Serological typing of mycobacteria for tracing possible sources of avian mycobacterial infections in man.

Avian mycobacteria represent a potential danger to the human population in areas where effective control of tuberculosis has been achieved, but where tuberculosis is still present in poultry. During the period 1957-67, a total of 44 cases of pulmonary and non-pulmonary disease in man caused by avian mycobacteria were recorded in Czechoslovakia. The source of infection was reliably established in only a small number of cases.The strains of bacteria isolated were, therefore, subjected to serological analysis using Schaefer's method of direct agglutination of bacterial suspensions by type-specific rabbit antisera. This procedure made it possible to differentiate true avian mycobacteria (serotypes I and II) from Runyon group III nonchromogens. The majority of the cultures isolated from man, and also a large proportion of those from cattle and swine, consisted of serotypes I and II, which are those of Mycobacterium avium.The possibility of classifying avian and atypical mycobacteria by means of agglutination procedures represents a valuable tool in the study of the epidemiology of mycobacterial diseases. Evidence was presented which indicated that, in Czechoslovakia, patients with tuberculosis due to avian mycobacteria acquire their infection mainly from animal sources.