SPIROPLASMA-CLARKII SP-NOV FROM THE GREEN JUNE BEETLE (COLEOPTERA, SCARABAEIDAE)

Spiroplasma strain CN-5T (T = type strain), isolated from the gut of t he cetoniine scarabaeid beetle Cotinus nitida, was serologically disti nct from other spiroplasma species, groups, and subgroups. Cells of st rain CN-5T were shown by light microscopy to be helical, motile filame nts. Cells in early passages exhibited strong translational motility t hat tended to be lost in later passages. Electron microscopy showed th at the cells were bounded by a single cytoplasmic membrane with no evi dence of a cell wall. The organism was not susceptible to penicillin. Strain CN-5T grew well in SM-1, M1D, and SP-4 liquid media and on soli d SP4 medium under aerobic or anaerobic conditions. The doubling time at 30-degrees-C, the optimum temperature, was 4.3 h. The strain also g rew in 1% serum fraction medium. Strain CN-5T produced acid from gluco se and catabolized arginine, but did not hydrolyze urea. The guanine-p lus-cytosine content of the DNA was 29 +/- 1 mol%. The genome size was 1,770 kb (1,186 MDa). Other uncloned isolates obtained from C. nitida or the cetoniine hermit flower beetle Osmoderma eremicola exhibited s imilar or identical serological patterns. Since no other hosts were di scovered in extensive studies, strain CN-5T (previously designated gro up IX) appears to represent a cluster of relatively host-specific ceto niine beetle-associated strains. Strain CN-5 (= ATCC 33827) is designa ted the type strain of a new species, Spiroplasma clarkii.