SPIROPLASMA LITORALE SP-NOV, FROM TABANID FLIES (TABANIDAE, DIPTERA) IN THE SOUTHEASTERN UNITED-STATES

Spiroplasma strain TN-1(T) (T = type strain), a strain serologically d istinct from other spiroplasma species, groups, and subgroups, was iso lated from the gut of a horsefly (Tabanus nigrovittatus) from a barrie r island off the coast of North Carolina, Related strains were isolate d from other Tabanus spp., T atratus, T. americanus, T. gladiator, T. lineola, T. sulcifrons, and T.zythicolor, from coastal Georgia, Cells of strain TN-1(T) in culture were helical and motile with an average o f 5 to 10 helical turns per cell. Electron microscopic studies determi ned that the cells of strain TN-1(T) were surrounded by a single cytop lasmic membrane, and there was no evidence of a cell wall, The spiropl asma grew well in M1D and SP-4 liquid media, Serum fraction (1%) mediu m and conventional horse serum medium also supported growth of strain TN-1(T). Fried-egg colonies were not produced; instead, the strain pro duced small diffuse colonies that were surrounded by satellite growth. The optimum temperature for growth was 32 degrees C, but multiplicati on was observed at temperatures from 10 to 41 degrees C. The doubling time at the optimum temperature (32 degrees C) was 1.6 h. No growth wa s observed at 5 or 43 degrees C. Spiroplasma strain TN-1(T) passed thr ough 220-nm filter pores but failed to pass through 100-nm filter pore s, Strain TN-1(T) catabolized glucose but hydrolyzed neither arginine nor urea, The guanine-plus-cytosine content of the DNA was about 25 +/ - 1 mol%, and the genome size was 1,370 kbp, Based on results from thi s study and previously published data, strain TN-1(T) (= ATCC 43211) ( group XVIII) is designated the type strain of a new spiroplasma specie s, Spiroplasma litorale.