Application of dot immunobinding on membrane filtration (MF dot) to the study of relationships within "M. mycoides cluster" and within "glucose and arginine-negative cluster" of ruminant mycoplasmas.
A total of 189 isolates from cattle, sheep and goats, allocated to 2 groups on biochemical grounds, were examined by a dot immunobinding membrane-filtration (MF dot) method. 70 glucose fermenting isolates, showing relationships with the "Mycoplasma mycoides cluster", were compared by MF dot against polyclonal hyperimmune sera prepared against the following reference strains. M. mycoides subsp. mycoides, small colony type (SC), strain PG1 and large colony type (LC) strain Y Goat; M. capricolum strain California Kid (CK); M. species bovine serogroup 7 strain PG50, and ovine/caprine serogroup 11 strain 2-D. The isolates fell into 5 main groups: (a) 14 serologically homogeneous isolates similar to subsp. mycoides SC PG1, (b) 4 homogeneous isolates similar to PG50, (c) 14 isolates all serologically similar to Y Goat, but heterogeneously reactive with subsp. capri PG3 and M. capricolum CK antisera, (d) 7 isolates serologically similar to subsp. capri PG3, but heterogeneously reactive with subsp. mycoides SC PG1, M. capricolum CK and 2-D antisera and (e) 28 isolates strongly reactive with both M. capricolum CK and serogroup 7 PG50 antisera. 119 isolates that were all glucose and arginine negative were also compared by the MF dot method with the reference strains. Most of these could be classified definitely as M. bovis (78 isolates), M. agalactiae (21 isolates) and serogroup 11 (5 isolates). 13 isolates gave a strong reaction with both M. bovigenitalium and serogroup p11 antisera. Two isolates showed an unclassifiable pattern. It was concluded that the glucose and arginine-negative cluster strains that reacted with 2-D antiserum, also share serological relationships with the "M. mycoides cluster", albeit with a very heterogeneous pattern.