[Sources of cattle infection with atypical mycobacteria and the frequency of their isolation from healthy slaughter animals in Cienfuegos Province, Cuba].

Studied were a total of 322 samples of water, feed, and grass vegetation with soil from a region where there were records of unspecific tuberculin reactions with cattle. Investigations were also carried out on viscera and lymph nodes of 120 slaughtered cattle. It was found that the atypical acid-fast mycobacteria were widely spread in some regions of Cuba: 42.5% were found in grass samples, 37.5%--in soil samples, 35.0%--in water ones, and 9.6% in feed samples. Atypical mycobacteria were isolated in 35.0% of the cases with internal organs and lymph nodes of slaughtered healthy animals. Established were as many as ten species of such bacteria, prevailing being M. aquae B, M. aquae A, M. smegmatis, and M. phlei. Suggested is the preparation of an allergen from selected strains of atypical mycobacteria to carry out differential tuberculin tests where suspected tuberculin reactions were recorded in the practice.