2021 Volume 26 Issue 4 Pages 103-111
Paracoccidioidomycosis ceti (PCM-C) is a zoonotic mycosis characterized by chronic granulomatous keloidal dermatitis in cetaceans that has been reported worldwide. The causative agents of PCM-C are unculturable Paracoccidioides brasiliensis var. ceti and Paracoccidioides spp., which are genetically identical to one of the causative agents of paracoccidioidomycosis: P. brasiliensis sensu stricto. The definitive diagnosis of PCM-C is based on clinical symptoms and the detection of yeast-like cells during pathological examinations; molecular diagnosis is not essential. However, analyses at the molecular level are important to distinguish PCM-C from other fungal infections showing similar clinical signs. Researchers have been following a suspected case of PCM-C in a Pacific white-sided dolphin (Lagenorhynchus obliquidens) by performing cytology, histopathology, and molecular biology experiments since 2015. Finally, we confirmed it as the fourth Japanese PCM-C case based on the partial sequence of 43-kDa glycoprotein antigen gene (gp43) with 99.4% identity to that from P. brasiliensis sensu stricto from a biopsied sample in October 2019. Then, we applied a loop-mediated isothermal amplification (LAMP) for P. brasiliensis. The simple LAMP targeting for fungal DNA and human clinical materials failed to amplify bands, but a combination of polymerase chain reaction (PCR) and LAMP (PCR-LAMP) could amplify species-specific ladder-like bands identical to P. brasiliensis.