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8 pages, 233 KiB

Open AccessArticle

Assessing the Efficacy of Three Hatchery Disinfectants for the Inactivation of a Lake Sturgeon Herpesvirus (Family: Alloherpesviridae)

by Amber E. Johnston, Megan A. Shavalier, Kim T. Scribner, Esteban Soto, Susan Yun and Thomas P. Loch

Viruses 2024, 16(7), 1062; https://doi.org/10.3390/v16071062 - 30 Jun 2024

Viewed by 1686

Abstract

Infectious diseases are a leading cause of losses in the aquaculture industry and conservation programs globally. Simultaneously, infectious diseases pose a substantial risk to fish being hatchery-reared and released into natural habitats for conservation purposes, including the Great Lakes lake sturgeon (Acipenser [...] Read more.

Infectious diseases are a leading cause of losses in the aquaculture industry and conservation programs globally. Simultaneously, infectious diseases pose a substantial risk to fish being hatchery-reared and released into natural habitats for conservation purposes, including the Great Lakes lake sturgeon (Acipenser fulvescens, i.e., GL-LST). Recently, an alloherpesvirus (lake sturgeon herpesvirus 2, i.e., LSHV-2) capable of inducing disease and/or mortality in adult and juvenile GL-LSTs was detected in two adult GL-LST populations. To begin developing disease prevention and/or control methods, in vitro experiments were designed to determine the susceptibility of LSHV-2 to disinfectants commonly used in hatchery and aquaculture facilities (Virkon^®-Aquatic: potassium peroxymonosulfate; Ovadine^®: polyvinylpyrrolidone iodine complex; and Perox-Aid^®: hydrogen peroxide). Cultured LSHV-2 was exposed to each disinfectant at two concentrations (Virkon^®-Aquatic: 0.5% and 1%; Ovadine^®: 50 and 100 ppm; and Perox-Aid^®: 500 and 1000 ppm) in duplicate for durations of 1, 10, and 30 min. Following exposure, the disinfectant was neutralized, and after a 14-day incubation period on a white sturgeon × lake sturgeon hybrid cell line (WSxLS), percent reduction was calculated by comparing the 50% tissue culture infectious doses (TCID₅₀/mL) of the virus with and without disinfectant exposure. When exposed to Perox-Aid^®, LSHV-2 percent reduction ranged from 58.7% to 99.5%. When exposed to Ovadine^®, the percent reduction ranged from 99.4% to 100%. Lastly, the percent reduction when exposed to Virkon^®-Aquatic was 100% for both concentrations and all timepoints. The results herein provide evidence that both Virkon^®-Aquatic and Ovadine^® are virucidal to LSHV-2 and may represent a means to reduce virus transmission risk under field settings. Full article

(This article belongs to the Special Issue Identifying and Characterizing Viral Infections in Reptiles, Amphibians, Fish and Other Aquatic Species)

16 pages, 2580 KiB

Open AccessArticle

Discovery and Genomic Characterization of a Novel Hepadnavirus from Asymptomatic Anadromous Alewife (Alosa pseudoharengus)

by Clayton Raines, Jan Lovy, Nicolas Phelps, Sunil Mor, Terry Fei Fan Ng and Luke Iwanowicz

Viruses 2024, 16(6), 824; https://doi.org/10.3390/v16060824 - 22 May 2024

Viewed by 1422

Abstract

The alewife (Alosa pseudoharengus) is an anadromous herring that inhabits waters of northeastern North America. This prey species is a critical forage for piscivorous birds, mammals, and fishes in estuarine and oceanic ecosystems. During a discovery project tailored to identify potentially emerging [...] Read more.

The alewife (Alosa pseudoharengus) is an anadromous herring that inhabits waters of northeastern North America. This prey species is a critical forage for piscivorous birds, mammals, and fishes in estuarine and oceanic ecosystems. During a discovery project tailored to identify potentially emerging pathogens of this species, we obtained the full genome of a novel hepadnavirus (ApHBV) from clinically normal alewives collected from the Maurice River, Great Egg Harbor River, and Delaware River in New Jersey, USA during 2015–2018. This previously undescribed hepadnavirus contained a circular DNA genome of 3146 nucleotides. Phylogenetic analysis of the polymerase protein placed this virus in the clade of metahepadnaviruses (family: Hepadnaviridae; genus: Metahepadnavirus). There was no evidence of pathology in the internal organs of infected fish and virions were not observed in liver tissues by electron microscopy. We developed a Taqman-based quantitative (qPCR) assay and screened 182 individuals collected between 2015 and 2018 and detected additional qPCR positives (n = 6). An additional complete genome was obtained in 2018 and it has 99.4% genome nucleotide identity to the first virus. Single-nucleotide polymorphisms were observed between the two genomes, including 7/9 and 12/8 synonymous vs nonsynonymous mutations across the polymerase and surface proteins, respectively. While there was no evidence that this virus was associated with disease in this species, alewives are migratory interjurisdictional fishes of management concern. Identification of microbial agents using de novo sequencing and other advanced technologies is a critical aspect of understanding disease ecology for informed population management. Full article

(This article belongs to the Special Issue Identifying and Characterizing Viral Infections in Reptiles, Amphibians, Fish and Other Aquatic Species)

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12 pages, 2421 KiB

Open AccessArticle

Phylogenomic Characterization of Ranavirus Isolated from Wild Smallmouth Bass (Micropterus dolomieu)

by Hannah Quail, Pedro H. O. Viadanna, Jordan A. Vann, Hui-Min Hsu, Andrea Pohly, Willow Smith, Scott Hansen, Nicole Nietlisbach, Danielle Godard, Thomas B. Waltzek and Kuttichantran Subramaniam

Viruses 2024, 16(5), 715; https://doi.org/10.3390/v16050715 - 30 Apr 2024

Cited by 1 | Viewed by 2019

Abstract

In September 2021, 14 smallmouth bass (SMB; Micropterus dolomieu) with skin lesions were collected from Green Bay waters of Lake Michigan and submitted for diagnostic evaluation. All the skin samples tested positive for largemouth bass virus (LMBV) by conventional PCR. The complete genome [...] Read more.

In September 2021, 14 smallmouth bass (SMB; Micropterus dolomieu) with skin lesions were collected from Green Bay waters of Lake Michigan and submitted for diagnostic evaluation. All the skin samples tested positive for largemouth bass virus (LMBV) by conventional PCR. The complete genome of the LMBV (99,328 bp) isolated from a homogenized skin sample was determined using an Illumina MiSeq sequencer. A maximum likelihood (ML) phylogenetic analysis based on the 21 core iridovirus genes supported the LMBV isolated from SMB (LMBV-WVL21117) as a member of the species Santee-Cooper ranavirus. Pairwise nucleotide comparison of the major capsid protein (MCP) gene showed that LMBV-WVL21117 is identical to other LMBV reported from the United States and nearly identical to doctor fish virus and guppy virus 6 (99.2%) from Southeast Asia, as well as LMBV isolates from China and Thailand (99.1%). In addition, ML phylogenetic analysis based on the MCP gene suggests three genotypes of LMBV separated by region: genotype one from the United States, genotype two from Southeast Asia, and genotype three from China and Thailand. Additional research is needed to understand the prevalence and genetic diversity of LMBV strains circulating in wild and managed fish populations from different regions. Full article

(This article belongs to the Special Issue Identifying and Characterizing Viral Infections in Reptiles, Amphibians, Fish and Other Aquatic Species)

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11 pages, 1681 KiB

Open AccessArticle

First Report of Endemic Frog Virus 3 (FV3)-like Ranaviruses in the Korean Clawed Salamander (Onychodactylus koreanus) in Asia

by Jongsun Kim, Haan Woo Sung, Tae Sung Jung, Jaejin Park and Daesik Park

Viruses 2024, 16(5), 675; https://doi.org/10.3390/v16050675 - 25 Apr 2024

Viewed by 1303

Abstract

Frog virus 3 (FV3) in the genus Ranavirus of the family Iridoviridae causes mass mortality in both anurans and urodeles worldwide; however, the phylogenetic origin of FV3-like ranaviruses is not well established. In Asia, three FV3-like ranaviruses have been reported in farmed populations [...] Read more.

Frog virus 3 (FV3) in the genus Ranavirus of the family Iridoviridae causes mass mortality in both anurans and urodeles worldwide; however, the phylogenetic origin of FV3-like ranaviruses is not well established. In Asia, three FV3-like ranaviruses have been reported in farmed populations of amphibians and reptiles. Here, we report the first case of endemic FV3-like ranavirus infections in the Korean clawed salamander Onychodactylus koreanus, caught in wild mountain streams in the Republic of Korea (ROK), through whole-genome sequencing and phylogenetic analysis. Two isolated FV3-like ranaviruses (Onychodactylus koreanus ranavirus, OKRV1 and 2) showed high similarity with the Rana grylio virus (RGV, 91.5%) and Rana nigromaculata ranavirus (RNRV, 92.2%) but relatively low similarity with the soft-shelled turtle iridovirus (STIV, 84.2%) in open reading frame (ORF) comparisons. OKRV1 and 2 formed a monophyletic clade with previously known Asian FV3-like ranaviruses, a sister group of the New World FV3-like ranavirus clade. Our results suggest that OKRV1 and 2 are FV3-like ranaviruses endemic to the ROK, and RGV and RNRV might also be endemic strains in China, unlike previous speculation. Our data have great implications for the study of the phylogeny and spreading routes of FV3-like ranaviruses and suggest the need for additional detection and analysis of FV3-like ranaviruses in wild populations in Asian countries. Full article

(This article belongs to the Special Issue Identifying and Characterizing Viral Infections in Reptiles, Amphibians, Fish and Other Aquatic Species)

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18 pages, 671 KiB

Open AccessArticle

Delving into the Aftermath of a Disease-Associated Near-Extinction Event: A Five-Year Study of a Serpentovirus (Nidovirus) in a Critically Endangered Turtle Population

by Kate Parrish, Peter Kirkland, Paul Horwood, Bruce Chessman, Shane Ruming, Gerry McGilvray, Karrie Rose, Jane Hall and Lee Skerratt

Viruses 2024, 16(4), 653; https://doi.org/10.3390/v16040653 - 22 Apr 2024

Viewed by 1473

Abstract

Bellinger River virus (BRV) is a serpentovirus (nidovirus) that was likely responsible for the catastrophic mortality of the Australian freshwater turtle Myuchelys georgesi in February 2015. From November 2015 to November 2020, swabs were collected from turtles during repeated river surveys to estimate [...] Read more.

Bellinger River virus (BRV) is a serpentovirus (nidovirus) that was likely responsible for the catastrophic mortality of the Australian freshwater turtle Myuchelys georgesi in February 2015. From November 2015 to November 2020, swabs were collected from turtles during repeated river surveys to estimate the prevalence of BRV RNA, identify risk factors associated with BRV infection, and refine sample collection. BRV RNA prevalence at first capture was significantly higher in M. georgesi (10.8%) than in a coexisting turtle, Emydura macquarii (1.0%). For M. georgesi, various risk factors were identified depending on the analysis method, but a positive BRV result was consistently associated with a larger body size. All turtles were asymptomatic when sampled and conjunctival swabs were inferred to be optimal for ongoing monitoring. Although the absence of disease and recent BRV detections suggests a reduced ongoing threat, the potential for the virus to persist in an endemic focus or resurge in cyclical epidemics cannot be excluded. Therefore, BRV is an ongoing potential threat to the conservation of M. georgesi, and strict adherence to biosecurity principles is essential to minimise the risk of reintroduction or spread of BRV or other pathogens. Full article

(This article belongs to the Special Issue Identifying and Characterizing Viral Infections in Reptiles, Amphibians, Fish and Other Aquatic Species)

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21 pages, 4654 KiB

Open AccessArticle

Serpentoviruses Exhibit Diverse Organization and ORF Composition with Evidence of Recombination

by Steven B. Tillis, Robert J. Ossiboff and James F. X. Wellehan, Jr.

Viruses 2024, 16(2), 310; https://doi.org/10.3390/v16020310 - 18 Feb 2024

Cited by 1 | Viewed by 2150

Abstract

Serpentoviruses are a subfamily of positive sense RNA viruses in the order Nidovirales, family Tobaniviridae, associated with respiratory disease in multiple clades of reptiles. While the broadest viral diversity is reported from captive pythons, other reptiles, including colubrid snakes, turtles, and lizards [...] Read more.

Serpentoviruses are a subfamily of positive sense RNA viruses in the order Nidovirales, family Tobaniviridae, associated with respiratory disease in multiple clades of reptiles. While the broadest viral diversity is reported from captive pythons, other reptiles, including colubrid snakes, turtles, and lizards of captive and free-ranging origin are also known hosts. To better define serpentoviral diversity, eleven novel serpentovirus genomes were sequenced with an Illumina MiSeq and, when necessary, completed with other Sanger sequencing methods. The novel serpentoviral genomes, along with 57 other previously published serpentovirus genomes, were analyzed alongside four outgroup genomes. Genomic analyses included identifying unique genome templates for each serpentovirus clade, as well as analysis of coded protein composition, potential protein function, protein glycosylation sites, differences in phylogenetic history between open-reading frames, and recombination. Serpentoviral genomes contained diverse protein compositions. In addition to the fundamental structural spike, matrix, and nucleoprotein proteins required for virion formation, serpentovirus genomes also included 20 previously uncharacterized proteins. The uncharacterized proteins were homologous to a number of previously characterized proteins, including enzymes, transcription factors, scaffolding, viral resistance, and apoptosis-related proteins. Evidence for recombination was detected in multiple instances in genomes from both captive and free-ranging snakes. These results show serpentovirus as a diverse clade of viruses with genomes that code for a wide diversity of proteins potentially enhanced by recombination events. Full article

(This article belongs to the Special Issue Identifying and Characterizing Viral Infections in Reptiles, Amphibians, Fish and Other Aquatic Species)

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14 pages, 1932 KiB

Open AccessArticle

Features of SARS-CoV-2 Replication in Various Types of Reptilian and Fish Cell Cultures

by Yulia Kononova, Lyubov Adamenko, Evgeniya Kazachkova, Mariya Solomatina, Svetlana Romanenko, Anastasia Proskuryakova, Yaroslav Utkin, Marina Gulyaeva, Anastasia Spirina, Elena Kazachinskaia, Natalia Palyanova, Oksana Mishchenko, Alexander Chepurnov and Alexander Shestopalov

Viruses 2023, 15(12), 2350; https://doi.org/10.3390/v15122350 - 29 Nov 2023

Viewed by 1924

Abstract

Background: SARS-CoV-2 can enter the environment from the feces of COVID-19 patients and virus carriers through untreated sewage. The virus has shown the ability to adapt to a wide range of hosts, so the question of the possible involvement of aquafauna and animals [...] Read more.

Background: SARS-CoV-2 can enter the environment from the feces of COVID-19 patients and virus carriers through untreated sewage. The virus has shown the ability to adapt to a wide range of hosts, so the question of the possible involvement of aquafauna and animals of coastal ecosystems in maintaining its circulation remains open. Methods: the aim of this work was to study the tropism of SARS-CoV-2 for cells of freshwater fish and reptiles, including those associated with aquatic and coastal ecosystems, and the effect of ambient temperature on this process. In a continuous cell culture FHM (fathead minnow) and diploid fibroblasts CGIB (silver carp), SARS-CoV-2 replication was not maintained at either 25 °C or 29 °C. At 29 °C, the continuous cell culture TH-1 (eastern box turtle) showed high susceptibility to SARS-CoV-2, comparable to Vero E6 (development of virus-induced cytopathic effect (CPE) and an infectious titer of 7.5 ± 0.17 log₁₀ TCID₅₀/mL on day 3 after infection), and primary fibroblasts CNI (Nile crocodile embryo) showed moderate susceptibility (no CPE, infectious titer 4.52 ± 0.14 log₁₀ TCID₅₀/mL on day 5 after infection). At 25 °C, SARS-CoV-2 infection did not develop in TH-1 and CNI. Conclusions: our results show the ability of SARS-CoV-2 to effectively replicate without adaptation in the cells of certain reptile species when the ambient temperature rises. Full article

(This article belongs to the Special Issue Identifying and Characterizing Viral Infections in Reptiles, Amphibians, Fish and Other Aquatic Species)

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21 pages, 2040 KiB

Open AccessArticle

A Multiplex RT-PCR Method for the Detection of Reptarenavirus Infection

by Francesca Baggio, Udo Hetzel, Barbara Prähauser, Eva Dervas, Eleni Michalopoulou, Tanja Thiele, Anja Kipar and Jussi Hepojoki

Viruses 2023, 15(12), 2313; https://doi.org/10.3390/v15122313 - 25 Nov 2023

Cited by 3 | Viewed by 1609

Abstract

Reptarenaviruses cause Boid Inclusion Body Disease (BIBD), a fatal disease of boid snakes with an economic and ecological impact, as it affects both captive and wild constrictor snakes. The clinical picture of BIBD is highly variable but often only limited. Intracytoplasmic inclusion bodies [...] Read more.

Reptarenaviruses cause Boid Inclusion Body Disease (BIBD), a fatal disease of boid snakes with an economic and ecological impact, as it affects both captive and wild constrictor snakes. The clinical picture of BIBD is highly variable but often only limited. Intracytoplasmic inclusion bodies (IB), which develop in most cell types including blood cells, are the pathognomonic hallmark of BIBD; their detection represents the diagnostic gold standard of the disease. However, IBs are not consistently present in clinically healthy reptarenavirus carriers, which can, if undetected, lead to and maintain the spread of the disease within and between snake populations. Sensitive viral detection tools are required for screening and control purposes; however, the genetic diversity of reptarenaviruses hampers the reverse transcription (RT) PCR-based diagnostics. Here, we describe a multiplex RT-PCR approach for the molecular diagnosis of reptarenavirus infection in blood samples. The method allows the detection of a wide range of reptarenaviruses with the detection limit reaching 40 copies per microliter of blood. Using 245 blood samples with a reference RT-PCR result, we show that the technique performs as well as the segment-specific RT-PCRs in our earlier studies. It can identify virus carriers and serve to limit reptarenavirus spreading in captive snake collections. Full article

(This article belongs to the Special Issue Identifying and Characterizing Viral Infections in Reptiles, Amphibians, Fish and Other Aquatic Species)

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