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Zeng R, Fu J, Pan W, Zhan Z, Weng S, Guo C, He J. Low-temperature immunization attenuates the residual virulence of orf074r gene-deleted infectious spleen and kidney necrosis virus: a candidate immersion vaccine. J Virol 2023; 97:e0128923. [PMID: 37933966 PMCID: PMC10688326 DOI: 10.1128/jvi.01289-23] [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: 08/23/2023] [Accepted: 10/06/2023] [Indexed: 11/08/2023] Open
Abstract
IMPORTANCE Global aquaculture production yielded a record of 122.9 million tons in 2022. However, ~10% of farmed aquatic animal production is lost each year due to various infectious diseases, resulting in substantial economic waste. Therefore, the development of vaccines is important for the prevention and control of aquatic infectious diseases. Gene-deletion live attenuated vaccines are efficacious because they mimic natural pathogen infection and generate a strong antibody response, thus showing good potential for administration via immersion. However, most gene-deletion viruses still have residual virulence, and thus, gene-deletion immersion vaccines for aquatic viruses are rarely developed. In this study, an orf074r deletion strain (Δorf074r) of ISKNV with residual virulence was constructed, and an immunization process was developed to reduce its residual virulence at 22°C, thereby making it a potential immersion vaccine against ISKNV. Our work will aid in the development of an aquatic gene-deletion live-attenuated immersion vaccine.
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Affiliation(s)
- Ruoyun Zeng
- State Key Laboratory for Biocontrol / Southern Laboratory of Ocean Science and Engineering (Guangdong, Zhuhai), School of Marine Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Marine Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Jiajie Fu
- State Key Laboratory for Biocontrol / Southern Laboratory of Ocean Science and Engineering (Guangdong, Zhuhai), School of Marine Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Marine Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Weiqiang Pan
- State Key Laboratory for Biocontrol / Southern Laboratory of Ocean Science and Engineering (Guangdong, Zhuhai), School of Marine Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Marine Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Zhipeng Zhan
- State Key Laboratory for Biocontrol / Southern Laboratory of Ocean Science and Engineering (Guangdong, Zhuhai), School of Marine Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Marine Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Shaoping Weng
- State Key Laboratory for Biocontrol / Southern Laboratory of Ocean Science and Engineering (Guangdong, Zhuhai), School of Marine Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Marine Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Changjun Guo
- State Key Laboratory for Biocontrol / Southern Laboratory of Ocean Science and Engineering (Guangdong, Zhuhai), School of Marine Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Marine Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, Guangdong, China
| | - Jianguo He
- State Key Laboratory for Biocontrol / Southern Laboratory of Ocean Science and Engineering (Guangdong, Zhuhai), School of Marine Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Marine Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
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Goodman RM, Carman HR, Mahaffy RP, Cabrera NS. Trace Amounts of Ranavirus Detected in Common Musk Turtles ( Sternotherus odoratus) at a Site Where the Pathogen Was Previously Common. Animals (Basel) 2023; 13:2951. [PMID: 37760351 PMCID: PMC10526040 DOI: 10.3390/ani13182951] [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: 08/15/2023] [Revised: 09/07/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023] Open
Abstract
Ranaviruses are global multi-host pathogens that infect ectothermic vertebrates and cause mass mortality events in some species. In 2021-2022, we surveyed two species of aquatic turtles in a Virginia site where previous research found ranavirus in lizards (Sceloporus undulatus) and turtles (Chrysemys picta picta and Terrapene carolina carolina). We sampled tissues from 206 turtles and tested 249 samples (including recaptures) for ranavirus using qPCR. We detected trace amounts of ranavirus DNA in 2.8% of Common Musk Turtles (Sternotherus odoratus). We did not detect the virus in Eastern Painted Turtles (C. p. picta). The Ct values from animals carrying ranavirus corresponded to positive controls with a concentration of one copy of ranavirus DNA per microliter and likely reflect DNA in the environment rather than ranavirus infection in turtles. Turtles carrying ranavirus DNA came from only one pond in one year. The amount of ranavirus in our study site, as indicated by tissue samples from turtles, appears to have dropped dramatically since previous research conducted over a decade ago. This study represents the first report of ranavirus detected in S. odoratus and contributes to the scarce literature on longitudinal surveys of ranavirus in wild chelonians. We emphasize the need for large sample sizes and multi-year sampling to detect this pathogen in wild populations.
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Affiliation(s)
- Rachel M. Goodman
- Department of Biology, Hampden-Sydney College, Hampden-Sydney, VA 23943, USA;
| | - Henry R. Carman
- The Watershed Research and Training Center, Hayfork, CA 96041, USA;
| | - R. Paul Mahaffy
- School of Physical Therapy, University of Lynchburg, Lynchburg, VA 24502, USA;
| | - Nathan S. Cabrera
- Department of Biology, Hampden-Sydney College, Hampden-Sydney, VA 23943, USA;
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McKnight DT, Ard K, Auguste RJ, Barhadiya G, Benard MF, Boban P, Dillon ML, Downs CT, DeGregorio BA, Glorioso BM, Goodman RM, Hird C, Hollender EC, Kennedy M, Kidman RA, Massey A, McGovern P, Mühlenhaupt M, Ostovar K, Podgorski D, Price C, Reinke BA, Streeting LM, Venezia J, Young J, Nordberg EJ. Nocturnal basking in freshwater turtles: a global assessment. Glob Ecol Conserv 2023. [DOI: 10.1016/j.gecco.2023.e02444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023] Open
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Wirth W, Forzán MJ, Schwarzkopf L, Ariel E. Pathogenesis of Bohle iridovirus infection in Krefft's freshwater turtle hatchlings ( Emydura macquarii krefftii). Vet Pathol 2023; 60:139-150. [PMID: 36086869 DOI: 10.1177/03009858221122591] [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: 01/31/2023]
Abstract
Ranaviruses have been detected in over 12 families of reptiles including many genera of turtles, tortoises, and terrapins, but the pathogenesis of these infections is still poorly understood. Krefft's river turtle hatchlings (N = 36; Emydura macquarii krefftii) were inoculated intramuscularly with Bohle iridovirus (BIV, Ranavirus, isolate) or saline, and euthanized at 9 timepoints (3 infected and 1 control per timepoint) over a 24-day period. Samples of lung, liver, kidney, and spleen were collected for quantitative polymerase chain reaction (PCR); internal organs, skin, and oral cavity samples were fixed for histopathological examination. The earliest lesions, at 8 days postinoculation (dpi), were lymphocytic inflammation of the skin and fibrinoid necrosis of regional vessels at the site of inoculation, and mild ulcerative necrosis with lymphocytic and heterophilic inflammation in the oral, nasal, and tongue mucosae. Fibrinonecrotic foci with heterophilic inflammation were detected in spleen and gonads at 16 dpi. Multifocal hepatic necrosis, heterophilic inflammation, and occasional basophilic intracytoplasmic inclusion bodies were observed at 20 dpi, along with ulcerative lymphocytic and heterophilic tracheitis and bronchitis. Tracheitis, bronchitis, and rare bone marrow necrosis were present at 24 dpi. Of the viscera tested for ranaviral DNA by PCR, the liver and spleen had the highest viral loads throughout infection, and thus appeared to be major targets of viral replication. Testing of whole blood by qPCR was the most-effective ante-mortem method for detecting ranaviral infection compared with oral swabs. This study represents the first time-dependent pathogenesis study of a ranaviral infection in turtles.
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Affiliation(s)
| | | | | | - Ellen Ariel
- James Cook University, Townsville, QLD, Australia
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