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Borteiro C, Laufer G, Gobel N, Arleo M, Kolenc F, Cortizas S, Barrasso DA, de Sá RO, Soutullo A, Ubilla M, Martínez-Debat C. Widespread occurrence of the amphibian chytrid panzootic lineage in Uruguay is constrained by climate. DISEASES OF AQUATIC ORGANISMS 2024; 158:123-132. [PMID: 38813853 DOI: 10.3354/dao03783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) causes chytridiomycosis, a disease among the main causes of amphibian declines worldwide. However, Bd studies on Neotropical amphibians from temperate areas are scarce. We present a comprehensive survey of Bd in Uruguay, in temperate central eastern South America, carried out between 2006 and 2014. Skin swabs of 535 specimens of 21 native and exotic frogs were tested by PCR. We used individual-level data to examine the relationship between infection, climatic variables, and their effects on body condition and the number of prey items found in stomach contents. Infection was widespread in free-ranging anurans with an overall prevalence of 41.9%, detected in 15 native species, wild American bullfrogs Aquarana catesbeiana, and captive specimens of Ceratophrys ornata and Xenopus laevis. Three haplotypes of the Bd ITS region were identified in native amphibians, all belonging to the global panzootic lineage (BdGPL), of which only one was present in exotic hosts. Despite high infection frequencies in different anurans, we found no evidence of morbidity or mortality attributable to chytridiomycosis, and we observed no discernible impact on body condition or consumed prey. Climatic conditions at the time of our surveys suggested that the chance of infection is associated with monthly mean temperature, mean humidity, and total precipitation. Temperatures below 21°C combined with moderate humidity and pronounced rainfall may increase the likelihood of infection. Multiple haplotypes of BdGPL combined with high frequencies of infection suggest an enzootic pattern in native species, underscoring the need for continued monitoring.
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Affiliation(s)
- Claudio Borteiro
- Sección Herpetología, Museo Nacional de Historia Natural, Montevideo 11800, Uruguay
| | - Gabriel Laufer
- Área Biodiversidad y Conservación, Museo Nacional de Historia Natural, Montevideo 11800, Uruguay
- Vida Silvestre Uruguay, Montevideo 11100, Uruguay
| | - Noelia Gobel
- Área Biodiversidad y Conservación, Museo Nacional de Historia Natural, Montevideo 11800, Uruguay
- Vida Silvestre Uruguay, Montevideo 11100, Uruguay
| | - Mailén Arleo
- Sección Bioquímica, Departamento de Biología, Facultad de Ciencias, Universidad de la República, Montevideo 11400, Uruguay
| | - Francisco Kolenc
- Sección Herpetología, Museo Nacional de Historia Natural, Montevideo 11800, Uruguay
| | - Sofía Cortizas
- Grupo de Agroecología, Sustentabilidad y Medio Ambiente, Universidad Tecnológica del Uruguay, Durazno 97000, Uruguay
| | - Diego A Barrasso
- Instituto de Diversidad y Evolución Austral (IDEAus-CONICET), and Facultad de Ciencias Naturales y Ciencias de la Salud, Universidad Nacional de la Patagonia 'San Juan Bosco' (UNPSJB), Puerto Madryn 9120, Chubut, Argentina
| | - Rafael O de Sá
- Department of Biology, University of Richmond, Richmond, Virginia 23173, USA
| | - Alvaro Soutullo
- Departamento de Ecología y Gestión Ambiental, Centro Universitario Regional del Este, Punta del Este 20100, Universidad de la República, Uruguay
| | - Martin Ubilla
- Departamento de Paleontología-ICG, Facultad de Ciencias, Universidad de la República, Montevideo 11400, Uruguay
| | - Claudio Martínez-Debat
- Sección Bioquímica, Departamento de Biología, Facultad de Ciencias, Universidad de la República, Montevideo 11400, Uruguay
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Schilliger L, Paillusseau C, François C, Bonwitt J. Major Emerging Fungal Diseases of Reptiles and Amphibians. Pathogens 2023; 12:pathogens12030429. [PMID: 36986351 PMCID: PMC10053826 DOI: 10.3390/pathogens12030429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/16/2023] [Accepted: 03/06/2023] [Indexed: 03/11/2023] Open
Abstract
Emerging infectious diseases (EIDs) are caused by pathogens that have undergone recent changes in terms of geographic spread, increasing incidence, or expanding host range. In this narrative review, we describe three important fungal EIDs with keratin trophism that are relevant to reptile and amphibian conservation and veterinary practice. Nannizziopsis spp. have been mainly described in saurians; infection results in thickened, discolored skin crusting, with eventual progression to deep tissues. Previously only reported in captive populations, it was first described in wild animals in Australia in 2020. Ophidiomyces ophidiicola (formely O. ophiodiicola) is only known to infect snakes; clinical signs include ulcerating lesions in the cranial, ventral, and pericloacal regions. It has been associated with mortality events in wild populations in North America. Batrachochytrium spp. cause ulceration, hyperkeratosis, and erythema in amphibians. They are a major cause of catastrophic amphibian declines worldwide. In general, infection and clinical course are determined by host-related characteristics (e.g., nutritional, metabolic, and immune status), pathogens (e.g., virulence and environmental survival), and environment (e.g., temperature, hygrometry, and water quality). The animal trade is thought to be an important cause of worldwide spread, with global modifications in temperature, hygrometry, and water quality further affecting fungal pathogenicity and host immune response.
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Affiliation(s)
- Lionel Schilliger
- Argos Veterinary Clinic of Paris Auteuil, 35 Rue Leconte de Lisle, 75016 Paris, France
- SpéNac Referral Center, 100 Boulevard de la Tour Maubourg, 75007 Paris, France
- Correspondence: ; Tel.: +33-188-616-831
| | - Clément Paillusseau
- Argos Veterinary Clinic of Paris Auteuil, 35 Rue Leconte de Lisle, 75016 Paris, France
- SpéNac Referral Center, 100 Boulevard de la Tour Maubourg, 75007 Paris, France
| | - Camille François
- Argos Veterinary Clinic of Paris Auteuil, 35 Rue Leconte de Lisle, 75016 Paris, France
- SpéNac Referral Center, 100 Boulevard de la Tour Maubourg, 75007 Paris, France
| | - Jesse Bonwitt
- Department of Anthropology, Durham University, South Rd., Durham DH1 3LE, UK
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Abstract
This article updates the understanding of two extirpation-driving infectious diseases, Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans, and Ranavirus. Experimental studies and dynamic, multifactorial population modeling have outlined the epidemiology and future population impacts of B dendrobatidis, B salamandrivorans, and Ranavirus. New genomic findings on divergent fungal and viral pathogens can help optimize control and disease management strategies. Although there have been major advances in knowledge of amphibian pathogens, controlled studies are needed to guide population recovery to elucidate and evaluate transmission routes for several pathogens, examine environmental control, and validate new diagnostic tools to confirm the presence of disease.
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