J.N. Hartfield1, Amy M. Grooters1, Kyle J. Waite1
1Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA
Tóm tắt
BackgroundLagenidium giganteum forma caninum infection causes severe cutaneous and disseminated disease in dogs. Currently, diagnosis requires culture and rRNA gene sequencing.ObjectiveTo develop and evaluate an ELISA for quantitation of anti‐L. giganteum f. caninum IgG in canine serum.AnimalsSera were evaluated from 22 dogs infected with L. giganteum f. caninum, 12 dogs infected with Paralagenidium karlingii, 18 dogs infected with Pythium insidiosum, 26 dogs with nonoomycotic fungal infections or other cutaneous or systemic diseases, and 10 healthy dogs.MethodsAntigen was prepared from a soluble mycelial extract of L. giganteum f. caninum. Optimal antigen and antibody concentrations were determined by checkerboard titration. Results were expressed as percent positivity (PP) relative to a strongly positive control serum.ResultsMedians and ranges for PP for each group were: L. giganteum f. caninum (73.9%, 27.9–108.9%), P. karlingii (55.0%, 21.0–90.6%), P. insidiosum (31.3%, 15.8–87.5%), nonoomycotic fungal infection or other cutaneous or systemic diseases (19.2%, 3.2–61.0%), and healthy dogs (9.9%, 7.6–24.6%). Using a PP cutoff value of 40%, sensitivity and specificity (with 95% CI) of the ELISA for detecting L. giganteum f. caninum infection in clinically affected dogs were 90.9% (72.2–97.5%) and 73.2% (60.4–83.0%), respectively. Specificity in dogs infected with P. karlingii was 41.7% (19.3–68.1%) and with P. insidiosum was 66.7% (43.8–83.7%).Conclusions and Clinical ImportanceQuantitation of anti‐L. giganteum f. caninum antibodies for detection of this infection in dogs has moderately high sensitivity but poor specificity, the latter because of substantial cross‐reactivity with anti‐P. karlingii and anti‐P. insidiosum antibodies.
