为评价牛分枝杆菌纯化蛋白衍生物(purified protein derivative，PPD)单纯颈部皮内变态反应试验(single intradermal cervical tuberculin，SICT)在奶牛结核病检测中的特异性，采集54头SICT阳性牛的118份组织样品进行病原分离和鉴定。结果显示，14头SICT阳性牛样品中分离到抗酸阳性菌，占SICT阳性牛总数的25.9%(14/54)。其中，10头阳性牛样品中分离到分枝杆菌，占18.5%(10/54)；1头阳性牛样品中分离到牛分枝杆菌，占1.9%(1/54)。从118份组织样品中分离到16株抗酸阳性菌，其中12株为分枝杆菌，分枝杆菌分离率为10.2%(12/118)。12株分枝杆菌中，1株为牛分枝杆菌，其余11株为禽分枝杆菌、土地分枝杆菌等非结核分枝杆菌。牛分枝杆菌与非结核分枝杆菌分别占分枝杆菌分离株的8.3%(1/12)和91.7%(11/12)。病原分离和鉴定结果表明，SICT阳性牛的牛分枝杆菌分离率较低，为确保检测结果的准确性，有必要采用其他检测方法进行验证。同时，可将分枝杆菌快速分离培养及菌种鉴定检测技术引入对皮内变态反应试验阳性牛的实验室诊断，进一步提高牛结核病检测的特异性。

To evaluate the specificity of single intradermal cervical tuberculin (SICT) of bovine purified protein derivative (PPD) in bovine tuberculosis detection, a total of 118 tissue specimens from 54 cows with positive reaction were collected and subjected to the detection of Mycobacterium. Acid-fast bacteria strains were isolated from 14 cows and Mycobacterium strains were isolated from 10 cows. Mycobacterium bovis (M. bovis) was isolated from one cow. Sixteen acid-fast bacteria strains were isolated from 118 tissue samples and 12 strains were identified as Mycobacterium. The isolation rate of Mycobacterium was 10.2% (12/118). One strain was identified as M. bovis and the others were nontuberculous Mycobacteria (NTM), such as M. avium and M. terrace. M. bovis accounted for 8.3% (1/12) and NTM accounted for 91.7% (11/12) of all Mycobacteria respectively. The results of pathogen detection indicated a low isolation rate of M. bovis by SICT method. To ensure the accuracy of SICT, it is necessary to use more than one method to verify the results. The culture and species identification by using rapid detection techniques are recommended to be introduced into the program for tuberculosis elimination, which could improve the specificity of tuberculosis detection.