The systemic
fungal infection,
blastomycosis, which infects both humans and animals has presented a diagnostic challenge for clinicians for many years. The aim of this study was to evaluate the diagnostic sensitivity of Blastomyces dermatitidis yeast lysate
antigens with respect to antibody detection in dogs with
blastomycosis. Lysate
antigens were prepared from B. dermatitidis isolates T-58 and
T-66 (dogs, Tennessee) and WI-R and WI-J (dogs, Wisconsin). Based on results obtained from a preliminary comparative study, five combinations of these isolates and one individual isolate were tested against 92 serum specimens from dogs with culture-proven or histologically-confirmed
blastomycosis, using the indirect
enzyme-linked
immunosorbent assay (ELISA). Mean absorbance values obtained from the sera ranged from 0.905 with the individual T-58
antigen to 1.760 using an
antigen combination (T-58 +
T-66 + WI-R). All of the 6 antigenic preparations were able to detect antibody in the serum specimens, but the
antigen combinations detected antibody to a higher degree than the individual
antigen. This study provides evidence that combinations of the yeast lysate
reagents seem to be more efficacious for antibody detection in dog sera, but our laboratory is continuing to evaluate
antigen lysate combinations for detection of
antibodies in
blastomycosis.