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Ash LV, Campião KM, Teixeira CP, Gotelli NJ. Ranavirus and helminth parasite co-infection in invasive American bullfrogs in the Atlantic forest, Brazil. Int J Parasitol Parasites Wildl 2024; 23:100924. [PMID: 38586581 PMCID: PMC10997893 DOI: 10.1016/j.ijppaw.2024.100924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 03/10/2024] [Accepted: 03/10/2024] [Indexed: 04/09/2024]
Abstract
Emerging infectious diseases threaten amphibian species across the globe. In Brazil, the American bullfrog (Aquarana catesbeiana) is a highly invasive species that can potentially transmit parasites and pathogens to native amphibians. This is the first assessment of co-infection of Ranavirus and helminth macroparasites in invasive populations of bullfrogs in South America. We collected, measured, and euthanized 65 specimens of A. catesbeiana sampled from 9 sites across three states of Brazil in the Atlantic Forest biome. We collected and identified helminth macroparasites and sampled host liver tissue to test for the presence and load of Ranavirus with quantitative PCR. We documented patterns of prevalence, parasite load, and co-infection with generalized linear mixed models, generalized logistic regressions, and randomization tests. Most individual bullfrogs did not exhibit clinical signs of infection, but the overall Ranavirus prevalence was 27% (95% confidence interval, [CI 17-38]). Bullfrogs were infected with helminth macroparasites from 5 taxa. Co-infection of helminth macroparasites and Ranavirus was also common (21% CI [12-31]). Bullfrog size was positively correlated with total macroparasite abundance and richness, and the best-fitting model included a significant interaction between bullfrog size and Ranavirus infection status. We observed a negative correlation between Ranavirus viral load and nematode abundance (slope = -0.22, P = 0.03). Invasive bullfrogs (A. catesbeiana) in Brazil were frequently infected with both Ranavirus and helminth macroparasites, so adult bullfrogs could serve as reservoir hosts for both pathogens and parasites. However, many macroparasites collected were encysted and not developing. Coinfection patterns suggest a potential interaction between Ranavirus and macroparasites because helminth abundance increased with bullfrog size but was lower in Ranavirus infected individuals. Future studies of bullfrogs in the Atlantic Forest should investigate their potential role in pathogen and parasite transmission to native anurans.
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Affiliation(s)
- Lauren V. Ash
- University of Vermont, Department of Biology, 109 Carrigan Drive, Burlington, VT, 05403, USA
| | - Karla Magalhães Campião
- Laboratório de Interações Biológicas, Departamento de Zoologia, Universidade Federal do Paraná, UFPR, Curitiba, Paraná, Brazil
| | - Cauê Pinheiro Teixeira
- Laboratório de Interações Biológicas, Departamento de Zoologia, Universidade Federal do Paraná, UFPR, Curitiba, Paraná, Brazil
| | - Nicholas J. Gotelli
- University of Vermont, Department of Biology, 109 Carrigan Drive, Burlington, VT, 05403, USA
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Falconnier N, Warshaw M, Wellehan JFX, Childress AL, Howe DK, Taylor H, Langohr IM, Ard MB, Paulsen DB, Sasaki E, Mitchell MS, Carossino M. Systemic Caryospora-like coccidiosis in a clutch of hatchling red-eared slider turtles ( Trachemys scripta elegans). Vet Pathol 2024; 61:95-108. [PMID: 37306029 DOI: 10.1177/03009858231179129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Caryospora-like organisms (CLOs) form a clade of at least 11 genotypes of related coccidia that can cause epizootic mortality in marine turtles. The biology, transmission, host species range, and host cell tropism of these organisms are still largely unknown. The goal of this study was to characterize the host cell tropism, pathologic and ultrastructural features, and phylogeny associated with the first report of a mortality event due to CLO in the freshwater red-eared slider turtle (Trachemys scripta elegans). Sudden mortalities within a clutch of captive-raised red-eared slider hatchlings (n = 8) were recorded, and deceased animals had severe segmental to diffuse, transmural, fibrinonecrotic enterocolitis and multifocal to coalescing hepatic necrosis, among other lesions associated with numerous intracytoplasmic developing stages of intralesional coccidia. Among the different developmental stages, merozoites were ultrastructurally characterized by an apical complex. A pan-apicomplexan polymerase chain reaction (PCR) yielded a 347 bp-amplicon matching the Schellackia/Caryospora-like clade with 99.1% identity to the US3 strain from green sea turtles (Chelonia mydas) and 99.1% identity to Schellackia sp. Isolate OC116. Surviving hatchlings were treated with toltrazuril sulfone (ponazuril) but were subsequently euthanized due to the risk of spreading the parasite to other chelonids in the collection. The ponazuril-treated hatchlings (n = 4) had mild proliferative anterior enteritis, with few intraepithelial coccidia in one hatchling confirmed as CLO by PCR. This is the first report of Caryospora-like coccidiosis in non-cheloniid turtles, highlighting the relevance of this disease as an emerging highly pathogenic intestinal and extra-intestinal form of coccidiosis of turtles with potential cross-species infectivity.
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Affiliation(s)
| | - Michael Warshaw
- Baton Rouge Zoo, Baton Rouge, LA
- Saint Louis Zoo, St. Louis, MO
| | | | | | | | | | | | | | | | - Emi Sasaki
- Louisiana State University, Baton Rouge, LA
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Vincent LM, Allender MC, Curtis AE, Madden NE, Cray C, Lance S, McFall A, Adamovicz L. CUTANEOUS MYIASIS AND ITS RELATIONSHIP TO WELLNESS IN EASTERN BOX TURTLES ( TERRAPENE CAROLINA CAROLINA) IN CAPE COD, MASSACHUSETTS. J Zoo Wildl Med 2024; 54:785-795. [PMID: 38252002 DOI: 10.1638/2022-0173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2023] [Indexed: 01/23/2024] Open
Abstract
Eastern box turtles (Terrapene carolina carolina) face a variety of anthropogenic, infectious, and environmental threats and have been affected by high morbidity and mortality disease events. Wellness parameters in free-ranging eastern box turtles with a high prevalence of myiasis on Cape Cod, MA, were documented to identify epidemiologic trends or associations with several health parameters. There were 109 samples collected from 59 individual box turtles over the course of 4 mon. Six turtles died over the course of this study. Fly larvae infestations varied in severity and were observed in the cutaneous and subcutaneous tissue (n = 18; 30.5%). Animals with myiasis had fewer plastron abnormalities than those without (P = 0.034), and all turtles found in bogs had evidence of fly larvae infections (P < 0.0001). Individuals with myiasis also had lower body condition index (P = 0.014), lower total white blood cells (P = 0.031), lower PCV (P < 0.0001), lower total solids (P < 0.0001), higher erythrocyte sedimentation rate (P < 0.0001), lower calcium (P = 0.018), and lower phosphorus (P = 0.017). Three turtles tested positive for terrapene herpesvirus 1, but presence was not associated with myiasis. Heavy metal analysis revealed no significant differences between turtles with and without myiasis. This study examined the health of a population of eastern box turtles, and continued health assessments will be beneficial in determining the impact of myiasis on future conservation plans.
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Affiliation(s)
- Lauren M Vincent
- Wildlife Epidemiology Laboratory, College of Veterinary Medicine, University of Illinois, IL 61802, USA,
| | - Matthew C Allender
- Wildlife Epidemiology Laboratory, College of Veterinary Medicine, University of Illinois, IL 61802, USA
- Veterinary Diagnostic Laboratory, College of Veterinary Medicine, University of Illinois, IL 61802, USA
- Chicago Zoological Society, Brookfield Zoo, Brookfield, IL 60513, USA
| | - Annie E Curtis
- Natural Resources and Integrated Training Area Management Office, Massachusetts Army National Guard, MA 02542, USA
| | - Nicole E Madden
- Natural Resources and Integrated Training Area Management Office, Massachusetts Army National Guard, MA 02542, USA
| | - Carolyn Cray
- Comparative Pathology Laboratory, University of Miami Miller School of Medicine, FL 33136, USA
| | - Stacey Lance
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802, USA
| | - Adam McFall
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802, USA
| | - Laura Adamovicz
- Wildlife Epidemiology Laboratory, College of Veterinary Medicine, University of Illinois, IL 61802, USA
- Veterinary Diagnostic Laboratory, College of Veterinary Medicine, University of Illinois, IL 61802, USA
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Dallas JW, Warne RW. Ranavirus infection does not reduce heat tolerance in a larval amphibian. J Therm Biol 2023; 114:103584. [PMID: 37209633 DOI: 10.1016/j.jtherbio.2023.103584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 04/24/2023] [Accepted: 04/27/2023] [Indexed: 05/22/2023]
Abstract
Extreme heat events and emerging infectious diseases negatively impact wildlife populations, but the interacting effects of infection and host heat tolerance remain understudied. The few studies covering this subject have demonstrated that pathogens lower the heat tolerance of their hosts, which places infected hosts at a greater risk experiencing lethal heat stress. Here, we studied how ranavirus infection influenced heat tolerance in larval wood frogs (Lithobates sylvaticus). In line with similar studies, we predicted the elevated costs of ranavirus infection would lower heat tolerance, measured as critical thermal maximum (CTmax), compared to uninfected controls. Ranavirus infection did not reduce CTmax and there was a positive relationship between CTmax and viral loads. Our results demonstrate that ranavirus-infected wood frog larvae had no loss in heat tolerance compared to uninfected larvae, even at viral loads associated with high mortality rates, which contradicts the common pattern for other pathogenic infections in ectotherms. Larval anurans may prioritize maintenance of their CTmax when infected with ranavirus to promote selection of warmer temperatures during behavioral fever that can improve pathogen clearance. Our study represents the first to examine the effect of ranavirus infection on host heat tolerance, and because no decline in CTmax was observed, this suggests that infected hosts would not be under greater risk of heat stress.
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Affiliation(s)
- Jason W Dallas
- School of Biological Sciences, Southern Illinois University Carbondale, 1125 Lincoln Street, Carbondale, IL, 62901, USA.
| | - Robin W Warne
- School of Biological Sciences, Southern Illinois University Carbondale, 1125 Lincoln Street, Carbondale, IL, 62901, USA
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Koda SA, Subramaniam K, Hick PM, Hall E, Waltzek TB, Becker JA. Partial validation of a TaqMan quantitative polymerase chain reaction for the detection of the three genotypes of Infectious spleen and kidney necrosis virus. PLoS One 2023; 18:e0281292. [PMID: 36735738 PMCID: PMC9897559 DOI: 10.1371/journal.pone.0281292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 01/19/2023] [Indexed: 02/04/2023] Open
Abstract
Megalocytiviruses (MCVs) are double-stranded DNA viruses known to infect important freshwater and marine fish species in the aquaculture, food, and ornamental fish industries worldwide. Infectious spleen and kidney necrosis virus (ISKNV) is the type species within the genus Megalocytivirus that causes red seabream iridoviral disease (RSIVD) which is a reportable disease to the World Animal Health Organization (WOAH). To better control the transboundary spread of this virus and support WOAH reporting requirements, we developed and partially validated a TaqMan real-time qPCR assay (ISKNV104R) to detect all three genotypes of ISKNV, including the two genotypes that cause RSIVD. Parameters averaged across 48 experiments used a 10-fold dilution series of linearized plasmid DNA (107-101 copies), carrying a fragment of the three-spot gourami iridovirus (TSGIV) hypothetical protein revealed that the assay was linear over 7 orders of magnitude (107-101), a mean efficiency of 99.97 ± 2.92%, a mean correlation coefficient of 1.000 ± 0.001, and a limit of detection (analytical sensitivity) of ≤10 copies of TSGIV DNA. The diagnostic sensitivity and specificity for the ISKNV104R qPCR assay was evaluated and compared to other published assays using a panel of 397 samples from 21 source populations with different prevalence of ISKNV infection (0-100%). The diagnostic sensitivity and specificity for the ISKNV104R qPCR assay was 91.99% (87.28-95.6; 95% CI) and 89.8% (83.53-94.84). The latent class analysis showed that the ISKNV104R qPCR assay had similar diagnostic sensitivities and specificities with overlapping confidence limits compared to a second TaqMan qPCR assay and a SYBR green assay. This newly developed TaqMan assay represents a partially validated qPCR assay for the detection of the three genotypes of the species ISKNV. The ISKNV104R qPCR assay once fully validated, will serve as an improved diagnostic tool that can be used for ISKNV surveillance efforts and diagnosis in subclinical fish to prevent further spread of MCVs throughout the aquaculture and ornamental fish industries.
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Affiliation(s)
- Samantha A. Koda
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
| | - Kuttichantran Subramaniam
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
| | - Paul M. Hick
- Sydney School of Veterinary Science, The University of Sydney, Camden, New South Wales, Australia
| | - Evelyn Hall
- Sydney School of Veterinary Science, The University of Sydney, Camden, New South Wales, Australia
| | - Thomas B. Waltzek
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
- * E-mail: (JAB); (TBW)
| | - Joy A. Becker
- School of Life and Environmental Sciences, The University of Sydney, Camden, New South Wales, Australia
- * E-mail: (JAB); (TBW)
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Megarani DV, Al-Hussinee L, Subramaniam K, Sriwanayos P, Imnoi K, Keleher B, Nicholson P, Surachetpong W, Tattiyapong P, Hick P, Gustafson LL, Waltzek TB. Development of a TaqMan quantitative reverse transcription PCR assay to detect tilapia lake virus. DISEASES OF AQUATIC ORGANISMS 2022; 152:147-158. [PMID: 36546687 DOI: 10.3354/dao03700] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Tilapia lake virus disease (TiLVD) is an emerging viral disease associated with high morbidity and mortality in cultured tilapia worldwide. In this study, we have developed and validated a TaqMan quantitative reverse transcription PCR (RT-qPCR) assay for TiLV, targeting a conserved region within segment 10 of the genome. The RT-qPCR assay was efficient (mean ± SD: 96.71 ± 3.20%), sensitive with a limit of detection of 10 RNA viral copies per reaction, and detected TiLV strains from different geographic regions including North America, South America, Africa, and Asia. The intra- and inter-assay variability ranged over 0.18-1.41% and 0.21-2.21%, respectively. The TaqMan RT-qPCR assay did not cross-react with other RNA viruses of fish, including an orthomyxovirus, a betanodavirus, a picornavirus, and a rhabdovirus. Analysis of 91 proven-positive and 185 proven-negative samples yielded a diagnostic sensitivity of 96.7% and a diagnostic specificity of 100%. The TaqMan RT-qPCR assay also detected TiLV RNA in infected Nile tilapia liver tissue extracts following an experimental challenge study, and it successfully detected TiLV RNA in SSN-1 (E-11 clone) cell cultures displaying cytopathic effects following their inoculation with TiLV-infected tissue homogenates. Thus, the validated TaqMan RT-qPCR assay should be useful for both research and diagnostic purposes. Additionally, the TiLV qPCR assay returns the clinically relevant viral load of a sample which can assist health professionals in determining the role of TiLV during disease investigations. This RT-qPCR assay could be integrated into surveillance programs aimed at mitigating the effects of TiLVD on global tilapia production.
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Affiliation(s)
- Dorothea V Megarani
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida 32610, USA
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7
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Strachinis I, Marschang RE, Lymberakis P, Karagianni KM, Azmanis P. Infectious disease threats to amphibians in Greece: new localities positive for Batrachochytrium dendrobatidis. DISEASES OF AQUATIC ORGANISMS 2022; 152:127-138. [PMID: 36519684 DOI: 10.3354/dao03712] [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: 06/17/2023]
Abstract
In the early 2000s, numerous cases of European amphibian population declines and mass die-offs started to emerge. Investigating those events led to the discovery that wild European amphibians were confronted with grave disease threats caused by introduced pathogens, namely the amphibian and the salamander chytrid fungi Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal) and ranaviruses. In Greece, Bd was previously documented among wild amphibian populations in 2 different locations and 3 different species. However, no disease-related mass declines or mortality events have been reported. In this work, we build upon previous findings with new, subsequently obtained data, resulting in a 225-sample dataset of 14 species from 17 different locations throughout Greece, in order to examine the occurrence status of all 3 pathogens responsible for emerging infectious diseases in European amphibians. No positive samples for Bsal or ranavirus were recorded in any location. We confirmed the presence of Bd in 4 more localities and in 4 more species, including 1 urodelan (Macedonian crested newt Triturus macedonicus) and 1 introduced anuran (American bullfrog Lithobates catesbeianus). All insular localities were negative for Bd, except for Crete, where Bd was identified in 2 different locations. Again, no mass declines or die-offs were recorded in any Bd-positive area or elsewhere. However, given the persistence of Bd across Greece over the past ~20 yr, monitoring efforts should continue, and ideally be further expanded.
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Affiliation(s)
- Ilias Strachinis
- Department of Genetics, Development and Molecular Biology, School of Biology, Faculty of Natural Sciences, Aristotle University of Thessaloniki, 54636, Greece
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Scholz F, Vendramin N, Olesen NJ, Cuenca A, Moesgaard Iburg T, Mirimin L, O'Connor I, Ruane NM, Rodger HD, MacCarthy E. Experimental infection trials with European North Atlantic ranavirus (Iridoviridae) isolated from lumpfish (Cyclopterus lumpus, L.). JOURNAL OF FISH DISEASES 2022; 45:1745-1756. [PMID: 35989490 DOI: 10.1111/jfd.13696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 07/18/2022] [Accepted: 07/22/2022] [Indexed: 06/15/2023]
Abstract
European North Atlantic ranavirus (ENARV, Iridoviridae), is a ranavirus species recently isolated from lumpfish (Cyclopterus lumpus, L.), which are used as cleaner fish in Atlantic salmon (Salmo salar) farming in Northern Europe. This study aimed to investigate (1) the virulence of ENARV isolates from Ireland, Iceland and the Faroe Islands to lumpfish; (2) horizontal transmission between lumpfish; and (3) virulence to Atlantic salmon parr. Lumpfish were challenged in a cohabitation model using intraperitoneally (IP) injected shedders, and naïve cohabitants. IP challenge with isolates from Iceland (1.9 × 107 TCID50 ml-1 ) and the Faroe Islands (5.9 × 107 TCID50 ml-1 ) reduced survival in lumpfish, associated with consistent pathological changes. IP challenge with the Irish strain (8.6 × 105 TCID50 ml-1 ) did not significantly reduce survival in lumpfish, but the lower challenge titre complicated interpretation. Horizontal transmission occurred in all strains tested, but no clinical impact was demonstrated in cohabitants. Salmon parr were challenged by IP injection with the Irish isolate, no virulence or virus replication were demonstrated. A ranavirus qPCR assay, previously validated for fish ranaviruses, was first used to detect ENARV in tissues of both in lumpfish and Atlantic salmon. This study provides the first data on the assessment of virulence of ENARV isolates to lumpfish and salmon, guidelines for the diagnosis of ENARV infection, and poses a basis for further investigations into virulence markers.
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Affiliation(s)
- Felix Scholz
- PHARMAQ Analytiq, Oranmore, Ireland
- Marine and Freshwater Research Centre, Galway-Mayo Institute of Technology, Galway, Ireland
| | - Niccolò Vendramin
- DTU Aqua, National Institute of Aquatic Resources, Copenhagen, Denmark
| | | | - Argelia Cuenca
- DTU Aqua, National Institute of Aquatic Resources, Copenhagen, Denmark
| | | | - Luca Mirimin
- Marine and Freshwater Research Centre, Galway-Mayo Institute of Technology, Galway, Ireland
| | - Ian O'Connor
- Marine and Freshwater Research Centre, Galway-Mayo Institute of Technology, Galway, Ireland
| | | | | | - Eugene MacCarthy
- Marine and Freshwater Research Centre, Galway-Mayo Institute of Technology, Galway, Ireland
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Winter JM, Wellehan JFX, Apakupakul K, Palmer J, Brenn-White M, Standorf K, Berry KH, Childress AL, Koplos P, Garner MM, Deem SL. A novel herpesvirus detected in 3 species of chelonians. J Vet Diagn Invest 2022; 34:594-601. [PMID: 35459421 PMCID: PMC9266504 DOI: 10.1177/10406387221092048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Herpesviruses are found in free-living and captive chelonian populations, often in association with morbidity and mortality. To date, all known chelonian herpesviruses fall within the subfamily Alphaherpesvirinae. We detected a novel herpesvirus in 3 species of chelonians: a captive leopard tortoise (Stigmochelys pardalis) in western TX, USA; a steppe tortoise (Testudo [Agrionemys] horsfieldii) found near Fort Irwin, CA, USA; and 2 free-living, three-toed box turtles (Terrapene mexicana triunguis) found in Forest Park, St. Louis, MO. The leopard tortoise was coinfected with the tortoise intranuclear coccidian and had clinical signs of upper respiratory tract disease. The steppe tortoise had mucopurulent nasal discharge and lethargy. One of the three-toed box turtles had no clinical signs; the other was found dead with signs of trauma after being observed with blepharedema, tympanic membrane swelling, cervical edema, and other clinical signs several weeks prior to death. Generally, the branching order of the turtle herpesviruses mirrors the divergence patterns of their hosts, consistent with codivergence. Based on phylogenetic analysis, this novel herpesvirus clusters with a clade of viruses that infect emydid hosts and is likely of box turtle origin. Therefore, we suggest the name terrapene alphaherpesvirus 3 (TerAHV3) for the novel virus. This virus also has the ability to host-jump to tortoises, and previously documented herpesviral morbidity tends to be more common in aberrant hosts. The relationship between clinical signs and infection with TerAHV3 in these animals is unclear, and further investigation is merited.
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Affiliation(s)
- John M Winter
- College of Veterinary Medicine, University of Illinois, Urbana, IL, USA
| | - James F X Wellehan
- Zoological Medicine Service, Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA
| | | | - Jamie Palmer
- Institute for Conservation Medicine, Saint Louis Zoo, St. Louis, MO, USA
| | - Maris Brenn-White
- Institute for Conservation Medicine, Saint Louis Zoo, St. Louis, MO, USA
| | | | - Kristin H Berry
- Western Ecological Research Center, United States Geological Survey, Reno, NV, USA
| | - April L Childress
- Zoological Medicine Service, Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA
| | - Peter Koplos
- El Paso Veterinary Specialty Center, El Paso, TX, USA
| | | | - Sharon L Deem
- Institute for Conservation Medicine, Saint Louis Zoo, St. Louis, MO, USA
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Stilwell NK, Frasca S, Farina LL, Subramaniam K, Imnoi K, Viadanna PH, Hopper L, Powell J, Colee J, Waltzek TB. Effect of water temperature on frog virus 3 disease in hatchery-reared pallid sturgeon Scaphirhynchus albus. DISEASES OF AQUATIC ORGANISMS 2022; 148:73-86. [PMID: 35238323 DOI: 10.3354/dao03645] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Ranaviruses are large double-stranded DNA viruses within the genus Ranavirus (family Iridoviridae) that are being detected with increasing frequency among aquacultured and wild fishes. In the USA, multiple sturgeon hatcheries have experienced ranavirus epizootics resulting in significant morbidity and mortality in young-of-year (YOY). Significant economic losses have resulted from repeated outbreaks of frog virus 3 (FV3), the type species for the genus Ranavirus, in YOY pallid sturgeon Scaphirhynchus albus reared at a hatchery within the Missouri River Basin. Water temperature and stocking density are known to influence the severity of ranavirus disease in ectothermic vertebrates. To determine the effect of water temperature on ranavirus disease in hatchery-raised S. albus, we conducted FV3 challenges at 2 temperatures (17 and 23°C) and compared cumulative survival over a 28 d study period. A mean (±SE) survival rate of 57.5 ± 13.2% was observed in replicate tanks of sturgeon maintained at 23°C, whereas no mortality was observed among sturgeon maintained at 17°C. In a second challenge study, we compared the effect of water temperature on disease progression by regularly sampling fish over the study period and evaluating lesions by histopathology and in situ hybridization, and by assessing viral titer and load in external and internal tissues using virus isolation and qPCR, respectively. Results suggest that temperature manipulation may be an effective mitigation strategy that sturgeon hatcheries can employ to minimize ranavirus-associated disease.
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Affiliation(s)
- Natalie K Stilwell
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, USA
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Tornabene BJ, Crespi EJ, Traversari BA, Stemp KM, Breuner CW, Goldberg CS, Hossack BR. Low occurrence of ranavirus in the Prairie Pothole Region of Montana and North Dakota (USA) contrasts with prior surveys. DISEASES OF AQUATIC ORGANISMS 2021; 147:149-154. [PMID: 34913443 DOI: 10.3354/dao03640] [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: 06/14/2023]
Abstract
Ranaviruses are emerging pathogens that have caused mortality events in amphibians worldwide. Despite the negative effects of ranaviruses on amphibian populations, monitoring efforts are still lacking in many areas, including in the Prairie Pothole Region (PPR) of North America. Some PPR wetlands in Montana and North Dakota (USA) have been contaminated by energy-related saline wastewaters, and increased salinity has been linked to greater severity of ranavirus infections. In 2017, we tested tissues from larvae collected at 7 wetlands that ranged in salinity from 26 to 4103 mg Cl l-1. In 2019, we used environmental DNA (eDNA) to test for ranaviruses in 30 wetlands that ranged in salinity from 26 to 11754 mg Cl l-1. A previous study (2013-2014) found that ranavirus-infected amphibians were common across North Dakota, including in some wetlands near our study area. Overall, only 1 larva tested positive for ranavirus infection, and we did not detect ranavirus in any eDNA samples. There are several potential reasons why we found so little evidence of ranaviruses, including low larval sample sizes, mismatch between sampling and disease occurrence, larger pore size of our eDNA filters, temporal variation in outbreaks, low host abundance, or low occurrence or prevalence of ranaviruses in the wetlands we sampled. We suggest future monitoring efforts be conducted to better understand the occurrence and prevalence of ranaviruses within the PPR.
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Affiliation(s)
- Brian J Tornabene
- Wildlife Biology Program, W.A. Franke College of Forestry & Conservation, University of Montana, 32 Campus Drive, Missoula, MT 59812, USA
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Schüler L, Picquet P, Leineweber C, Dietz J, Müller E, Marschang RE. A testudinid herpesvirus 1 (TeHV1)-associated disease outbreak in a group of Horsfield's tortoises (Testudo horsfieldii). TIERARZTLICHE PRAXIS. AUSGABE K, KLEINTIERE/HEIMTIERE 2021; 49:462-467. [PMID: 34861723 DOI: 10.1055/a-1666-8378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In spring 2020, a severe disease outbreak with high morbidity and mortality was observed in a collection of 15 Horsfield's tortoises (Testudo horsfieldii). Affected tortoises showed upper respiratory- and gastrointestinal tract signs, including rhinitis and stomatitis. Testudinid herpesvirus 1 (TeHV1) and Mycoplasma spp. were detected by PCR in oral swabs of affected animals. Histological examination of one deceased animal showed intranuclear inclusion bodies typical for herpesvirus infections in liver, spleen and oesophagus. The virus was likely introduced into the collection 2 years earlier by a clinically healthy Horsfield's tortoise that was tested positive for TeHV1 by PCR.
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13
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Marschang RE, Salzmann E, Pees M. Diagnostics of Infectious Respiratory Pathogens in Reptiles. Vet Clin North Am Exot Anim Pract 2021; 24:369-395. [PMID: 33892892 DOI: 10.1016/j.cvex.2021.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Methods for the detection of pathogens associated with respiratory disease in reptiles, including viruses, bacteria, fungi, and parasites, are constantly evolving as is the understanding of the specific roles played by various pathogens in disease processes. Some are known to be primary pathogens with high prevalence in captive reptiles, for example, serpentoviruses in pythons or mycoplasma in tortoises. Others are very commonly found in reptiles with respiratory disease but are most often considered secondary, for example, gram-negative bacteria. Detection methods as well as specific pathogens associated with upper- and lower-respiratory disease are discussed.
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Affiliation(s)
| | | | - Michael Pees
- Department for Birds and Reptiles, University Veterinary Teaching Hospital, University of Leipzig, Clinic for Birds and Reptiles, An den Tierkliniken 17, Leipzig 04103, Germany
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14
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Ferreira CM, Subramaniam K, de Sousa RLM, Tavares LS, Corrêa TC, Waltzek TB. Genomic sequencing of a frog virus 3 strain from cultured American bullfrogs (Lithobates catesbeianus) in Brazil. Arch Virol 2021; 166:1961-1964. [PMID: 33983503 DOI: 10.1007/s00705-021-05094-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 03/22/2021] [Indexed: 11/25/2022]
Abstract
Frog virus 3 (FV3) was detected in cultured bullfrogs in Southeast Brazil. Phylodynamic analysis revealed recombination events in this strain that were nearly identical to those detected in North American and Brazilian FV3 strains. These data suggest that international trade of live bullfrogs has spread recombinant strains of FV3.
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Affiliation(s)
- Claudia Maris Ferreira
- Fisheries Institute, APTA, SAA, Av Francisco Matarazzo, 455, Agua Branca, São Paulo, Brazil.
| | - Kuttichantran Subramaniam
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA
| | | | | | - Thaís C Corrêa
- University of São Paulo, USP, FZEA, Pirassununga, Brazil
| | - Thomas B Waltzek
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA
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15
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Yu Z, Wu H, Huang Q, Zhong Z. Simultaneous detection of Marburg virus and Ebola virus with TaqMan-based multiplex real-time PCR method. J Clin Lab Anal 2021; 35:e23786. [PMID: 33939238 PMCID: PMC8183904 DOI: 10.1002/jcla.23786] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 03/18/2021] [Accepted: 03/31/2021] [Indexed: 12/27/2022] Open
Abstract
Background Marburg virus (MARV) and Ebola virus (EBOV) are acute infections with high case fatality rates. It is of great significance for epidemic monitoring and prevention and control of infectious diseases by the development of a rapid, specific, and sensitive quantitative PCR method to detect two pathogens simultaneously. Methods Primers and TaqMan probes were designed according to highly conserved sequences of these viruses. Sensitivity, specificity, linear range, limit of detection, and the effects of hemolysis and lipid on real‐time qPCR were evaluated. Results The linearity of the curve allowed quantification of nucleic acid concentrations in range from 103 to 109 copies/ml per reaction (MARV and EBOV). The limit of detection of EBOV was 40 copies/ml, and MARV was 100 copies/ml. It has no cross‐reaction with other pathogens such as hepatitis b virus (HBV), hepatitis c virus (HCV), human papillomavirus (HPV), Epstein‐Barr virus (EBV), herpes simplex virus (HSV), cytomegalovirus (CMV), and human immunodeficiency virus (HIV). Repeatability analysis of the two viruses showed that their coefficient of variation (CV) was less than 5.0%. The above results indicated that fluorescence quantitative PCR could detect EBOV and MARV sensitively and specifically. Conclusions The TaqMan probe‐based multiplex fluorescence quantitative PCR assays could detect EBOV and MARV sensitively specifically and simultaneously.
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Affiliation(s)
- Zhikang Yu
- Center for Precision Medicine, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China.,Guangdong Provincial Key Laboratory of Precision Medicine and Clinical Translational Research of Hakka Population, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China.,Guangdong Provincial Engineering and Technology Research Center for Clinical Molecular Diagnostics and Antibody Therapeutics, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China
| | - Heming Wu
- Center for Precision Medicine, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China.,Guangdong Provincial Key Laboratory of Precision Medicine and Clinical Translational Research of Hakka Population, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China.,Guangdong Provincial Engineering and Technology Research Center for Clinical Molecular Diagnostics and Antibody Therapeutics, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China
| | - Qingyan Huang
- Center for Precision Medicine, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China.,Guangdong Provincial Key Laboratory of Precision Medicine and Clinical Translational Research of Hakka Population, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China.,Guangdong Provincial Engineering and Technology Research Center for Clinical Molecular Diagnostics and Antibody Therapeutics, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China
| | - Zhixiong Zhong
- Center for Precision Medicine, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China.,Guangdong Provincial Key Laboratory of Precision Medicine and Clinical Translational Research of Hakka Population, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China.,Guangdong Provincial Engineering and Technology Research Center for Clinical Molecular Diagnostics and Antibody Therapeutics, Meizhou People's Hospital (Huangtang Hospital), Meizhou Academy of Medical Sciences, Meizhou Hospital Affiliated to Sun Yat-sen University, Meizhou, China
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16
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Genome Sequence of a Ranavirus Isolated from a Red-Eared Slider (Trachemys scripta elegans) in Poland. Microbiol Resour Announc 2020; 9:9/47/e00781-20. [PMID: 33214291 PMCID: PMC7679084 DOI: 10.1128/mra.00781-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The red-eared slider (RES) ranavirus (RESRV) was isolated from a free-ranging RES turtle that died with evidence of respiratory disease. The RESRV genome sequence (106,878 bp) was determined, and phylogenetic analysis revealed that it is a common midwife toad virus (CMTV) strain. This study is the first report of CMTV in RES.
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17
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Brunner JL, Olson AD, Rice JG, Meiners SE, Le Sage MJ, Cundiff JA, Goldberg CS, Pessier AP. Ranavirus infection dynamics and shedding in American bullfrogs: consequences for spread and detection in trade. DISEASES OF AQUATIC ORGANISMS 2019; 135:135-150. [PMID: 31392966 DOI: 10.3354/dao03387] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
American bullfrogs Lithobates catesbeianus are thought to be important in the global spread of ranaviruses-often lethal viruses of cold-blooded vertebrates-because they are commonly farmed, dominate international trade, and may be 'carriers' of ranavirus infections. However, whether American bullfrogs are easily infected and maintain long-lasting ranavirus infections, or are refractory to or rapidly clear infections, remains unknown. We tracked the dynamics of ranavirus in American bullfrogs through time and with temperature in multiple types of samples and also screened shipments from commercial suppliers to determine whether we could detect subclinical infections. Collectively, we found that tadpoles and juveniles were commonly infected at moderate doses, and while some died, others controlled and appeared to clear their infections. Some individuals, however, harbored subclinical infections for up to 49 d, suggesting that American bullfrogs may be important carriers. Indeed, tadpoles and metamorphosed frogs from 2 of 5 commercial suppliers harbored subclinicial infections. Juveniles at warmer temperatures had less intense but still persistent infections. Because diagnostic performance was strongly related to infection intensity, non-lethal samples (i.e. tail or toe clips, swabs, and environmental DNA) had only a moderate chance of detecting subclinical infections. Even internal tissues may fail to detect subclinical infections. However, viral shedding was correlated with the intensity of infection, so while subclinically infected tadpoles shed virus for 35-49 d, the low levels might lead to little transmission. We suggest that a quantitative focus on virus dynamics within hosts can provide a more nuanced view of ranavirus infections and the risk presented by American bullfrogs in trade.
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Affiliation(s)
- Jesse L Brunner
- School of Biological Sciences, Washington State University, Pullman, WA 99164, USA
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18
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Mihaljevic JR, Greer AL, Brunner JL. Evaluating the Within-Host Dynamics of Ranavirus Infection with Mechanistic Disease Models and Experimental Data. Viruses 2019; 11:E396. [PMID: 31035560 PMCID: PMC6563243 DOI: 10.3390/v11050396] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 04/23/2019] [Accepted: 04/25/2019] [Indexed: 11/30/2022] Open
Abstract
Mechanistic models are critical for our understanding of both within-host dynamics (i.e., pathogen replication and immune system processes) and among-host dynamics (i.e., transmission). Within-host models, however, are not often fit to experimental data, which can serve as a robust method of hypothesis testing and hypothesis generation. In this study, we use mechanistic models and empirical, time-series data of viral titer to better understand the replication of ranaviruses within their amphibian hosts and the immune dynamics that limit viral replication. Specifically, we fit a suite of potential models to our data, where each model represents a hypothesis about the interactions between viral replication and immune defense. Through formal model comparison, we find a parsimonious model that captures key features of our time-series data: The viral titer rises and falls through time, likely due to an immune system response, and that the initial viral dosage affects both the peak viral titer and the timing of the peak. Importantly, our model makes several predictions, including the existence of long-term viral infections, which can be validated in future studies.
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Affiliation(s)
- Joseph R Mihaljevic
- School of Informatics, Computing and Cyber Systems, Northern Arizona University, Flagstaff, AZ 86011, USA.
| | - Amy L Greer
- Department of Population Medicine, University of Guelph, Guelph, ON N1G 2W1, Canada.
| | - Jesse L Brunner
- School of Biological Sciences, Washington State University, Pullman, WA 99163, USA.
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19
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Le Sage MJ, Towey BD, Brunner JL. Do scavengers prevent or promote disease transmission? The effect of invertebrate scavenging on
Ranavirus
transmission. Funct Ecol 2019. [DOI: 10.1111/1365-2435.13335] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Mitchell J. Le Sage
- School of Biological Sciences Washington State University Pullman Washington
| | - Bailey D. Towey
- School of Biological Sciences Washington State University Pullman Washington
| | - Jesse L. Brunner
- School of Biological Sciences Washington State University Pullman Washington
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20
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Becker JA, Gilligan D, Asmus M, Tweedie A, Whittington RJ. Geographic Distribution of Epizootic haematopoietic necrosis virus (EHNV) in Freshwater Fish in South Eastern Australia: Lost Opportunity for a Notifiable Pathogen to Expand Its Geographic Range. Viruses 2019; 11:v11040315. [PMID: 30939801 PMCID: PMC6520861 DOI: 10.3390/v11040315] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 03/26/2019] [Accepted: 03/28/2019] [Indexed: 11/23/2022] Open
Abstract
Epizootic haematopoietic necrosis virus (EHNV) was originally detected in Victoria, Australia in 1984. It spread rapidly over two decades with epidemic mortality events in wild redfin perch (Perca fluviatilis) and mild disease in farmed rainbow trout (Oncorhynchus mykiss) being documented across southeastern Australia in New South Wales (NSW), the Australian Capital Territory (ACT), Victoria, and South Australia. We conducted a survey for EHNV between July 2007 and June 2011. The disease occurred in juvenile redfin perch in ACT in December 2008, and in NSW in December 2009 and December 2010. Based on testing 3622 tissue and 492 blood samples collected from fish across southeastern Australia, it was concluded that EHNV was most likely absent from redfin perch outside the endemic area in the upper Murrumbidgee River catchment in the Murray–Darling Basin (MDB), and it was not detected in other fish species. The frequency of outbreaks in redfin perch has diminished over time, and there have been no reports since 2012. As the disease is notifiable and a range of fish species are known to be susceptible to EHNV, existing policies to reduce the likelihood of spreading out of the endemic area are justified.
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Affiliation(s)
- Joy A Becker
- Sydney School of Veterinary Science, The University of Sydney, Camden 2570, Australia.
| | - Dean Gilligan
- NSW Industry and Investment, Batemans Bay Fisheries Office, Batemans Bay 2536, Australia.
| | - Martin Asmus
- NSW Industry and Investment, Narrandera Fisheries Centre, Narrandera 2700, Australia.
| | - Alison Tweedie
- Sydney School of Veterinary Science, The University of Sydney, Camden 2570, Australia.
| | - Richard J Whittington
- Sydney School of Veterinary Science, The University of Sydney, Camden 2570, Australia.
- OIE Reference Laboratory for Epizootic Haematopoietic Necrosis Virus and Ranavirus Infection of Amphibians, Sydney School of Veterinary Science, The University Sydney, Camden 2570, Australia.
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21
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Seasonal dynamics and potential drivers of ranavirus epidemics in wood frog populations. Oecologia 2018; 188:1253-1262. [DOI: 10.1007/s00442-018-4274-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 10/14/2018] [Indexed: 12/22/2022]
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