Ochroconis globalis infecting Atlantic salmon (Salmo salar), with a review of Ochroconis species in cold‐blooded animals

Abstract

Necropsy examination of an adult Atlantic salmon (Salmo salar) from the Dalälven River in Sweden revealed numerous large, white nodules, with spherical cysts and granulomata in kidney and liver. Histopathology showed dark, septate, thin‐walled hyphae. The aetiologic agent was found to be an Ochroconis species (Venturiales) that differed from known fish‐associated species of the genus. Molecular phylogenetic studies of the culture (strain UIII09 = CBS 135766) demonstrated that Ochroconis globalis was concerned. The isolate proved to be susceptible to all investigated antifungals, as it is known for another Ochroconis species. The role of Ochroconis in opportunism of cold‐blooded animals was discussed, and the diagnostic methods using DNA sequences for routine identification of the fungus were proposed.

Retrospective study of phaeohyphomycosis in aquarium‐housed fish, with first descriptions of Exophiala lecanii‐corni and Neodevriesia cladophorae in fish

“…However, these species remain differential considerations as not all submissions, including the affected seadragon, were cultured (Nyaoke et al, 2009). The genus Ochroconis contains numerous waterborne species pathogenic in poikilothermic vertebrates (Samerpitak et al, 2019;Schaumann & Priebe, 1994;Seyedmousavi et al, 2013 Schaumann & Priebe, 1994;Seyedmousavi et al, 2013;Tarrand et al, 2003;Wada et al, ,1995Wada et al, , , 2005. The two cases included here involved perciform marine fish, both with splenic lesions and additional renal and swim bladder lesions in one.…”

“…Three species, Ochroconis globalis, O . humicola and O. tshawytschae , are implicated in fish disease, primarily affecting intensive aquaculture operations producing various salmonids, devil stingers ( Inimicus japonicus ), red seabream ( Pagrus major ), striped jack ( Pseudocaranx dentex) and marbled rockfish ( Sebastiscus marmoratus ) (Doty & Slater, 1946; Munchan, 2006; Samerpitak et al., ,2014, 2019; Schaumann & Priebe, 1994; Seyedmousavi et al., 2013; Tarrand et al., 2003; Wada et al., ,1995, 2005). The two cases included here involved perciform marine fish, both with splenic lesions and additional renal and swim bladder lesions in one.…”

“…The genus Ochroconis contains numerous waterborne species pathogenic in poikilothermic vertebrates (Samerpitak et al., 2019; Schaumann & Priebe, 1994; Seyedmousavi et al., 2013). Three species, Ochroconis globalis, O .…”

“…The two cases included here involved perciform marine fish, both with splenic lesions and additional renal and swim bladder lesions in one. Optimal growth temperature ranges for most Ochroconis species are 21–27°C, typical of many aquarium habitats (Samerpitak et al., 2019).…”