Significance of Mycobacterium avium subspecies avium, ‘hominissuis’#, and silvaticum, and data on their occurrence in Hungary

Abstract

SUMMARY The authors report on the occurrence of Mycobacterium avium ssp. avium, ‘Mycobacterium avium ssp. hominissuis’, and Mycobacterium avium ssp. silvaticum in Hungary. Similar to Mycobacterium avium ssp. paratuberculosis, these subspecies are also capable of provoking immunological cross-reactivity in tuberculin skin test, thus hampering the in vivo diagnosis of bovine tuberculosis. Between 2006 and 2015 the authors isolated 301 Mycobacterium avium strains which were other than M. avium ssp. paratuberculosis. Molecular biological identification methods were applied on 290 isolates, and 140 M. avium ssp. avium, 87 ‘M. avium ssp. hominissuis’ and 63 M. avium ssp. silvaticum strains were detected. From avian hosts the authors almost exclusively identified M. avium ssp. avium. In red deer and cattle ‘M. avium ssp. hominissuis’ was dominant while from swine, wild boars and red foxes M. avium ssp. avium was isolated more often. The high number of M. avium ssp. silvaticum isolates indicates the importance of this subspecies. It can be stated that beside M. avium ssp. paratuberculosis M. avium ssp. avium, ‘M. avium ssp. hominissuis’, and M. avium ssp. silvaticum are also consequently isolated from the whole geographic region of Hungary equally from domestic and wild mammals and birds. The dog and monitor lizard cases highlight the possibility of zoonotic infections, while the wild animals serve as reservoirs in maintaining and spreading these pathogens