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Lv G, Wang J, Lian S, Wang H, Wu R. The Global Epidemiology of Bovine Leukemia Virus: Current Trends and Future Implications. Animals (Basel) 2024; 14:297. [PMID: 38254466 PMCID: PMC10812804 DOI: 10.3390/ani14020297] [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: 12/08/2023] [Revised: 01/02/2024] [Accepted: 01/11/2024] [Indexed: 01/24/2024] Open
Abstract
Bovine leukemia virus (BLV) is a retrovirus that causes enzootic bovine leucosis (EBL), which is the most significant neoplastic disease in cattle. Although EBL has been successfully eradicated in most European countries, infections continue to rise in Argentina, Brazil, Canada, Japan, and the United States. BLV imposes a substantial economic burden on the cattle industry, particularly in dairy farming, as it leads to a decline in animal production performance and increases the risk of disease. Moreover, trade restrictions on diseased animals and products between countries and regions further exacerbate the problem. Recent studies have also identified fragments of BLV nucleic acid in human breast cancer tissues, raising concerns for public health. Due to the absence of an effective vaccine, controlling the disease is challenging. Therefore, it is crucial to accurately detect and diagnose BLV at an early stage to control its spread and minimize economic losses. This review provides a comprehensive examination of BLV, encompassing its genomic structure, epidemiology, modes of transmission, clinical symptoms, detection methods, hazards, and control strategies. The aim is to provide strategic information for future BLV research.
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Affiliation(s)
- Guanxin Lv
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, China; (G.L.); (J.W.); (S.L.)
- Heilongjiang Provincial Key Laboratory of Prevention and Control of Bovine Diseases, Daqing 163319, China
- China Key Laboratory of Bovine Disease Control in Northeast China, Ministry of Agriculture and Rural Affairs, Daqing 163319, China
| | - Jianfa Wang
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, China; (G.L.); (J.W.); (S.L.)
- Heilongjiang Provincial Key Laboratory of Prevention and Control of Bovine Diseases, Daqing 163319, China
- China Key Laboratory of Bovine Disease Control in Northeast China, Ministry of Agriculture and Rural Affairs, Daqing 163319, China
| | - Shuai Lian
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, China; (G.L.); (J.W.); (S.L.)
- Heilongjiang Provincial Key Laboratory of Prevention and Control of Bovine Diseases, Daqing 163319, China
- China Key Laboratory of Bovine Disease Control in Northeast China, Ministry of Agriculture and Rural Affairs, Daqing 163319, China
| | - Hai Wang
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, China; (G.L.); (J.W.); (S.L.)
- Heilongjiang Provincial Key Laboratory of Prevention and Control of Bovine Diseases, Daqing 163319, China
- China Key Laboratory of Bovine Disease Control in Northeast China, Ministry of Agriculture and Rural Affairs, Daqing 163319, China
| | - Rui Wu
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, China; (G.L.); (J.W.); (S.L.)
- Heilongjiang Provincial Key Laboratory of Prevention and Control of Bovine Diseases, Daqing 163319, China
- China Key Laboratory of Bovine Disease Control in Northeast China, Ministry of Agriculture and Rural Affairs, Daqing 163319, China
- College of Biology and Agriculture, Jiamusi University, Jiamusi 154007, China
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Porta NG, Suarez-Archilla G, Miotti C, Molineri AI, Alvarez I, Trono K, Signorini M, Ruiz V. Seroprevalence and risk factors associated with bovine Leukemia virus infection in argentine beef cattle. Res Vet Sci 2023; 164:104999. [PMID: 37708828 DOI: 10.1016/j.rvsc.2023.104999] [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] [Received: 07/27/2023] [Revised: 08/29/2023] [Accepted: 08/30/2023] [Indexed: 09/16/2023]
Abstract
Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis, an endemic disease in dairy cattle of Argentina. However, little is known about the seroprevalence of BLV in beef cattle. In this study, we conducted a cross-sectional study including farms from thirteen provinces of Argentina. A total of 5827 bovine serum samples were collected from 76 farms and analyzed using an in-house developed enzyme-linked immunosorbent assay. Information about herd management was collected through a questionnaire, and univariate and multivariate analyses were performed to detect risk factors associated with BLV infection. Herd-level seroprevalence was 71.05%, while the mean animal-level seroprevalence was 7.23% (median = 2.69%; min = 0, max = 75). Only two provinces had no positive BLV samples. The other eleven provinces showed more than 50% of their farms infected with BLV. The multivariate model revealed that BLV prevalence was significantly associated with the use of animals raised in the same farm for cattle replacement (P = 0.005), breeding cows by natural mating with a bull (P < 0.001), and weaning calves after 6 months of age (P = 0.011). This extensive study revealed that BLV seroprevalence in Argentine beef farms has increased during the last years and allowed identifying some management practices associated with BLV prevalence. These data deserve special attention because BLV infection in beef cattle seems to lead to a dissemination pattern similar to that observed during the last decades in dairy cattle, especially considering that Argentina is the sixth beef producer in the world, with about 5% of global beef production.
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Affiliation(s)
- Natalia Gabriela Porta
- Laboratorio de Virus Adventicios, Instituto de Virología e Innovaciones Tecnológicas (IVIT), INTA-CONICET. Nicolás Repetto y De los Reseros (s/n), Hurlingham (CP1686), Buenos Aires, Argentina.
| | - Guillermo Suarez-Archilla
- Instituto de Investigación de la Cadena Láctea (IDICaL) INTA-CONICET. Estación Experimental Agropecuaria Rafaela, Ruta 34 Km 227, Rafaela, Santa Fe, Argentina.
| | - Camila Miotti
- Instituto de Investigación de la Cadena Láctea (IDICaL) INTA-CONICET. Estación Experimental Agropecuaria Rafaela, Ruta 34 Km 227, Rafaela, Santa Fe, Argentina.
| | - Ana Inés Molineri
- Instituto de Investigación de la Cadena Láctea (IDICaL) INTA-CONICET. Estación Experimental Agropecuaria Rafaela, Ruta 34 Km 227, Rafaela, Santa Fe, Argentina.
| | - Irene Alvarez
- Laboratorio de Virus Adventicios, Instituto de Virología e Innovaciones Tecnológicas (IVIT), INTA-CONICET. Nicolás Repetto y De los Reseros (s/n), Hurlingham (CP1686), Buenos Aires, Argentina
| | - Karina Trono
- Laboratorio de Virus Adventicios, Instituto de Virología e Innovaciones Tecnológicas (IVIT), INTA-CONICET. Nicolás Repetto y De los Reseros (s/n), Hurlingham (CP1686), Buenos Aires, Argentina.
| | - Marcelo Signorini
- Instituto de Investigación de la Cadena Láctea (IDICaL) INTA-CONICET. Estación Experimental Agropecuaria Rafaela, Ruta 34 Km 227, Rafaela, Santa Fe, Argentina.
| | - Vanesa Ruiz
- Laboratorio de Virus Adventicios, Instituto de Virología e Innovaciones Tecnológicas (IVIT), INTA-CONICET. Nicolás Repetto y De los Reseros (s/n), Hurlingham (CP1686), Buenos Aires, Argentina.
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Pichardo-Matamoros D, Sevilla F, Elizondo-Salazar J, Jiménez-Sánchez C, Roldan ERS, Soler C, Gacem S, Valverde A. Exploration of semen quality analyzed by casa-mot systems of brahman bulls infected with BLV and BHV-1. Sci Rep 2023; 13:18659. [PMID: 37907654 PMCID: PMC10618460 DOI: 10.1038/s41598-023-45981-9] [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: 07/19/2023] [Accepted: 10/26/2023] [Indexed: 11/02/2023] Open
Abstract
Enzootic bovine leukosis virus (BLV) and bovine herpesvirus 1 (BHV-1) are very important infectious agents for the livestock industry worldwide. The present study aimed to explore the association between natural exposure to BLV and BHV-1 with sperm quality analyzed by Computer-Assisted Semen Analysis (CASA) systems. Ten sexually mature Brahman bulls, with sanitary status BLV+/BHV-1+ (n = 2), BLV-/BHV-1+ (n = 6) and BLV-/BHV-1- (n = 2) were evaluated twice, 30 days apart. Results showed that sanitary status of each bull was not associated with semen quality. It was found that the quality of the semen from the second collection was better due to the interruption of sexual rest. The evidence thus revealed that a bull infected with BLV generated good-quality contaminated semen and, therefore, that it is essential to detect contaminated seminal samples to prevent the spread of BLV. A multivariate analysis showed the presence of four sperm subpopulations in Brahman bulls that differ significantly in their kinematic patterns and with respect to sanitary status (P < 0.05), indicating that infection-free and seronegative bulls present the best kinematic parameters, which improved discrimination of sperm quality according to sanitary status. Overall, the analyses indicate that the seropositive-infected bulls with BLV and BHV-1 should be excluded from beef cattle farms.
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Affiliation(s)
- Derling Pichardo-Matamoros
- National Agrarian University, Juigalpa Campus, Chontales, 55000, Nicaragua
- Graduate Program in Agricultural Sciences and Natural Resources, University of Costa Rica, 11501, San Pedro de Montes de Oca, Costa Rica
| | - Francisco Sevilla
- Animal Reproduction Laboratory, School of Agronomy, Costa Rica Institute of Technology, San Carlos Campus, Alajuela, 223-21002, Costa Rica
| | - Jorge Elizondo-Salazar
- Faculty of Agri-Food Sciences, Alfredo Volio Mata Experimental Station, University of Costa Rica, 30304, Cartago, Costa Rica
| | - Carlos Jiménez-Sánchez
- Tropical Diseases Research Program, Faculty of Health Sciences, Veterinary Medicine School, National University of Costa Rica, Benjamín Núñez Campus, 40101, Barreal de Heredia, Costa Rica
| | - Eduardo R S Roldan
- Department of Biodiversity and Evolutionary Biology, National Museum of Natural Sciences, Spanish National Research Council (CSIC), 28006, Madrid, Spain
| | - Carles Soler
- Department of Cellular Biology, Functional Biology and Physical Anthropology, University of Valencia, Campus Burjassot, C/Dr Moliner, 50, 46100, Valencia, Spain
| | - Sabrina Gacem
- Department of Cellular Biology, Functional Biology and Physical Anthropology, University of Valencia, Campus Burjassot, C/Dr Moliner, 50, 46100, Valencia, Spain
- Department of Animal Medicine and Surgery, Universitat Autònoma de Barcelona, Campus UAB, Edifici V, Bellaterra (Cerdanyola del Vallès), 08193, Barcelona, Spain
| | - Anthony Valverde
- Animal Reproduction Laboratory, School of Agronomy, Costa Rica Institute of Technology, San Carlos Campus, Alajuela, 223-21002, Costa Rica.
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Rahman MM, Ishikawa H, Yamauchi M, Takashima S, Kamatari YO, Shimizu K, Okada A, Inoshima Y. Characterization of mRNA Signature in Milk Small Extracellular Vesicles from Cattle Infected with Bovine Leukemia Virus. Pathogens 2023; 12:1239. [PMID: 37887755 PMCID: PMC10610248 DOI: 10.3390/pathogens12101239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 10/06/2023] [Accepted: 10/11/2023] [Indexed: 10/28/2023] Open
Abstract
This study aimed to characterize the mRNA signature of milk small extracellular vesicles (sEVs) from BLV-infected cattle. A total of 23 mRNAs, which showed greater abundance in milk sEVs from BLV-infected cattle compared to those from BLV-uninfected (control) cattle, were identified through microarray analyses conducted in our previous study. To assess the significance of these differences in mRNA abundance, milk was collected from six control cattle and twenty-six cattle infected with BLV. The infected cattle were categorized into two distinct groups based on their proviral loads: a group of eight cattle with low proviral loads (LPVL), characterized by <10,000 copies per 105 white blood cells (WBC), and a group of eighteen cattle with high proviral loads (HPVL), marked by ≥10,000 copies per 105 WBC. The qPCR analysis quantified 7 out of 23 mRNAs, including BoLA, CALB1, IL33, ITGB2, MYOF, TGFBR1, and TMEM156, in the milk sEVs from control cattle, LPVL cattle, and HPVL cattle. Significantly, the average relative expression of CALB1 mRNA in milk sEVs was higher in LPVL cattle compared to HPVL cattle and control cattle (p < 0.05), while it was relatively lower in HPVL cattle compared to LPVL cattle and control cattle (p > 0.05). Likewise, the average relative expression of TMEM156 mRNA in milk sEVs was significantly higher in LPVL cattle compared to HPVL cattle (p < 0.05), and relatively lower in HPVL cattle compared to LPVL cattle and control cattle (p > 0.05). The results indicate distinct patterns of CALB1 and TMEM156 mRNA levels in milk sEVs, with higher levels observed in LPVL cattle and lower levels in HPVL cattle. The current study could provide essential information to comprehend the complexities during the progression of BLV infection and direct the exploration of mRNA biomarkers for monitoring the clinical stage of BLV infection.
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Affiliation(s)
- Md. Matiur Rahman
- Laboratory of Food and Environmental Hygiene, Cooperative Department of Veterinary Medicine, Gifu University, Gifu 501-1112, Japan
- Department of Medicine, Faculty of Veterinary, Animal and Biomedical Sciences, Sylhet Agricultural University, Sylhet 3100, Bangladesh
| | - Hinata Ishikawa
- Laboratory of Food and Environmental Hygiene, Cooperative Department of Veterinary Medicine, Gifu University, Gifu 501-1112, Japan
| | - Marika Yamauchi
- Laboratory of Food and Environmental Hygiene, Cooperative Department of Veterinary Medicine, Gifu University, Gifu 501-1112, Japan
| | - Shigeo Takashima
- Division of Genomics Research, Life Science Research Center, Gifu University, Gifu 501-1112, Japan
- Institute for Glyco-Core Research (iGCORE), Gifu University, Gifu 501-1112, Japan
- The United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu 501-1112, Japan
| | - Yuji O. Kamatari
- Institute for Glyco-Core Research (iGCORE), Gifu University, Gifu 501-1112, Japan
- The United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu 501-1112, Japan
- Division of Instrumental Analysis, Life Science Research Center, Gifu University, Gifu 501-1112, Japan
| | - Kaori Shimizu
- Laboratory of Food and Environmental Hygiene, Cooperative Department of Veterinary Medicine, Gifu University, Gifu 501-1112, Japan
| | - Ayaka Okada
- Laboratory of Food and Environmental Hygiene, Cooperative Department of Veterinary Medicine, Gifu University, Gifu 501-1112, Japan
- Education and Research Center for Food Animal Health, Gifu University (GeFAH), Gifu 501-1112, Japan
| | - Yasuo Inoshima
- Laboratory of Food and Environmental Hygiene, Cooperative Department of Veterinary Medicine, Gifu University, Gifu 501-1112, Japan
- Education and Research Center for Food Animal Health, Gifu University (GeFAH), Gifu 501-1112, Japan
- Joint Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1112, Japan
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Assessment of Natural Transmission of Bovine Leukemia Virus in Dairies from Southern Chile. Animals (Basel) 2022; 12:ani12131734. [PMID: 35804632 PMCID: PMC9264828 DOI: 10.3390/ani12131734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/29/2022] [Accepted: 07/04/2022] [Indexed: 11/17/2022] Open
Abstract
Simple Summary A longitudinal study was conducted to describe the frequency and epidemiological association of risk management practices related to new cases of BLV in cattle on dairy farms in Southern Chile. Animal information was obtained from the records of each farm, as well as blood and milk samples that, tested by commercial blocking ELISA to assess the infection status of animals. A higher number of new cases was found in adult animals that were related to practices, such as rectal palpation, artificial insemination, and injections. However, it is important to carry out other studies that establish the role of management practices in the spreading of BLV to improve the control of disease. Abstract Bovine leukemia virus (BLV) is a retrovirus that affects cattle worldwide. A longitudinal study was conducted with the aim to (a) estimate the incidence rate of the BLV infection of dairy farms in the regions of Los Ríos and Los Lagos (Chile), and (b) describe the frequency and epidemiological association of risk management practices related to new cases in cattle on dairy farms in Southern Chile. Infection status was based on commercial blocking ELISA results, on serum and milk. Individual information on animals and management practices was extracted from farm records, and then the most likely date of infection for new cases was estimated. The number of new infections was used to calculate the within-herd incidence rate. Adult animals had an incidence rate of 1.16 (95% CI 0.96; 1.20) cases per 100 cow-months at risk, while for young animals it was 0.64 (95% CI 0.44; 1.00) cases per 100 animal-months at risk. Rectal palpation, artificial insemination, and injections were the most common practices related to infection. Further studies are needed to determine if these are the only practices that facilitate spreading or if there are other practices that can be handled better in order to reduce the spread of BLV.
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Kuczewski A, Adams C, Lashewicz B, van der Meer F. Alberta dairy farmers’ and veterinarians’ opinion about bovine leukemia virus control measures. Prev Vet Med 2022; 200:105590. [DOI: 10.1016/j.prevetmed.2022.105590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 12/22/2021] [Accepted: 01/23/2022] [Indexed: 11/30/2022]
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Potential Risk Factors Associated with Infection with Bovine Leukaemia Virus in Dairy and Beef Cattle in Taiwan. Pathogens 2021; 10:pathogens10121553. [PMID: 34959508 PMCID: PMC8707763 DOI: 10.3390/pathogens10121553] [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: 09/22/2021] [Revised: 11/23/2021] [Accepted: 11/26/2021] [Indexed: 11/24/2022] Open
Abstract
Bovine leukaemia virus (BLV), which is classified as a Deltaretrovirus, is the aetiologic agent of enzootic bovine leukosis (EBL), a chronic lymphoproliferative disorder with a worldwide distribution. EBL is widespread in dairy herds and causes a direct economic impact due to reduced milk production and the early culling of BLV-infected cattle. The BLV infection status in Taiwan remains largely unknown; a high prevalence of BLV in dairy cows was recently revealed. The present study further investigated BLV infections in beef cattle. Surprisingly, the prevalence of BLV proviral DNA was as low as 11.8% (23/195), which is significantly lower than that noted in dairy cows, which was 42.5% (102/240) (p < 0.001). Factors associated with BLV infections were subsequently investigated. Due to the differences in herd management, an analysis of risk factors for a BLV infection was independently conducted in these two sectors. Several factors associated with a BLV infection were identified. Age was significantly associated with BLV infection status in dairy cows (p < 0.001) but not in beef cattle. A high prevalence of BLV was observed in cattle >15.5 months old (57.8%) compared with those ≤15.5 months old (11.4%). Moreover, after stratification analysis, based on the critical age of 15.5 months, as determined by the receiver operating characteristic (ROC) curve, a significantly higher BLV prevalence was demonstrated in lactating dairy cows, cattle undergoing bull breeding, heifers at older ages, and those undergoing routine rectal palpation. Due to the high prevalence of BLV in Taiwan, the development of an effective control program, based on the identified risk factors, is important for interrupting the routes of BLV transmission within herds.
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Marawan MA, Alouffi A, El Tokhy S, Badawy S, Shirani I, Dawood A, Guo A, Almutairi MM, Alshammari FA, Selim A. Bovine Leukaemia Virus: Current Epidemiological Circumstance and Future Prospective. Viruses 2021; 13:v13112167. [PMID: 34834973 PMCID: PMC8618541 DOI: 10.3390/v13112167] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 10/23/2021] [Accepted: 10/24/2021] [Indexed: 11/23/2022] Open
Abstract
Bovine leukaemia virus (BLV) is a deltaretrovirus that is closely related to human T-cell leukaemia virus types 1 and 2 (HTLV-1 and -2). It causes enzootic bovine leukosis (EBL), which is the most important neoplastic disease in cattle. Most BLV-infected cattle are asymptomatic, which potentiates extremely high shedding rates of the virus in many cattle populations. Approximately 30% of them show persistent lymphocytosis that has various clinical outcomes; only a small proportion of animals (less than 5%) exhibit signs of EBL. BLV causes major economic losses in the cattle industry, especially in dairy farms. Direct costs are due to a decrease in animal productivity and in cow longevity; indirect costs are caused by restrictions that are placed on the import of animals and animal products from infected areas. Most European regions have implemented an efficient eradication programme, yet BLV prevalence remains high worldwide. Control of the disease is not feasible because there is no effective vaccine against it. Therefore, detection and early diagnosis of the disease are essential in order to diminish its spreading and the economic losses it causes. This review comprises an overview of bovine leukosis, which highlights the epidemiology of the disease, diagnostic tests that are used and effective control strategies.
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Affiliation(s)
- Marawan A. Marawan
- The State Key Laboratory of Agricultural Microbiology, Huazhong Agriculture University, Wuhan 430070, China; (I.S.); (A.D.)
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- Department of Animal Medicine (Infectious Diseases), Faculty of Veterinary Medicine, Benha University, Toukh 13736, Egypt;
- Correspondence: (M.A.M.); (A.G.); (A.S.)
| | - Abdulaziz Alouffi
- King Abdulaziz City for Science and Technology, Riyadh 12354, Saudi Arabia;
- The Chair of Vaccines Research for Infectious Diseases, King Saud University, Riyadh 11495, Saudi Arabia;
| | - Suleiman El Tokhy
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Tanta University, Tanta 31111, Egypt;
| | - Sara Badawy
- Department of Pathology, Faculty of Veterinary Medicine, Benha University, Toukh 13736, Egypt;
- Natural Reference Laboratory of Veterinary Drug Residues (HZAU), MAO Key Laboratory for Detection of Veterinary Drug Residues Huazhong Agricultural University, Wuhan 430070, China
| | - Ihsanullah Shirani
- The State Key Laboratory of Agricultural Microbiology, Huazhong Agriculture University, Wuhan 430070, China; (I.S.); (A.D.)
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- Para-Clinic Department, Faculty of Veterinary Medicine, Jalalabad 2601, Afghanistan
| | - Ali Dawood
- The State Key Laboratory of Agricultural Microbiology, Huazhong Agriculture University, Wuhan 430070, China; (I.S.); (A.D.)
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- Infectious Diseases, Medicine Department, Faculty of Veterinary Medicine, University of Sadat City, Sadat City 32897, Egypt
| | - Aizhen Guo
- The State Key Laboratory of Agricultural Microbiology, Huazhong Agriculture University, Wuhan 430070, China; (I.S.); (A.D.)
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, Huazhong Agricultural University, Wuhan 430070, China
- Correspondence: (M.A.M.); (A.G.); (A.S.)
| | - Mashal M. Almutairi
- The Chair of Vaccines Research for Infectious Diseases, King Saud University, Riyadh 11495, Saudi Arabia;
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh 22334, Saudi Arabia
| | - Fahdah Ayed Alshammari
- College of Sciences and Literature Microbiology, Nothern Border University, Arar 73211, Saudi Arabia;
| | - Abdelfattah Selim
- Department of Animal Medicine (Infectious Diseases), Faculty of Veterinary Medicine, Benha University, Toukh 13736, Egypt;
- Correspondence: (M.A.M.); (A.G.); (A.S.)
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Borjigin L, Yoneyama S, Saito S, Polat M, Inokuma M, Shinozaki Y, Tanaka N, Yamanaka R, Yasui A, Mimura M, Murakami H, Takeshima SN, Aida Y. A novel real time PCR assay for bovine leukemia virus detection using mixed probes and degenerate primers targeting novel BLV strains. J Virol Methods 2021; 297:114264. [PMID: 34411645 DOI: 10.1016/j.jviromet.2021.114264] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 08/12/2021] [Accepted: 08/12/2021] [Indexed: 01/10/2023]
Abstract
The bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis, the most common neoplastic disease in cattle. We previously developed the quantitative real-time PCR (qPCR) assay to measure the proviral loads of BLV using coordination of common motif (CoCoMo) degenerate primers. We here found four single mutations within the probe region of the original BLV-CoCoMo-qPCR assay, three of which have negative impact on its sensitivity in the probe sequences of the long terminal regions of the BLV-CoCoMo-qPCR-2 assay, using genomic DNA from 887 cows from 27 BLV-positive farms via a nationwide survey conducted in 2011 and 2017 in Japan. Therefore, the modified probes were designed to completely match the three BLV mutant strains identified here. Moreover, we examined the optimum ratio of the concentration to be mixed with the wild type and three new BLV TaqMan probes were designed here using genomic DNAs extracted from cattle naturally infected with the wild type BLV strain and three mutant strains. Finally, we successfully established an improved assay maintained the original sensitivity and reproducibility and can detect novel BLV strains.
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Affiliation(s)
- Liushiqi Borjigin
- Viral Infectious Diseases Unit, RIKEN, Wako, Saitama, 351-0198, Japan
| | - Shuji Yoneyama
- Central Livestock Hygiene Service Center of Tochigi Prefecture, Utsunomiya, Tochigi, 321-0905, Japan
| | - Susumu Saito
- Viral Infectious Diseases Unit, RIKEN, Wako, Saitama, 351-0198, Japan
| | - Meripet Polat
- Viral Infectious Diseases Unit, RIKEN, Wako, Saitama, 351-0198, Japan
| | - Michihito Inokuma
- Chuo Livestock Hygiene Service Center of Chiba Prefecture, Chiba, Chiba, 262-0011, Japan
| | - Yasuo Shinozaki
- Nanbu Livestock Hygiene Service Center of Chiba Prefecture, Kamogawa, Chiba, 296-0033, Japan
| | - Naoko Tanaka
- Nanbu Livestock Hygiene Service Center of Chiba Prefecture, Kamogawa, Chiba, 296-0033, Japan
| | - Risa Yamanaka
- Kumagaya Livestock Hygiene Service Center of Saitama Prefecture, Kumagaya, Saitama, 360-0813, Japan
| | - Anna Yasui
- Kumagaya Livestock Hygiene Service Center of Saitama Prefecture, Kumagaya, Saitama, 360-0813, Japan
| | - Munehito Mimura
- Kumagaya Livestock Hygiene Service Center of Saitama Prefecture, Kumagaya, Saitama, 360-0813, Japan
| | - Hironobu Murakami
- Laboratory of Animal Health Ⅱ, School of Veterinary Medicine, Azabu University, Sagamihara, Kanagawa, 252-5201, Japan
| | - Shin-Nosuke Takeshima
- Department of Food and Nutrition, Jumonji University, Niiza, Saitama, 352-8510, Japan
| | - Yoko Aida
- Viral Infectious Diseases Unit, RIKEN, Wako, Saitama, 351-0198, Japan; Laboratory of Global Infectious Diseases Control Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, 113-8657, Japan.
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Sakhawat A, Rola-Łuszczak M, Osiński Z, Bibi N, Kuźmak J. Bayesian Estimation of the True Seroprevalence and Risk Factor Analysis of Bovine Leukemia Virus Infection in Pakistan. Animals (Basel) 2021; 11:ani11051404. [PMID: 34069156 PMCID: PMC8156210 DOI: 10.3390/ani11051404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 05/07/2021] [Accepted: 05/07/2021] [Indexed: 12/03/2022] Open
Abstract
Simple Summary The enzootic bovine leucosis is the most common and economically important viral disease of cattle, caused by bovine leukemia virus (BLV). In cattle, infection with BLV leads to decreased milk production and premature culling and also impairs the immune system predisposing animals to other infections and increasing severity of disease. The aim of this study was to estimate the true seropositivity to BLV at the farm and within-farm levels in Pakistan, using a latent class analysis. In addition, some factors influencing BLV seropositivity were analyzed. We tested 1380 dairy cattle from 451 herds and 92 water buffalo. Analysis at the within-herd and herd levels showed 3.8% of cattle and 1.4% of herds were truly seropositive. All 92 serum samples from water buffalo were negative. The study demonstrated strong association between BLV seroprevalence and herd size but not with common housing of cattle representing indigenous breeds with exotic breed or their crossbred and also common housing of cattle and water buffalo. Abstract The objective of this study was to determine the true seroprevalence of bovine leukemia virus (BLV) infection in dairy cattle from Pakistan at the animal and herd-level. We tested 1380 dairy cattle from 451 herds and 92 water buffalo. The sera were tested by ELISA and the results were analyzed using Bayesian inference. The median posterior estimate of the herd level true BLV prevalence was 1.4%, with a 95% credible interval (CI) 0.7–3.1, whereas the median posterior estimate of the within-farm true seroprevalence was 3.8% with a 95% CI 2.8–4.8. All 92 sera collected from water buffalo were negative. Several risk factors potentially associated with seropositivity to BLV infections in Pakistan were analyzed using logistic regression model based on calculation of an odds ratio (OR). The study showed an association between seropositivity and medium herd (≥50) size (OR = 23.57, 95% CI: 3.01–103.48). Common housing of indigenous cattle with exotic-breed cattle (OR = 0.67, 95% CI: 06–2.35) or housing indigenous or their crossbred cattle with exotic-breed cattle (OR = 0.95, 95% CI: 0.14–3.01) had no effect on the BLV seroprevalence. Similarly, common housing of cattle and water buffalo was not risk factor for increased BLV seropositivity (OR = 27.10, 95% CI: 0.63–119.34).
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Affiliation(s)
- Ali Sakhawat
- National Veterinary Laboratories, Islamabad 45500, Pakistan;
- Animal Quarantine Department, Ministry of National Food Security and Research, Peshawar 25000, Pakistan
- Department of Bio Sciences, COMSATS University, Islamabad 45500, Pakistan;
| | - Marzena Rola-Łuszczak
- National Veterinary Research Institute, 24-100 Puławy, Poland; (Z.O.); (J.K.)
- Correspondence:
| | - Zbigniew Osiński
- National Veterinary Research Institute, 24-100 Puławy, Poland; (Z.O.); (J.K.)
| | - Nazia Bibi
- Department of Bio Sciences, COMSATS University, Islamabad 45500, Pakistan;
| | - Jacek Kuźmak
- National Veterinary Research Institute, 24-100 Puławy, Poland; (Z.O.); (J.K.)
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11
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Kuczewski A, Orsel K, Barkema HW, Mason S, Erskine R, van der Meer F. Invited review: Bovine leukemia virus-Transmission, control, and eradication. J Dairy Sci 2021; 104:6358-6375. [PMID: 33741150 DOI: 10.3168/jds.2020-18925] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 11/21/2020] [Indexed: 11/19/2022]
Abstract
Bovine leukemia virus (BLV) infection, endemic in North American dairy herds, has production-limiting effects. A literature review of available papers published since 1995 concerning BLV transmission and its control was conducted. Although confirmed transmission routes were reviewed (blood, natural breeding, in utero, colostrum, and milk), there is still a lack of detailed information on other specific risks for transmission (e.g., contact transmission and hoof-trimming knives). Eradication of BLV has been achieved by combined management, segregation, and culling approaches. In contrast, although sole implementation of best management practices aimed at prevention of BLV transmission has decreased within-herd BLV prevalence, it has not eradicated BLV from a herd. Therefore, control and eradication of BLV by best management practices only should be further investigated. Additionally, the role of proviral load in infected cattle was investigated. Cattle with a high proviral load seem to be more likely to infect others, whereas those with a very low proviral load seem to have low risks of transmitting BLV. Information on proviral load could be taken into account when controlling BLV in high-prevalence herds. In conclusion, there is a need for detailed, large-scale studies investigating roles of specific transmission routes, knowing proviral load of infected individuals.
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Affiliation(s)
- Alessa Kuczewski
- Department of Ecosystem and Public Health, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Karin Orsel
- Department of Production Animal Health, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Herman W Barkema
- Department of Production Animal Health, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Steve Mason
- Agromedia International Inc., Calgary, AB T2L 0T6, Canada
| | - Ron Erskine
- Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48824
| | - Frank van der Meer
- Department of Ecosystem and Public Health, University of Calgary, Calgary, AB T2N 4Z6, Canada.
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12
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Kuczewski A, Mason S, Orsel K, van der Meer F. Pilot implementation of a newly developed bovine leukemia virus control program on 11 Alberta dairy farms. J Dairy Sci 2021; 104:4549-4560. [PMID: 33663863 DOI: 10.3168/jds.2020-19251] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 11/03/2020] [Indexed: 11/19/2022]
Abstract
We developed a custom bovine leukemia virus (BLV) control program for the Alberta dairy industry, consisting of a risk assessment and a comprehensive list of best management practices (BMP) aimed at prevention of BLV transmission between cattle. This control program was implemented on 11 farms for approximately 1 yr. Blood samples were collected from all cattle ≥12 mo old, and serum was tested with a commercial ELISA. Risk assessments were performed on each farm, risk-connected on-farm management was identified, and management changes expected to prevent transmission of BLV between cattle were suggested by the first author and agreed upon with each farmer. Throughout the following year, all participating farmers were visited multiple times to identify and overcome barriers to implementation and to monitor progress. After approximately 1 yr of implementing BLV control, all cattle ≥12 mo old on farm with a negative or no previous test result were sampled, and the within-herd prevalence was determined. The median number of cattle on farm that were ≥12 mo was 195 (range 110-524). The initial prevalence averaged 39% (13-66%). On average, 5 BMP (3-7) were suggested to each farmer. On average, 4 BMP (1-7) were implemented. At the second sampling, the average within-herd prevalence of all animals that tested positive (including the previous sampling) was 36% (12-62%). Eight farms reduced their within-herd BLV prevalence, within-herd prevalence stayed constant on 1 farm, and it increased on 1 farm. The remaining farm terminated their participation before the second sampling. The number of seroconversions per farm ranged from 3 to 109, highlighting the success of some producers to minimize new infections. The risk assessment was proven to be a valuable tool to identify flaws in on-farm management, although risk assessment score was unrelated to the within-herd BLV prevalence. Finally, it appeared that implementation of BMP aimed at prevention of BLV transmission between cattle could reduce within-herd BLV prevalence when farmers committed to their implementation.
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Affiliation(s)
- Alessa Kuczewski
- Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Steve Mason
- Agromedia International Inc., Calgary, AB T2L 0T6, Canada; Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Karin Orsel
- Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada
| | - Frank van der Meer
- Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada.
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13
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Bartlett PC, Ruggiero VJ, Hutchinson HC, Droscha CJ, Norby B, Sporer KRB, Taxis TM. Current Developments in the Epidemiology and Control of Enzootic Bovine Leukosis as Caused by Bovine Leukemia Virus. Pathogens 2020; 9:E1058. [PMID: 33352855 PMCID: PMC7766781 DOI: 10.3390/pathogens9121058] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 01/29/2023] Open
Abstract
Enzootic Bovine Leukosis (EBL) caused by the bovine leukemia virus (BLV) has been eradicated in over 20 countries. In contrast, the U.S. and many other nations are experiencing increasing prevalence in the absence of efforts to control transmission. Recent studies have shown that BLV infection in dairy cattle has a greater impact beyond the long-recognized lymphoma development that occurs in <5% of infected cattle. Like other retroviruses, BLV appears to cause multiple immune system disruptions, affecting both cellular and humoral immunity, which are likely responsible for increasingly documented associations with decreased dairy production and decreased productive lifespan. Realization of these economic losses has increased interest in controlling BLV using technology that was unavailable decades ago, when many nations eradicated BLV via traditional antibody testing and slaughter methods. This traditional control is not economically feasible for many nations where the average herd antibody prevalence is rapidly approaching 50%. The ELISA screening of cattle with follow-up testing via qPCR for proviral load helps prioritize the most infectious cattle for segregation or culling. The efficacy of this approach has been demonstrated in at least four herds. Breeding cattle for resistance to BLV disease progression also appears to hold promise, and several laboratories are working on BLV vaccines. There are many research priorities for a wide variety of disciplines, especially including the need to investigate the reports linking BLV and human breast cancer.
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Affiliation(s)
- Paul C. Bartlett
- College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA; (V.J.R.); (B.N.)
| | - Vickie J. Ruggiero
- College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA; (V.J.R.); (B.N.)
| | | | - Casey J. Droscha
- CentralStar Cooperative, East Lansing, MI 48910, USA; (C.J.D.); (K.R.B.S.)
| | - Bo Norby
- College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA; (V.J.R.); (B.N.)
| | - Kelly R. B. Sporer
- CentralStar Cooperative, East Lansing, MI 48910, USA; (C.J.D.); (K.R.B.S.)
| | - Tasia M. Taxis
- Department of Animal Science, Michigan State University, East Lansing, MI 48824, USA;
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14
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Benitez OJ, Norby B, Bartlett PC, Maeroff JE, Grooms DL. Impact of bovine leukemia virus infection on beef cow longevity. Prev Vet Med 2020; 181:105055. [PMID: 32593082 DOI: 10.1016/j.prevetmed.2020.105055] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 05/25/2020] [Accepted: 06/07/2020] [Indexed: 11/19/2022]
Abstract
Bovine leukosis is a chronic lymphoproliferative disorder caused by bovine leukemia virus (BLV). Previous studies estimate that 38 % of cow-calf beef herds and 10.3 % of individual beef cows in the US are BLV seropositive. About 70 % of BLV infected animals are asymptomatic carriers of the virus, while less than 5% develop lymphosarcoma, the leading reason for carcass condemnation at the US slaughterhouses. Studies provide evidence that BLV infection leads to decreased immune function making animals more vulnerable to other diseases, which could shorten their productive lifespan and increase economic losses in the cattle industry. BLV seropositive dairy cows are reportedly more likely to be culled sooner compared with their uninfected herd mates. Beyond simple prevalence studies, little is known about the impact of BLV infection in beef cattle production or specifically on beef cow longevity. Our objective was to determine the association between BLV infection and cow longevity in beef cow-calf operations. Twenty-seven cow-calf herds from the Upper Midwest volunteered to participate in this study. Female beef cattle (n = 3146) were tested for serum BLV antibodies by ELISA. A subsample of 648 cows were also tested for BLV proviral load (PVL). Culling data was collected for the subsequent 24 months. Twenty-one herds (77.7 %) had at least one BLV-infected animal, and 29.2 % (930/3146) of tested animals were BLV seropositive. Of the BLV-positive cows, 33.7 % (318/943) were culled compared with 32.1 % (541/1682) of the seronegative cows. BLV status did not affect cows' longevity within herds (P = 0.062). However, cows with high BLV PVL had decreased survival within the herd compared with ELISA- negative cows (P = 0.01). Overall, infection with BLV did not impact beef cow longevity unless the disease had progressed to a point of high BLV PVL.
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Affiliation(s)
- Oscar J Benitez
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Rd, East Lansing, MI 48895, United States.
| | - Bo Norby
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Rd, East Lansing, MI 48895, United States
| | - Paul C Bartlett
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Rd, East Lansing, MI 48895, United States
| | - Jacqueline E Maeroff
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Rd, East Lansing, MI 48895, United States
| | - Daniel L Grooms
- College of Veterinary Medicine, Iowa State University, 1800 Christensen Drive, Ames, Iowa 50014, United States
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15
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Watanuki S, Takeshima SN, Borjigin L, Sato H, Bai L, Murakami H, Sato R, Ishizaki H, Matsumoto Y, Aida Y. Visualizing bovine leukemia virus (BLV)-infected cells and measuring BLV proviral loads in the milk of BLV seropositive dams. Vet Res 2019; 50:102. [PMID: 31783914 PMCID: PMC6884895 DOI: 10.1186/s13567-019-0724-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 11/14/2019] [Indexed: 12/02/2022] Open
Abstract
Bovine leukemia virus (BLV) infects cattle and causes serious problems for the cattle industry, worldwide. Vertical transmission of BLV occurs via in utero infection and ingestion of infected milk and colostrum. The aim of this study was to clarify whether milk is a risk factor in BLV transmission by quantifying proviral loads in milk and visualizing the infectivity of milk. We collected blood and milk from 48 dams (46 BLV seropositive dams and 2 seronegative dams) from seven farms in Japan and detected the BLV provirus in 43 blood samples (89.6%) but only 22 milk samples (45.8%) using BLV-CoCoMo-qPCR-2. Although the proviral loads in the milk tended to be lower, a positive correlation was firstly found between the proviral loads with blood and milk. Furthermore, the infectivity of milk cells with BLV was visualized ex vivo using a luminescence syncytium induction assay (LuSIA) based on CC81-GREMG cells, which form syncytia expressing enhanced green fluorescent protein (EGFP) in response to BLV Tax and Env expressions when co-cultured with BLV-infected cells. Interestingly, in addition to one BLV-infected dam with lymphoma, syncytia with EGFP fluorescence were observed in milk cells from six BLV-infected, but healthy, dams by an improved LuSIA, which was optimized for milk cells. This is the first report demonstrating the infectious capacity of cells in milk from BLV-infected dams by visualization of BLV infection ex vivo. Thus, our results suggest that milk is a potential risk factor for BLV vertical spread through cell to cell transmission.
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Affiliation(s)
- Sonoko Watanuki
- Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.,Laboratory of Global Animal Resource Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Shin-Nosuke Takeshima
- Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.,Photonics Control Technology Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.,Department of Food and Nutrition, Jumonji University, Niiza, Saitama, 352-8510, Japan
| | - Liushiqi Borjigin
- Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.,Nakamura Laboratory, Baton Zone Program, RIKEN Cluster for Science, Technology and Innovation Hub, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Hirotaka Sato
- Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.,Nakamura Laboratory, Baton Zone Program, RIKEN Cluster for Science, Technology and Innovation Hub, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Lanlan Bai
- Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.,Photonics Control Technology Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Hironobu Murakami
- Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.,Laboratory of Animal Health II, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa, 252-5201, Japan
| | - Reiichiro Sato
- Laboratory of Farm Animal Internal Medicine, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa, 252-5201, Japan
| | - Hiroshi Ishizaki
- Grazing Animal Unit and Nasu Operation Unit, Institute of Livestock and Grassland Science, NARO, 768 Senbonmatsu, Nasushiobara, Tochigi, 329-2793, Japan
| | - Yasunobu Matsumoto
- Laboratory of Global Animal Resource Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Yoko Aida
- Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan. .,Laboratory of Global Animal Resource Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan. .,Nakamura Laboratory, Baton Zone Program, RIKEN Cluster for Science, Technology and Innovation Hub, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
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