Serological Relationships of Spiroplasmas as Shown by Combined Deformation and Metabolism Inhibition Tests

Abstract

The deformation test and the metabolism inhibition test are simple and highly sensitive serological tests capable of revealing antigenic differences among spiroplasmas. Spiroplasma strains from plant and invertebrate hosts were compared in a combined deformation-metabolism inhibition test conducted in microtiter plates. Four major serological groups of spiroplasmas were recognized on the basis of deformation-metabolism inhibition tests. Group 1 was the Spiroplasma citri complex, comprised of isolates from plants, insects, and ticks. This group was provisionally divided into four serological subgroups. Subgroup 1 included the S. citri type strain (Maroc) and spiroplasmas isolated by Kondo and associates from cactus and lettuce. The second subgroup contained three corn stunt spiroplasma isolates. Subgroup 3 comprised 2 Spiroplasma strains isolated from honey bees by T. B. Clark. Subgroup 4 consisted of a single isolate (277F) from ticks. Each of these subgroups showed some serological cross-reactions with one or more of the other subgroups. Three other serologically distinct Spiroplasma clusters were observed. The suckling mouse cataract agent and an additional rabbit tick isolate (TP-2) were placed in group 2. Group 3 spiroplasmas included T. B. Clark's isolates (OBMG and BNR1) from flowers of magnolia and tulip trees. The fourth distinct serological group was represented by the uncultivated sex ratio spiroplasmas from Drosophila.