Characteristic abnormal cell forms of some microorganisms: A contribution to taxonomy

Abstract

The effect of penicillin upon morphology was studied with two species of bacteria and with streptococci. The morphology of Miyagawanella psittaci varied considerably under the influence of penicillin in contrast to the lack of such effect upon viruses. Classification of miyagawanellae outside the viruses is justified. Appropriate dosages of penicillin induced extensive branching in Lactobacillus bifidus. This contrasted with the lack of such effect upon L. acidophilus. Removal from the family Lactobacillaceae is justified and indicates relationship to the actinomycetes. Cells of five species of the streptococcus showed development of oval and elongated forms while four strains of micrococci revealed changes in size and not in shape. This indicates lack of close relationships between streptococci and micrococci.