Vila J, Gené A, García C, Vidal C, Barranco M, Escofet C, Mensa J, Jiménez de Anta M T
Servicio de Microbiología, Hospital Clínic i Provincial, Barcelona.
Med Clin (Barc). 1992 Nov 14;99(16):601-4.
To evaluate the possibility of using the determination of beta-glucuronidase and phenylalanine deaminase activity directly from urine samples for rapid detection (2 hours) of the presence of Escherichia coli and species of the Proteeae tribe.
To detect beta-glucuronidase activity methyl-umbelipheryl-beta-D-glucuronic was used as a substrate. The presence of fluorescence after incubation at 37 degrees C for 2 hours indicated a positive reaction. While phenylalanine was used as a substrate for detecting phenylalanine deaminase activity, FeCl3 was added after incubation at 37 degrees C for 2 hours with a greenish color being observed indicating phenylalanine deaminase activity.
The detection of Escherichia coli by beta-glucuronidase activity presented sensitivity and specificity of 0.91 and 0.99, respectively. The positive predictive value was 0.96 and the negative predictive value was 0.98, whereas the determination of the phenylalanine deaminase activity with the aim of detecting species of the Proteeae tribe presented the following results; sensitivity 0.92, specificity 0.99, positive predictive value 0.94 and negative predictive value 0.99.
The determination of beta-glucuronidase and phenylalanine deaminase activities directly from urine sediment has been demonstrated as a rapid and specific test for detecting the presence of Escherichia coli and species of the Proteeae tribe, therefore it must be considered as a useful test in early diagnosis of urinary infection thereby facilitating the administration of appropriate antibiotic treatment.
评估直接从尿液样本中检测β-葡萄糖醛酸酶和苯丙氨酸脱氨酶活性以快速检测（2小时）大肠杆菌和变形杆菌属细菌的可能性。
检测β-葡萄糖醛酸酶活性时，使用甲基伞形酮基-β-D-葡萄糖醛酸作为底物。在37℃孵育2小时后出现荧光表明反应呈阳性。检测苯丙氨酸脱氨酶活性时，以苯丙氨酸为底物，在37℃孵育2小时后加入FeCl3，观察到呈绿色表明有苯丙氨酸脱氨酶活性。
通过β-葡萄糖醛酸酶活性检测大肠杆菌时，敏感性和特异性分别为0.91和0.99。阳性预测值为0.96，阴性预测值为0.98，而检测变形杆菌属细菌的苯丙氨酸脱氨酶活性的结果如下：敏感性0.92，特异性0.99，阳性预测值0.94，阴性预测值0.99。
直接从尿沉渣中检测β-葡萄糖醛酸酶和苯丙氨酸脱氨酶活性已被证明是检测大肠杆菌和变形杆菌属细菌的一种快速且特异的试验，因此必须将其视为泌尿系统感染早期诊断中的一项有用试验，从而有助于给予适当的抗生素治疗。
