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Mathur S, Haynes E, Allender MC, Gibbs HL. Genetic mechanisms and biological processes underlying host response to ophidiomycosis (snake fungal disease) inferred from tissue-specific transcriptome analyses. Mol Ecol 2024; 33:e17210. [PMID: 38010927 DOI: 10.1111/mec.17210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 07/28/2023] [Accepted: 11/06/2023] [Indexed: 11/29/2023]
Abstract
Emerging infectious diseases in wildlife species caused by pathogenic fungi are of growing concern, yet crucial knowledge gaps remain for diseases with potentially large impacts. For example, there is detailed knowledge about host pathology and mechanisms underlying response for chytridiomycosis in amphibians and white-nose syndrome in bats, but such information is lacking for other more recently described fungal infections. One such disease is ophidiomycosis, caused by the fungus Ophidiomyces ophidiicola, which has been identified in many species of snakes, yet the biological mechanisms and molecular changes occurring during infection are unknown. To gain this information, we performed a controlled experimental infection in captive Prairie rattlesnakes (Crotalus viridis) with O. ophidiicola at two different temperatures: 20 and 26°C. We then compared liver, kidney, and skin transcriptomes to assess tissue-specific genetic responses to O. ophidiicola infection. Given previous histopathological studies and the fact that snakes are ectotherms, we expected highest fungal activity on skin and a significant impact of temperature on host response. Although we found fungal activity to be localized on skin, most of the differential gene expression occurred in internal tissues. Infected snakes at the lower temperature had the highest host mortality whereas two-thirds of the infected snakes at the higher temperature survived. Our results suggest that ophidiomycosis is likely a systemic disease with long-term effects on host response. Our analysis also identified candidate protein coding genes that are potentially involved in host response, providing genetic tools for studies of host response to ophidiomycosis in natural populations.
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Affiliation(s)
- Samarth Mathur
- Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Columbus, Ohio, USA
- Ohio Biodiversity Conservation Partnership, The Ohio State University, Columbus, Ohio, USA
| | - Ellen Haynes
- Wildlife Epidemiology Laboratory, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Southeastern Cooperative Wildlife Disease Study, University of Georgia, Athens, Georgia, USA
| | - Matthew C Allender
- Wildlife Epidemiology Laboratory, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Brookfield Zoo, Chicago Zoological Society, Brookfield, Illinois, USA
| | - H Lisle Gibbs
- Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Columbus, Ohio, USA
- Ohio Biodiversity Conservation Partnership, The Ohio State University, Columbus, Ohio, USA
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Kendall MW, Wright AD, Adamovicz LA, Durante K, Andersson KE, Frederickson K, Vivirito K, Ospina EA, Delaney MA, Allender MC. Environmental temperature influences ophidiomycosis progression and survival in experimentally challenged prairie rattlesnakes (Crotalus viridis). PLoS One 2023; 18:e0289641. [PMID: 37535551 PMCID: PMC10399908 DOI: 10.1371/journal.pone.0289641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 07/21/2023] [Indexed: 08/05/2023] Open
Abstract
Ophidiomycosis is a prevalent and intermittently pervasive disease of snakes globally caused by the opportunistic fungal pathogen, Ophidiomyces ophidiicola. Host response has yet to be fully explored, including the role of temperature in disease progression and hematologic changes. This study enrolled twelve adult prairie rattlesnakes (Crotalus viridis) in an experimental challenge with O. ophidiicola at two temperatures, 26°C (n = 6) and 20°C (n = 6). Each temperature cohort included four inoculated and two control snakes. Assessments involving physical exams, lesion swabbing, and hematology were performed weekly. Differences were observed between inoculated and control snakes in survival, behavior, clinical signs, ultraviolet (UV) fluorescence, hematologic response, and histologic lesions. All inoculated snakes held at 20°C were euthanized prior to study end date due to severity of clinical signs while only one inoculated animal in the 26°C trial met this outcome. In both groups, qPCR positive detection preceded clinical signs with regards to days post inoculation (dpi). However, the earliest appearance of gross lesions occurred later in the 20°C snakes (20 dpi) than the 26°C snakes (13 dpi). Relative leukocytosis was observed in all inoculated snakes and driven by heterophilia in the 20°C snakes, and azurophilia in the 26°C group. Histologically, 20°C snakes had more severe lesions, a lack of appropriate inflammatory response, and unencumbered fungal proliferation and invasion. In contrast, 26°C snakes had marked granulomatous inflammation with encapsulation of fungi and less invasion and dissemination. The results of this study identified that O. ophidiicola-infected rattlesnakes exposed to lower temperatures have decreased survival and more robust hematologic change, though minimal and ineffective inflammatory response at site of infection. Ophidiomycosis is a complex disease with host, pathogen, and environmental factors influencing disease presentation, progression, and ultimately, survival. This study highlighted the importance of temperature as an element impacting the host response to O. ophidiicola.
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Affiliation(s)
- Michelle Waligora Kendall
- Wildlife Epidemiology Lab, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, United States of America
| | - Allison D Wright
- Wildlife Epidemiology Lab, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, United States of America
| | - Laura A Adamovicz
- Wildlife Epidemiology Lab, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, United States of America
- The Veterinary Diagnostic Laboratory, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, United States of America
| | - Kennymac Durante
- Wildlife Epidemiology Lab, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, United States of America
| | - Kirsten E Andersson
- Wildlife Epidemiology Lab, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, United States of America
| | - Kelcie Frederickson
- Wildlife Epidemiology Lab, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, United States of America
| | - Katie Vivirito
- Wildlife Epidemiology Lab, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, United States of America
| | - Emilie A Ospina
- Wildlife Epidemiology Lab, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, United States of America
- The Veterinary Diagnostic Laboratory, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, United States of America
| | - Martha A Delaney
- Zoological Pathology Program, University of Illinois, Brookfield, IL, United States of America
| | - Matthew C Allender
- Wildlife Epidemiology Lab, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, United States of America
- The Veterinary Diagnostic Laboratory, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, United States of America
- The Brookfield Zoo, Chicago Zoological Society, Brookfield, Illinois, United States of America
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Lind CM, Agugliaro J, Lorch JM, Farrell TM. Ophidiomycosis is related to seasonal patterns of reproduction, ecdysis, and thermoregulatory behavior in a free‐living snake species. J Zool (1987) 2022. [DOI: 10.1111/jzo.13024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
| | | | - J. M. Lorch
- U.S. Geological Survey ‐ National Wildlife Health Center Madison WI USA
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