TAXONOMIC DESCRIPTIONS OF 8 NEW NON-STEROL-REQUIRING MOLLICUTES ASSIGNED TO THE GENUS MESOPLASMA

Twenty mollicute strains isolated primarily from insect hosts were cha racterized and arranged into eight new species in the genus Mesoplasma . Morphological examination of the organisms by electron and dark-fiel d microscopic techniques revealed that the cells of each strain were s mall, nonhelical, nonmotile, pleomorphic, and coccoid and that each ce ll was surrounded by a single cytoplasmic membrane,vith no evidence of a cell wall. Although the new mollicutes grew well in media containin g horse or fetal bovine serum, growth in serum-free or cholesterol-fre e medium occurred only when the medium contained 0.04% polyoxyethylene sorbitan (Tween 80). The optimum temperature for growth was usually 3 0 degrees C, but multiplication generally occurred over a temperature range of 10 to 32 degrees C. All strains catabolized glucose. Most str ains did not hydrolyze arginine or urea, although three related strain s isolated from fireflies (the strain PUPA-2(T) [T = type strain] grou p) did hydrolyze arginine. The genome sizes ranged from 825 to 930 kbp , and the DNA base compositions (guanine-plus-cytosine contents) range d from 26.5 to 31.6 mol%. The proposed type strains of the eight new s pecies were not serologically related to the type strains of four othe r Mesoplasma species, five Entomoplasma species, 11 Acholeplasma speci es, and 100 Mycoplasma species and subspecies. Strain PS-1 (= ATCC 495 82) is the type strain of Mesoplasma pleciae sp. nov., strain PUPA-2 ( = ATCC 49581) is the type strain of Mesoplasma photuris sp. nov., stra in YJS (= ATCC 43706) is the type strain of Mesoplasma syrphidae sp. n ov., strain CHPA-2 (= ATCC 49578) is the type strain of Mesoplasma cha uliocola sp. nov., strain ELCA-2 (= ATCC 49579) is the type strain of Mesoplasma corruscae sp. nov., strain GRUA-1 (= ATCC 49580) is the typ e strain of Mesoplasma grammopterae sp. nov., strain BARC 779 (= ATCC 49583) is the type strain of Mesoplasma coleopterae sp. nov., and stra in BARC 857 (= ATCC 49584) is the type strain of Mesoplasma tabanidae sp. nov.