Isolation of Mycobacterium kansasii from lymph nodes of cattle in the United States

The isolation of 6 strains of Mycobacterium kansasii from bovine lymph nodes is reported. Occasional isolations of this organism from cattle lymph node lesions provides further evidence of its pathogenicity in domestic animals. The isolates were similar as determined by biochemical and serologic examinations. Histopathologic changes induced by this organism relative to those by M bovis and factors regarding source of infection are discussed.