A preliminary study of delayed hypersensitivity to Mycobacterium chelonei, Mycobacterium fortuitum (Ranae) and Mycobacterium gordonae in cattle from two areas in Uganda

Abstract

In order to investigate the occurrence and significance of naturally occurring delayed hypersensitivity to 3 species of mycobacteria amongst cattle in Uganda, groups of Ankole and Zebu stock from Ankole and Karamoja districts respectively were skin tested with 3 new reagents. These reagents were prepared from strains of Mycobacterium fortuitum, M. gordonae and M. chelonei by a process of ultrasonic disruption and purification. By the use of these reagents it was shown that both M. fortuitum and M. gordonae are capable of inducing delayed hypersensitivity in cattle when common in their environment. Such reactivity did not make a major contribution to nonspecific reactivity to either “mammalian” or “avian” p.p.d.s used in the “single comparative intradermal tuberculin test”. The results also provide additional evidence that M. chelonei is not common in the soil and grass of Uganda. Taken as a whole, the results indicate that the new reagents may have a high degree of specificity justifying more extensive investigation.