EN
The problem of infections with bacilli from the genus Mycobacterium is a still current issue both for human and animal pathology. The progress that has been made in mycobacteriology has brought about the discovery of many new Mycobacterium species of lower or higher pathogenicity for vertebrates. Mycobacterium genavense was discovered in 1992 in Germany. It was isolated for the first time from patients infected with HIV, who, due to a significantly impaired immune system, are particularly exposed to infections with acid-fast bacilli. Most frequently, however, M. genavense infections are found in birds. For them the bacillus is among the main causative agents of mycobacteriosis, ranking in the second place after Mycobacterium avium. Such a late discovery of this bacilli must have resulted from the fact that its isolation in artificial media is very difficult. In relation to the above the bacilli is suspected of being responsible for the disease cases where acid-fast bacilli were not isolated on artificial media but they were present in preparations stained by Ziehl-Nielsen method. Only the application of highly specific media and, primarily, achievements in molecular biology have enabled the diagnosis of infections caused by this bacilli.