Characterization of spiroplasmas by serology.

Five major serologic groups of spiroplasmas have been distinguished on the basis of serology (as determined in a test of deformation and metabolism inhibition), guanine-plus-cytosine content of DNA, and DNA-DNA hybridization. group I includes strains of Spiroplasma citri that form a classical subgroup (serovar) complex of four serologically homogeneous serovars that cross-react with each other at varying levels. The four other serogroups do not cross-react with each other or with members of the group I S. citri complex. Group II consists of the sex ratio spiroplasma from Drosophila species. Group III contains spiroplasmas isolated from flowers of magnolia and tulip trees. Group IV consists of strains of spiroplasmas recovered from insects and flowers. The tick-derived spiroplasmas SMCA and TP-2 compose group V.