180-4. doi: 10.1128/jcm.12.2.180-184.1980.
Sterile stainless-steel electrodes implanted in blood culture bottles and monitored electronically were used to detect growth of microorganisms. Each blood culture bottle contained 100 ml of medium and was inoculated with 10 ml of blood seeded with either 300 or 50 colony-forming units of one of several bacterial or yeast species that are commonly isolated from clinical blood cultures. Growth was indicated by a voltage change of at least 0.1 mV/min with an increasing slope over at least three consecutive 15-min intervals. This method was compared to the conventional visual method for detecting microbial growth in broth. Growth detection by both techniques was confirmed by subculture to solid media. Of the 163 cultures seeded with the high inoculum (300 colony-forming units) and confirmed as being positive, 148 (90.8%) were positive by the electronic detection system (EDS). At the lower inoculum (50 colony-forming units), 47 of 53 (88.7%) positive cultures were detected by EDS. Twelve of the 21 false-negatives by the EDS were cultures seeded with Cryptococcus neoformans. Excluding C. neoformans, the rate of detection of growth was 96.0%. Microbial growth was detected an average of 18 h earlier by EDS than by the conventional system in 176 (90.2%) of the cultures. Also examined were 156 patient blood cultures: 13 were positive both by EDS and by conventional methods.
将无菌不锈钢电极植入血培养瓶并进行电子监测，以检测微生物的生长。每个血培养瓶含有100毫升培养基，并接种10毫升血液，血液中接种了从临床血培养中常见分离出的几种细菌或酵母菌种之一的300个或50个菌落形成单位。生长的标志是电压变化至少为0.1 mV/分钟，且在至少三个连续的15分钟间隔内斜率增加。该方法与用于检测肉汤中微生物生长的传统视觉方法进行了比较。两种技术的生长检测均通过转种到固体培养基上得以证实。在接种高接种量（300个菌落形成单位）并被确认为阳性的163份培养物中，电子检测系统（EDS）检测出148份（90.8%）为阳性。在低接种量（50个菌落形成单位）时，EDS检测出53份阳性培养物中的47份（88.7%）。EDS检测出的21例假阴性培养物中有12份接种了新型隐球菌。排除新型隐球菌后，生长检测率为96.0%。在176份（90.2%）培养物中，EDS检测到微生物生长的时间平均比传统系统早18小时。还对156份患者血培养物进行了检查：13份通过EDS和传统方法检测均为阳性。
