MORPHOLOGIC INSTABILITY OF ACTINOMYCETES ASSOCIATED WITH ENAMEL

¹ University of California, College of Dentistry, Division of Oral Pathology, San Francisco, Calif.

In actinomycete cultures obtained from enamel surfaces, coccoidal cells were found to be intimately associated with the filamentous cells. Direct observation on cell division and growth showed that the coccoidal cells produced filamentous cells and were, therefore, pleomorphic forms. In other respects the morphology of these actinomycetes corresponded closely to those of 0rskov's Group IIb and to those of the Wolff-Israel type. The pleomorphism of these strains indicates that actinomycetes cultivated from enamel sometimes may be difficult to distinguish from the diphtheroids and cocci common among the oral flora. This pleomorphism further suggests that the filamentous and coccoidal forms observed histologically in preclinical various enamel lesions may be actinomycetes.