ORAL STRAINS OF ACTINOMYCES

Abstract

A comparison was made of 200 strains of Actinomyces isolated from the oral cavity of humans in the absence of clinical actinomycosis with 11 strains isolated from lesions. The comparisons were made on the basis of colony morphology on initial isolation plates, growth in fluid thioglycolate medium, morphology of micro- and macrocultures on brain heart infusion agar, growth on each of 16 carbohydrates, oxygen tolerance, and certain other physiological tests. It was found that the oral strains were of 2 main types. One corresponds morphologically to A. naeslundii (not generally accepted as a valid species) proposed by Thompson and Lovestedt (1951). It was proposed that A. naeslundii, Thompson and and Lovestedt, be accepted as the proper name for these fast growing, relatively oxygen tolerant, oral strains of Actinomyces. The 2nd type is essentially identical to strains isolated from lesions and should be designated as A. israelii.