Spontaneous Development of L Forms of Streptococci requiring Secretions of Other Bacteria or Sulphydryl Compounds for Normal Growth

Abstract

CERTAIN strains of non-hæmolytic streptococci, isolated in our laboratory from blood cultures of cases of subacute bacterial endocarditis and from otitis media, were found to require for their growth a substance secreted by most bacteria. They were isolated only due to the incidental presence of colonies of contaminating bacteria, around which they grew in satellite colonies. The bacterial secretion could be replaced by some sulphydryl compounds. In the absence of such substances, these strains tend to spontaneous development of L forms if an appropriate osmotic stabilizer is present in the agar medium. The sulphydryl compounds as well as the bacterial secretion seem to play a part in the formation of the cell wall of these streptococci.