Mycoplasma pirum sp. nov., a Terminal Structured Mollicute from Cell Cultures

Abstract

More than 200 mycoplasma isolates recovered from a variety of contaminated cell cultures from 1968 to the present were found to belong to a distinct serological group (serogroup 38). An analysis of representative strains of this collection showed that they possessed all of the characteristics of organisms belonging to the genus Mycoplasma. These organisms were capable of fermenting glucose and of hydrolyzing arginine, and they required cholesterol or serum for growth. These organisms were unusual in that they possessed an organized terminal structure or tip, a morphological structure which has been found in at least six other species in the genus Mycoplasma. These organisms were also serologically distinct from all previously established species in the genus Mycoplasma and the genus Acholeplasma. On the basis of these findings and other morphological, biological, and serological characteristics of the strains recovered, we propose that mycoplasmas with these properties belong to a new species, Mycoplasma pirum sp. nov. Strain HRC 70-159 (= ATCC 25960) is the type strain of this species.