Blastomyces dermatitidisYeast Lysate Antigen Combinations: Antibody Detection in Dogs with Blastomycosis

Abstract

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.

<i>Blastomyces dermatitidis</i> Antibody Responses in Serial Serum Specimens from Dogs with Blastomycosis: Comparison of Different Yeast Lysate Antigens

“…The T-58 yeast phase lysate antigen prepared from a Tennessee dog isolate was optimal with respect to detecting antibody in the dog sera from Tennessee using the indirect ELISA (52 of the 55 sera with absorbance values greater than the critical absorbance value of 0.360). Previous studies using the T-58 lysate antigen to detect antibody in sera in dogs from Minnesota or Wisconsin showed similar reactivity patterns as shown above [14] [16] [17] [19]. The origin of the serum does not influence the reactivity of the lysate antigens.…”

“…Due to the increase in systemic fungal diseases researchers have begun to devote more attention to the development of immunodiagnostic assays that are reliable for blastomycosis [6] [7] [10]- [12]. For several years the thrust of research in our laboratory has also been associated with the production and comparative studies of B. dermatitidis yeast lysate antigens, prepared from various isolates of the fungus for the detection of antibodies in sera from immunized and infected animals [13]- [19]. Encouraging results have been obtained with novel yeast lysate antigenic preparations.…”