RESUMO
Paracoccidioidomycosis ceti (PCM-C) is a chronic granulomatous keloidal dermatitis in cetaceans that has been reported worldwide and is caused by Paracoccidioides ceti. Serological cross-reactions among highly pathogenic fungal infections and related diseases have been reported. However, the true cross-reaction of antibodies against P. ceti has remained unknown due to the use of positive control sera from infected dolphins. This study aimed to re-evaluate antibodies from mechanically dislodged fungal cells in the infected tissue of a PCM-C case and demonstrate the actual cross-reaction. The results revealed a limited cross-reaction between PCM-C and paracoccidioidomycosis, while the antibodies did not react with other pathogens such as Coccidioides posadasii, Histoplasama capsulatum, and Arthrographis kalrae. Thus, the method for evaluation of the antibody against PCM-C is reliable, and there is potential for epidemiological study.
RESUMO
Paracoccidiodomycosis ceti (PCM-C) is a zoonotic mycosis characterized by chronic granulomatous cutaneous lesions in cetaceans. It is distributed worldwide and is caused by an unculturable fungus; Paracoccidioides cetii. On the other hand, coccidioidomycosis (CCM), caused by Coccidioides spp., is also a zoonotic and highly pathogenic fungal infection endemic in both American continents. Even though the Far East is not an endemic area of CCM, an autochthonous case has been reported in China. Although the seroprevalence against P. cetii in captive dolphins was 61.0%, there is no information on wild dolphins living in cold waters. The present study aimed to investigate the seroprevalence against P. cetii and C. posadasii in 15 Dall's porpoises (Phocoenoides dalli) and 11 harbor porpoises (Phocoena phocoena) stranded in Hokkaido, Japan. The seroprevalence against P. cetii in the above dolphins was 26.9% (7/26), which was recorded only in Dall's porpoises (7/15), and that against C. posadasii was 15.4% (4/26), three in Dall's porpoises and one in harbor porpoise. The present study demonstrated positive seroprevalence against P. cetii and C. posadasii in wild cetaceans living in the subarctic areas of the Far East as the first records, and would issue the warning those who live in the area were exposed to the causative agent of CCM from seawater.
Assuntos
Coccidioidomicose , Golfinhos , Paracoccidioides , Phocoena , Animais , Coccidioides , Japão , Estudos SoroepidemiológicosRESUMO
The prominence of seafood in Japan motivates close monitoring of its seas and marine lives for potentially pathogenic fungi. During the treatments of the male Pacific white-sided dolphin (Lagenorhynchus obliquidens) for paracoccidioidomycosis ceti (PCM-C), 5 white and floccose colonies showing identical genotype and morphological characteristics were isolated from two skin biopsy samples of cutaneous granulomatous lesions in 2018. The isolates were identified as Parengyodontium album known as one of fungal species having abilities to produce industrially important proteases, and to become a causative agent for emerging mycosis based on morphological and molecular biological characteristics. These lesions consisted of non-malignant pearl-like structures of hyperplastic keratinocytes. Interestingly, although the isolates could grow at 35 °C, their DNA sequences were phylogenetically located in a cluster consisting of environmental and clinical isolates lacking the ability to grow at 35 °C, based on previous reports. The opportunistic infection we observed in the dolphin might be caused by immune disorder due to PCM-C. Notably, although P. album is recognized as non-harmful, and has significant industrial importance and antitumor activity, it has potential to cause not only superficial but also systemic infection, and presents difficulties in treatment because of its high resistance to antifungal compounds.