Spiroplasma syrphidicola sp. nov., from a Syrphid Fly (Diptera: Syrphidae)

Spiroplasma sp. strain EA-1T (T = type strain) (subgroup VIII-1), which was isolated from the syrphid fly Eristalis arbustorum, was serologically distinct from other spiroplasma species, groups, and subgroups. The cells of this strain, as revealed by dark-field light microscopy, were short, helical, and motile. An electron microscopic examination revealed wall-less cells delimited by a single membrane. The unusually short cells passed through 220-nm filter pores with no reduction in titer. The organisms grew well in SM-1, MID, and SP-4 liquid media. Growth also occurred in conventional horse serum medium and 1% serum fraction medium. Strain EA-1T grew at temperatures between 10 and 41°C, and optimuum growth occurred at 32°C. The doubling time at the optimal temperature was 1.0 h. The strain catabolized glucose and hydrolyzed arginine but did not hydrolyze urea. The guanine-plus-cytosine content of the DNA was 30 ± 1 mol%. The genome size was about 1,230 kbp. Strain EA-1 (= ATCC 33826), which represents subgroup VIII-1, is designated the type strain of a new species, Spiroplasma syrphidicola.