Kelly M T, Balfour L C
J Clin Microbiol. 1981 Apr;13(4):677-80. doi: 10.1128/jcm.13.4.677-680.1981.
The purpose of this investigation was to evaluate the effectiveness of the Autobac (Pfizer Inc., New York, N.Y.) urine screen for detection of bacteriuria in 3,026 urine specimens and to establish the optimum procedure for the Autobac system. Overall, 97% of urine specimens having greater than 10(5) colony-forming units (CFU) per ml were detected within 5 h by the Autobac system. The system detected 66, 90, and 94% of such specimens after 2, 3, and 4 h of incubation, respectively. Of specimens having 10(4) to 10(5) CFU/ml, the Autobac system detected 10, 45, 53, and 95% after 2, 3, 4, and 5 h of incubation, respectively. The rate of false-positive results increased from 0% after 2 h to 2% after 3 h to 6% after 4 h and 25% after 5 h of incubation. The specificity of the urine screening results also varied with the incubation time. Percentages of specimens having greater than 10(5) CFU/ml that gave positive urine screening results at various times were as follows: 96% at 2 h, 74% at 3 h, 29% at 4 h, and 9% at 5 h. These findings suggest that a 3- or 4-h urine screening procedure will effectively detect bacteriuria of greater than 10(5) CFU/ml, with few false-positive results. However, a 5-h procedure, which gives more false-positive results, may be needed for detection of lower levels of bacteriuria.
本研究的目的是评估自动细菌鉴定仪（辉瑞公司，纽约州纽约市）对3026份尿液标本中菌尿的检测效果，并确定该系统的最佳操作程序。总体而言，每毫升菌落形成单位（CFU）超过10⁵的尿液标本，97%可在5小时内被自动细菌鉴定仪系统检测到。该系统在孵育2、3和4小时后，分别能检测出此类标本的66%、90%和94%。对于每毫升含有10⁴至10⁵CFU的标本，自动细菌鉴定仪系统在孵育2、3、4和5小时后，分别能检测出10%、45%、53%和95%。假阳性结果的发生率从孵育2小时后的0%增加到3小时后的2%、4小时后的6%和5小时后的25%。尿液筛查结果的特异性也随孵育时间而变化。在不同时间给出阳性尿液筛查结果的每毫升菌落数超过10⁵的标本百分比分别为：2小时时96%、3小时时74%、4小时时29%和5小时时9%。这些结果表明，3小时或4小时的尿液筛查程序能有效检测出每毫升菌落数超过10⁵的菌尿，假阳性结果较少。然而，对于检测较低水平的菌尿，可能需要5小时的程序，但其假阳性结果更多。
