[Biological characteristics of Salmonella typhimurium obtained from different sources 1975-1980]

Distinct differences in a number of biological properties between S. typhimurium hospital strains and cultures of animal origin have been revealed. During 1975-1980 changes in the fermentation of lysine were observed in hospital strains and the retarded fermentation of sorbitol was revealed in strains of animal origin. S. typhimurium 1R, a new highly virulent biovariant resistant to antibiotics, and enzymatic varieties of biovar 11S were isolated. The nonstability of enzymatic differences between hospital strains and cultures of animal origin necessitates their constant observation in order to differentiate these cultures for the purpose of epidemic analysis. Complete correlation between the properties of cultures circulating on a limited territory and the character of morbidity in Salmonella infection demonstrates the epidemiological importance of the intraspecific differentiation tests under study.