Detection of nontuberculous mycobacterial species using PCR-Restriction Analysis in trans-tracheal washes in cattle and buffaloes with respiratory distress

Document Type: Short paper


Department of Veterinary Microbiology College of Veterinary Science, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana-141004, Punjab, India



Background: Bovine tuberculosis (bTB) is a chronic disease of cattle with high economic importance in livestock farming caused by Mycobacterium bovis and bears a zoonotic potential. There are some nontuberculous mycobacteria (NTM) which cause disease similar to bTB and interfere with diagnosis of bTB. NTM are saprophytic in nature but some of them may cause pulmonary infections, mastitis lesions in respiratory tract and lymph nodes of cattle, due to which they are being recognized worldwide and interfere with the diagnosis of bovine tuberculosis. Aim: The aim of the study was to detect nontuberculous mycobacterial species from cattle and buffaloes with respiratory distress using biochemical test and PCR-Restriction Analysis (PRA). Method: A total of 50 trans-tracheal washes were collected from cattle (n=41) and buffaloes (n=9) with respiratory distress. The samples were inoculated on Middlebrook 7H10 media after proper decontamination with 4% NaOH. The isolate obtained was identified by biochemical testing. Extracted DNA from samples and isolate was subjected to PRA (PCR-RFLP) which involved hsp65 gene amplification (439bp) and restriction analysis of amplified product. Results: Out of 50 trans-tracheal washes only one isolate of M. kansasii (n=1) (2%) was obtained which was confirmed by biochemical testing and PRA. M. kansasii (n=4) (8%), M. intracellulare (n=1) (2%) and M. vaccae (n=1) (2%) were identified by PRA. Conclusion: The study emphasizes the importance of NTM in animals.PRA is more reliable and rapid method for identification of NTM than conventional methods.