Emydomyces testavorans , a New Genus and Species of Onygenalean Fungus Isolated from Shell Lesions of Freshwater Aquatic Turtles

Abstract

The fungal orderOnygenalesincludes many pathogens of humans and animals, and recent studies have shown some onygenalean fungi to be significant emerging pathogens of reptiles. Although many of these fungi have similar morphological features in histologic tissue sections, recent molecular analyses have revealed a genetically complex and diverse group of reptile pathogens comprising several genera, most notablyNannizziopsis,Ophidiomyces, andParanannizziopsis. Infections by members of these genera have been previously reported in a variety of reptile species, including crocodilians, lizards, snakes, and tuataras, with negative impacts on conservation efforts for some reptiles. Despite the well-documented pathogenicity of these fungi in all other extant reptile lineages, infection has not yet been reported in aquatic turtles. In this study, we report the isolation of an onygenalean fungus associated with shell lesions in freshwater aquatic turtles. The morphologic and genetic characteristics of multiple isolates (n= 21) are described and illustrated. Based on these features and results of a multigene phylogenetic analysis, a new genus and species,Emydomyces testavorans, are proposed for these fungi isolated from turtle shell lesions.

Clinical Manifestation and Molecular Characterization of a Novel Member of the Nannizziopsiaceae in a Pulmonary Granuloma From a Galapagos Tortoise (Chelonoidis nigra)

“…It should be noted that we did not have actin sequence for Paranannizziopsis, so this placement is based solely on ITS2 data. Even with additional gene sequences, strong support for this was not found in some other analyses (21). Use of additional genes would resolve placement of Paranannizziopsis.…”

“…Aphanoascella galapagoensis, a member of the Onygenales in the family Onygenaceae, was isolated from a Galapagos tortoise with carapacial keratitis (3). Recently, Emydomyces testavorans, a member of the Onygenales that does not cluster with the Nannizziopsiaceae, was reported in shell lesions from diverse aquatic turtles (21).…”

Consistent patterns in 16S and 18S microbial diversity from the shells of the common and widespread red-eared slider turtle (Trachemys scripta)

“…Microbial community samples of ca. 50-125 mm 3 were collected from 8 scutes per captured turtle (Fig 1) using a dental calculus scraper sterilized with 70% ethanol prior to collecting each sample. For the two sampled turtles at the "Altus large pond site" (ALP), four samples were collected from carapace scutes only, https://doi.org/10.1371/journal.pone.0244489.g001…”

“…Very generally, the external microbiomes of organisms are influenced by climatic effects, rather than "top-down" or species-specific effects [2]. This suggests that turtles could be susceptible to pathogenic microbial growth on external surfaces, including for novel reptile-associated [3] and known human pathogens [4] present in the environment. Freshwater turtles are also known to utilize a diversity of areas in shallow to medium-depth aquatic habitats, dependent on interactions between and within turtle species, abiotic factors, and disturbance [5][6][7][8][9][10].…”

Plasma complement activation mechanisms differ in ornate (Terrapene ornata ornata) and eastern box turtles (Terrapene carolina carolina)

“…(Farkas & Gal, 2009), despite significant surveillance effort by the authors in free‐living populations. In alligator snapping turtles, morbidity and mortality have been associated with ranavirus (Yu et al, 2015) and Emydomyces testavorans infection (Woodburn et al, 2019). Mycoplasma sp.…”