Hale D C, Wright D N, McKie J E, Isenberg H D, Jenkins R D, Matsen J M
J Clin Microbiol. 1981 Jan;13(1):147-50. doi: 10.1128/jcm.13.1.147-150.1981.
A total of 2,720 urine specimens from three laboratories were evaluated by Autobac (Pfizer Diagnostics) and were compared with simultaneous colony counts for evidence of bacteriuria. Of 599 specimens with a colony count of greater than or equal to 10(5) colony-forming units per ml, 93.8% were detected within 6 h. This detection rate increased to 97% of 447 positive urine specimens when only specimens from patients not on antimicrobials were evaluated. The majority (77.9%) of positive specimens were detected as early as 3 h. Those specimens with greater than or equal to 10(5) colony-forming units per ml, which were negative by Autobac at 6 h, included organisms which are frequently considered to be contaminants (diphtheroids, lactobacilli, alpha and gamma streptococci, yeasts, and Staphylococcus epidermidis), or were from patients who were being treated with antimicrobial agents. Of 2,121 urine specimens with colony counts of less than 10(5), 98.1% were correctly determined to be negative by Autobac at 3 h. This percentage decreased to 86.0 at 6 h. The majority of these false-positive specimens were those with colony counts of 10(4) to 10(5) colony-forming units per ml. There appeared to be no major difference in results from the three laboratories or among the four lots of broth used in this study.
来自三个实验室的总共2720份尿液标本由Autobac（辉瑞诊断公司）进行评估，并与同时进行的菌落计数相比较，以确定是否存在菌尿。在599份菌落计数大于或等于每毫升10⁵菌落形成单位的标本中，93.8%在6小时内被检测出来。当仅评估未使用抗菌药物患者的标本时，447份阳性尿液标本的检测率提高到97%。大多数（77.9%）阳性标本在3小时时就被检测出来。那些每毫升菌落形成单位大于或等于10⁵、在6小时时Autobac检测为阴性的标本，包括通常被认为是污染物的微生物（类白喉杆菌、乳酸杆菌、α和γ链球菌、酵母菌以及表皮葡萄球菌），或者来自正在接受抗菌药物治疗的患者。在2121份菌落计数小于10⁵的尿液标本中，98.1%在3小时时被Autobac正确判定为阴性。在6小时时，这一比例降至86.0%。这些假阳性标本大多数是菌落计数为每毫升10⁴至10⁵菌落形成单位的标本。在本研究中，三个实验室的结果或所用四批肉汤之间似乎没有重大差异。
