Spiroplasma Chrysopicola Sp. Nov, Spiroplasma Gladiatoris Sp. Nov, Spiroplasma Helicoides Sp. Nov, And Spiroplasma Tabanidicola Sp. Nov, From Tabanid (Diptera: Tabanidae) Flies

Four spiroplasma strains, DE-1(T), TG-1(T), TABS-2(T), and TAUS-1(T), all of which were isolated from deerflies or horseflies (Diptera: Tabanidae), were serologically distinct from previously described spiroplasma species, groups, and subgroups. Strain DF-1(T) originated from a Maryland deerfly (Chrysops sp.); strain TG-1(T) was isolated from a Maryland horsefly (Tabanus gladiator); strain TAUS-IT originated from a member of the Tabanus abdominalis-limbatinevris complex of horseflies collected in Maryland; and strain TABS-2(T) was isolated from a horsefly (Tabanus abactor) collected in Oklahoma. Cells of all of the strains appeared to be helical and motile when they were examined by dark-field microscopy. Cells of strain DF-1(T) growing in M1D medium were short helices with less than six turns; the helical cells of the other strains were long and usually had six or more turns. The short cells of strain DF-1(T) passed through 450- and 300-nm filter pores with no reduction in titer, but the longer cells of the other strains were partially retained by 450-nm-pore-size filters. Electron microscopic examination of all of the strains revealed wall-less cells surrounded only by a single cytoplasmic membrane. All of the strains grew well in SP-4 liquid media and in conventional mycoplasma or M1D media supplemented with horse or fetal bovine serum. Strains TABS-2(T), TAUS-1(T), and DF-1(T) required serum or sterol for growth, but strain TG-1T was able to grow in the absence of serum or sterol. The optimum temperatures for growth of the four strains varied from 30 to 32 degrees C, and growth occurred at 10 to 37 degrees C. All of the strains catabolized glucose but did not hydrolyze urea. Only strain DF-1(T) hydrolyzed arginine. The guanine-plus-cytosine contents of the DNAs of the strains were: DF-1(T), 29 + 1 mol%; TG-1(T), 26 +/- 1 mol%; TABS-2(T), 27 +/- 1 mol%; and TAUS-1(T), 26 +/- mol%. The genome sizes of strains DF-1(T) and TAUS-1(T) were 1,270 and 1,375 kbp, respectively. Strain DE-1 (= ATCC 43209), the representative of spiroplasma subgroup VIII-2, is designated the type strain of a new species, Spiroplasma chrysopicola. We also propose that strain TG-1(T) (= ATCC 43525(T)), the designated representative of group XXIII, should be placed in a new species, Spiroplasma gladiatoris. In addition, group XXXII spiroplasma strain TABS-2 (= ATCC 51746) is designated the type strain of Spiroplasma helicoides sp. nov., and group XXXIII representative strain TAUS-1 (= ATCC 51747) is designated the type strain of another new species, Spiroplasma tabanidicola.