RT Journal Article SR Electronic(1) A1 Gourlay, R. N. A1 Leach, R. H.YR 1970 T1 A New Mycoplasma Species Isolated From Pneumonic Lungs Of Calves (Mycoplasma Dispar Sp. Nov.) JF Journal of Medical Microbiology, VO 3 IS 1 SP 111 OP 123 DO https://doi.org/10.1099/00222615-3-1-111 PB Microbiology Society, SN 1473-5644, AB SUMMARY This paper describes the isolation and characterisation of a new mycoplasma species for which the name Mycoplasma dispar is proposed. Many strains of this glucose-fermenting organism were isolated in an enriched glucose calf-serum medium from pneumonic lungs of calves, but not from healthy lungs of calves or cows. It could be isolated in medium free of known bacterial inhibitors, and when subcultured in this medium showed no evidence of reversion to bacterial forms. The general characteristics of these strains were those of mycoplasmas; these included cultural and metabolic characters, morphological appearance in stained films and electron micrographs, growth inhibition by specific antiserum and a DNA base composition of 28.5 per cent. GC. However, the group showed some unusual features, including failure to pass readily through membrane filters of 450 nm pore diameter, poor growth in conventional mycoplasma media and production of atypical colonies on GS agar medium. The serological identity of strains classified as M. dispar was demonstrated by growth and metabolic inhibition tests. They were serologically distinct from other recognised bovine mycoplasmas and from a wide range of mycoplasmas from other sources., UL https://www.microbiologyresearch.org/content/journal/jmm/10.1099/00222615-3-1-111