Differentiation Studies of Fecal Streptococci From Farm Animals

Employing potassium tellurite, sodium azide, and thallium acetate broths, 361 strains of fecal streptococci were isolated from 142 farm animals representing 11 species. Although none of the three media gave 100% recovery, their collective use made it possible to obtain at least one fecal streptococcus strain from every fecal sample.Results of biochemical tests revealed that 14.8% were S. bovis, 12.7% were S. faecalis var. liquifaciens, and the remaining 72.5% were atypical faecalis groups.Using the 361 isolates from animal fecal material for validating the heat resistance and heat-tellurite tolerance tests for the differentiation between animal and human fecal streptococci strains, it was found that not one of these isolates could survive these combined tests. The importance of these tests is discussed.