Huck W, Reed B D, French T, Mitchell R S
Hucsto, Incorporated, Microbiology Services, Salt Lake City, Utah 84102.
J Clin Microbiol. 1989 Aug;27(8):1715-8. doi: 10.1128/jcm.27.8.1715-1718.1989.
The Directigen 1-2-3 Group A Strep Test (DGAST; BBL Microbiology Systems, Cockeysville, Md.) was compared with conventional culture procedures on Trypticase soy agar with 5% sheep blood (BBL) and Selective Streptococcal Agar (ssA; BBL) for detection of group A beta-hemolytic streptococci (GABHS) for 1,006 patients complaining of sore throat. The DGAST was performed at five acute-care clinics according to the instructions of the manufacturer; interpretation of the cultures was done at the central microbiology laboratory. Of 924 patients with complete data, 243 (26.3%) were positive for GABHS on culture when both sheep blood agar and ssA were used. Of the patients with positive cultures, 159 were detected by the DGAST, yielding a sensitivity of 65.4%, a specificity of 84.7%, a positive predictive value of 60.5%, and a negative predictive value of 87.3%. The greater the number of colonies on culture, the greater the sensitivity of the DGAST, and the more intense the positive reaction on the DGAST, the higher the positive predictive value of the test. For the identification of GABHS, sheep blood agar was superior to ssA by 12.9% at 24 h and by 3.4% at 48 h of incubation.
将Directigen 1-2-3 A组链球菌检测试验（DGAST；BBL微生物系统公司，马里兰州科基斯维尔）与在含5%羊血的胰蛋白酶大豆琼脂（BBL）和选择性链球菌琼脂（ssA；BBL）上的传统培养方法进行比较，以检测1006例主诉咽痛患者的A组β溶血性链球菌（GABHS）。DGAST在五家急症护理诊所按照制造商的说明进行；培养物的解读在中央微生物实验室进行。在924例有完整数据的患者中，当同时使用羊血琼脂和ssA时，243例（26.3%）培养出GABHS阳性。在培养阳性的患者中，159例通过DGAST检测到，灵敏度为65.4%，特异性为84.7%，阳性预测值为60.5%，阴性预测值为87.3%。培养物上的菌落数越多，DGAST的灵敏度越高，DGAST上的阳性反应越强，该试验的阳性预测值越高。对于GABHS的鉴定，在培养24小时时，羊血琼脂比ssA的检出率高12.9%，在培养48小时时高3.4%。
