Dissociation Among Lancefield's Group "B" Streptococci of Human and Bovine Origin.

Abstract

Dissociation among 26 human and 130 bovine strains of Lance-field''s group "B" streptococci was studied. Four morphological types of colony (rough, smooth, mucoid, and smooth-serried) are descr. There was no correlation between colony form and susceptibility to penicillin. All strains were resistant to strepto-mycin in vitro. Cultures from rough outgrowths of mouse viru-lent mucoid parent colonies were completely avirulent for mice. Formamide extracts of mucoid, smooth, and mucoid serried col-onies gave positive precipitin tests with commercial type O sera and extracts of rough colonies gave negative tests.