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Bessière P, Hayes B, Filaire F, Lèbre L, Vergne T, Pinson M, Croville G, Guérin JL. Optimizing environmental viral surveillance: bovine serum albumin increases RT-qPCR sensitivity for high pathogenicity avian influenza H5Nx virus detection from dust samples. Microbiol Spectr 2023; 11:e0305523. [PMID: 37982626 PMCID: PMC10715206 DOI: 10.1128/spectrum.03055-23] [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: 08/08/2023] [Accepted: 10/15/2023] [Indexed: 11/21/2023] Open
Abstract
IMPORTANCE With the circulation of high pathogenicity avian influenza viruses having intensified considerably in recent years, the European Union is considering the vaccination of farmed birds. A prerequisite for this vaccination is the implementation of drastic surveillance protocols. Environmental sampling is a relevant alternative to animal sampling. However, environmental samples often contain inhibitory compounds in large enough quantities to inhibit RT-qPCR reactions. As bovine serum albumin is a molecule used in many fields to overcome this inhibitory effect, we tested its use on dust samples from poultry farms in areas heavily affected by HPAIV epizootics. Our results show that its use significantly increases the sensitivity of the method.
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Affiliation(s)
| | - Brandon Hayes
- IHAP, Université de Toulouse, INRAE, ENVT, Toulouse, France
| | - Fabien Filaire
- IHAP, Université de Toulouse, INRAE, ENVT, Toulouse, France
- THESEO France, LanXess Biosecurity, LanXess Group, Laval, France
| | - Laetitia Lèbre
- IHAP, Université de Toulouse, INRAE, ENVT, Toulouse, France
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2
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Wu S, Ding T, Shao H, Qian K, Ye J, Qin A. A quadruplex real-time PCR assay combined with a conventional PCR for the differential detection of Marek's disease virus vaccines and field strains. Front Vet Sci 2023; 10:1161441. [PMID: 37252401 PMCID: PMC10213282 DOI: 10.3389/fvets.2023.1161441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 04/10/2023] [Indexed: 05/31/2023] Open
Abstract
To evaluate the effect of the vaccine and differentiate vaccine from virulent MDV, a new quadruplex real-time PCR assay based on TaqMan probes was developed to differentiate and accurately quantify HVT, CVI988 and virulent MDV-1. The results showed that the limit of detection (LOD) of the new assay was 10 copies with correlation coefficients >0.994 of CVI988, HVT and virulent MDV DNA molecules without cross-reactivity with other avian disease viruses. The intra-assay and inter-assay coefficients of variation (CVs) of Ct values for the new assay were less than 3%. Analysis of replication kinetics of CVI988 and virulent MDV of collected feathers between 7 and 60 days post-infection (dpi) showed MD5 had no significant effect on the genomic load of CVI988 (p > 0.05), while vaccination with CVI988 could significantly reduce the viral load of MD5 (p < 0.05). Combined with meq gene PCR, this method can effectively identify virulent MDV infections in immunized chickens. These results demonstrated that this assay could distinguish between the vaccine and virulent MDV strains and had the advantages of being reliable, sensitive and specific to confirm the immunization status and monitor the circulation of virulent MDV strains.
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Affiliation(s)
- Shaopeng Wu
- Ministry of Education Key Laboratory for Avian Preventive Medicine, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, Jiangsu, China
| | - Tian Ding
- Ministry of Education Key Laboratory for Avian Preventive Medicine, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, Jiangsu, China
| | - Hongxia Shao
- Ministry of Education Key Laboratory for Avian Preventive Medicine, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, Jiangsu, China
| | - Kun Qian
- Ministry of Education Key Laboratory for Avian Preventive Medicine, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, Jiangsu, China
| | - Jianqiang Ye
- Ministry of Education Key Laboratory for Avian Preventive Medicine, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, Jiangsu, China
| | - Aijian Qin
- Ministry of Education Key Laboratory for Avian Preventive Medicine, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, Jiangsu, China
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Viet Thu HT, Trang HN, Phuoc Chien NT, Ngu NT, Hien ND. Occurrence of Marek's Disease in Backyard Chicken Flocks in Vietnam. Avian Dis 2022; 66:230-236. [DOI: 10.1637/aviandiseases-d-22-00009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 04/08/2022] [Indexed: 11/05/2022]
Affiliation(s)
- Ho Thi Viet Thu
- Can Tho University, Campus II, Area II, 3/2 Street, Xuan-Khanh Ward, Ninh-Kieu District, Can Tho City, Vietnam
| | - Huynh Ngoc Trang
- Can Tho University, Campus II, Area II, 3/2 Street, Xuan-Khanh Ward, Ninh-Kieu District, Can Tho City, Vietnam
| | - Nguyen Tran Phuoc Chien
- Can Tho University, Campus II, Area II, 3/2 Street, Xuan-Khanh Ward, Ninh-Kieu District, Can Tho City, Vietnam
| | - Nguyen Trong Ngu
- Can Tho University, Campus II, Area II, 3/2 Street, Xuan-Khanh Ward, Ninh-Kieu District, Can Tho City, Vietnam
| | - Nguyen Duc Hien
- Can Tho University, Campus II, Area II, 3/2 Street, Xuan-Khanh Ward, Ninh-Kieu District, Can Tho City, Vietnam
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Mescolini G, Baigent SJ, Catelli E, Nair VK. Rapid, Sensitive, and Species-Specific Detection of Conventional and Recombinant Herpesvirus of Turkeys Vaccines Using Loop-Mediated Isothermal Amplification Coupled With a Lateral Flow Device Readout. Front Vet Sci 2022; 9:873163. [PMID: 35812862 PMCID: PMC9260039 DOI: 10.3389/fvets.2022.873163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 04/19/2022] [Indexed: 11/23/2022] Open
Abstract
Marek's disease, an economically important disease of chickens caused by virulent serotype 1 strains of the Mardivirus Marek's disease virus (MDV-1), is effectively controlled in the field by live attenuated vaccine viruses including herpesvirus of turkeys (HVT)—both conventional HVT (strain FC126) and, in recent years, recombinant HVT viruses carrying foreign genes from other avian viruses to protect against both Marek's disease and other avian viral diseases. Testing to monitor and confirm successful vaccination is important, but any such test must differentiate HVT from MDV-1 and MDV-2, as vaccination does not prevent infection with these serotypes. End-point and real-time PCR tests are widely used to detect and differentiate HVT, MDV-1 and MDV-2 but require expensive specialist laboratory equipment and trained operators. Here, we developed and validated two tube-based loop-mediated isothermal amplification tests coupled with detection by lateral flow device readout (LAMP-LFD): an HVT-specific test to detect both conventional and recombinant HVT strains, and a second test using novel LAMP primers to specifically detect the Vaxxitek® recombinant HVT. Specificity was confirmed using DNA extracted from virus-infected cultured cells, and limit of detection was determined using plasmid DNA carrying either the HVT or Vaxxitek® genome. The LAMP-LFD tests accurately detected all HVT vaccines, or Vaxxitek® only, in crude DNA as well as purified DNA extracted from field samples of organs, feathers, or poultry house dust that were confirmed positive for HVT by real-time PCR. These LAMP-LFD tests have potential for specific, rapid, simple, and inexpensive detection of HVT vaccines in the field.
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Affiliation(s)
- Giulia Mescolini
- Avian Pathology Service, Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy
| | - Susan J. Baigent
- Viral Oncogenesis Group, The Pirbright Institute, Woking, United Kingdom
- *Correspondence: Susan J. Baigent
| | - Elena Catelli
- Avian Pathology Service, Department of Veterinary Medical Sciences, University of Bologna, Bologna, Italy
| | - Venugopal K. Nair
- Viral Oncogenesis Group, The Pirbright Institute, Woking, United Kingdom
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Yehia N, El-Sayed HS, Omar SE, Erfan A, Amer F. Genetic evolution of Marek's disease virus in vaccinated poultry farms. Vet World 2021; 14:1342-1353. [PMID: 34220140 PMCID: PMC8243665 DOI: 10.14202/vetworld.2021.1342-1353] [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: 12/30/2020] [Accepted: 04/09/2021] [Indexed: 11/24/2022] Open
Abstract
Background and Aim: The Marek’s disease virus (MDV) is a neoplastic disease causing serious economic losses in poultry production. This study aimed to investigate MDV occurrence in poultry flocks in the Lower Egypt during the 2020 breakout and genetically characterized Meq, gL, and ICP4 genes in field strains of MDV. Materials and Methods: Forty samples were collected from different breeds from eight Egyptian governorates in 2020. All flocks had received a bivalent vaccine (herpesvirus of turkey FC-126 + Rispens CVI988). However, weight loss, emaciation, reduced egg production, paralysis, and rough/raised feather follicles occurred. Samples were collected from feather follicles, liver, spleen, and nerve tissue for diagnosis by polymerase chain reaction. MDV genetic characterization was then performed by sequencing the Meq, gL, and ICP4 genes of five positive samples representing different governorates and breeds. Results: A total of 28 samples were positive for MDV field strains, while two were related to MDV vaccinal strains. All samples tested negative for ALV (A, B, C, D, and J) and REV. Phylogenetic analysis of the Meq gene of sequenced samples revealed that all MDVs were related to the highly virulent European viruses (Gallid herpesvirus 2 ATE and PC12/30) with high amino acid (A.A.) identity 99.2-100%. Alternatively, there was low A.A. identity with the vaccine strains CVI988 and 3004 (up to 82.5%). These results indicate that further investigation of the efficacy of current Egyptian vaccines is required. The Egyptian strains also harbor a specific mutation, allowing clustering into two subgroups (A and B). By mutation analysis of the Meq gene, the Egyptian viruses in our study had R101K, P217A, and E263D mutations present in all Egyptian viruses. Furthermore, R176A and T180A mutations specific to our strains contributed to the high virulence of highly virulent strains. There were no mutations of the gL or ICP4 genes. Conclusion: Further studies should evaluate the protection contributed by current vaccines used in Egypt.
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Affiliation(s)
- Nahed Yehia
- Reference Laboratory for Veterinary Quality Control on Poultry Production, Animal Health Research Institute, Agricultural Research Center, Dokki, Giza 12618, Egypt
| | - Hemat S El-Sayed
- Department of Poultry Diseases, Benha Provincial Laboratory, Animal Health Research Institute, Agricultural Research Center, Giza, Egypt
| | - Sabry E Omar
- Department of Poultry Diseases, Benha Provincial Laboratory, Animal Health Research Institute, Agricultural Research Center, Giza, Egypt
| | - Ahmed Erfan
- Reference Laboratory for Veterinary Quality Control on Poultry Production, Animal Health Research Institute, Agricultural Research Center, Dokki, Giza 12618, Egypt
| | - Fatma Amer
- Reference Laboratory for Veterinary Quality Control on Poultry Production, Animal Health Research Institute, Agricultural Research Center, Dokki, Giza 12618, Egypt
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6
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Yehia N, El-Sayed HS, Omar SE, Amer F. Genetic variability of the Avian leukosis virus subgroup J gp85 gene in layer flocks in Lower Egypt. Vet World 2020; 13:1065-1072. [PMID: 32801556 PMCID: PMC7396352 DOI: 10.14202/vetworld.2020.1065-1072] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 04/15/2020] [Indexed: 11/16/2022] Open
Abstract
Aim This study aimed to determine the prevalence of layer flock tumor disease in Lower Egypt during the period of 2018-2019 and to undertake molecular characterization and determine the genetic diversity of all identified viruses. Materials and Methods Forty samples were collected from layer chicken located in six governorates of Lower Egypt during the period of 2018-2019. Samples were taken from tumors in different organs. Tumor tissues were identified by histopathological sectioning and then further confirmed by a reverse-transcription polymerase chain reaction. Finally, genetic evolution of Avian leukosis virus (ALV-J) gp85 gene was studied. Results All the study samples were negative for Marek's disease virus, reticuloendotheliosis virus, ALV (A,B,C and D) and 20 samples were positive for ALV-J in backyard in six governrates. Sequencing of ALV-J gp85 gene was performed for six representative samples (one from each governorate), and they were found to be genetically related to prototype virus HPRS-1003 (identity percentage: 91.2-91.8%), but they were from a different group that was similar to the AF88-USA strain (first detected in 2000) with specific mutations, and they differed from a strain that was previously isolated in Egypt in 2005, forming two different subgroups (I and II) that had mutations in the hr1domain (V128F, R136A) and hr2 domain (S197G, E202K). Conclusion The ALV-J virus was the main cause of neoplastic disease in layer chickens from Lower Egypt in the period of 2018-2019. We found that the genetic evolution of ALV-J gp85 gene was related to prototype virus HPRS-1003 but in a different group with a specific mutation. Further studies are needed to evaluate the antigenicity and pathogenicity of recently detected ALV-J strains.
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Affiliation(s)
- Nahed Yehia
- Reference Laboratory for Veterinary Quality Control on Poultry Production, Animal Health Research Institute, Agriculture Research Center, Giza 12618, Egypt
| | - Hemat S El-Sayed
- Department of Poultry Diseases, Benha Provincial Laboratory, Animal Health Research Institute, Agriculture Research Center, Giza 12618, Egypt
| | - Sabry E Omar
- Department of Poultry Diseases, Benha Provincial Laboratory, Animal Health Research Institute, Agriculture Research Center, Giza 12618, Egypt
| | - Fatma Amer
- Reference Laboratory for Veterinary Quality Control on Poultry Production, Animal Health Research Institute, Agriculture Research Center, Giza 12618, Egypt
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Mescolini G, Lupini C, Davidson I, Massi P, Tosi G, Fiorentini L, Catelli E. Molecular characterization of a Marek's disease virus strain detected in tumour-bearing turkeys. Avian Pathol 2019; 49:202-207. [PMID: 31702386 DOI: 10.1080/03079457.2019.1691715] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Marek's disease (MD) is a lymphoproliferative disease caused by Gallid alphaherpesvirus 2 (GaHV-2), which primarily affects chickens. However, the virus is also able to induce tumours in turkeys, albeit less frequently than in chickens. This study reports the molecular characterization of a GaHV-2 strain detected in a flock of Italian meat-type turkeys exhibiting visceral lymphomas. Sequencing and phylogenetic analysis of the meq gene revealed that the turkey GaHV-2 has molecular features of high virulence and genetic similarity with GaHV-2 strains recently detected in Italian commercial and backyard chickens. GaHV-2 is ubiquitous among chickens despite vaccination, and chicken-to-turkey transmission is hypothesized due to the presence of broilers in neighbouring pens.RESEARCH HIGHLIGHTS A GaHV-2 strain from Italian turkeys was molecularly characterized.The turkey strain presented molecular characteristics of high virulence in its meq gene.The turkey strain was closely related to previously detected chicken strains.
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Affiliation(s)
- Giulia Mescolini
- Department of Veterinary Medical Sciences, University of Bologna, Ozzano dell'Emilia, BO, Italy
| | - Caterina Lupini
- Department of Veterinary Medical Sciences, University of Bologna, Ozzano dell'Emilia, BO, Italy
| | - Irit Davidson
- Division of Avian Diseases, Kimron Veterinary Institute, Bet Dagan, Israel
| | - Paola Massi
- Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Sezione Diagnostica di Forlì, Forlì, FC, Italy
| | - Giovanni Tosi
- Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Sezione Diagnostica di Forlì, Forlì, FC, Italy
| | - Laura Fiorentini
- Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Sezione Diagnostica di Forlì, Forlì, FC, Italy
| | - Elena Catelli
- Department of Veterinary Medical Sciences, University of Bologna, Ozzano dell'Emilia, BO, Italy
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Work TM, Dagenais J, Stacy BA, Ladner JT, Lorch JM, Balazs GH, Barquero-Calvo E, Berlowski-Zier BM, Breeden R, Corrales-Gómez N, Gonzalez-Barrientos R, Harris HS, Hernández-Mora G, Herrera-Ulloa Á, Hesami S, Jones TT, Morales JA, Norton TM, Rameyer RA, Taylor DR, Waltzek TB. A novel host-adapted strain of Salmonella Typhimurium causes renal disease in olive ridley turtles (Lepidochelys olivacea) in the Pacific. Sci Rep 2019; 9:9313. [PMID: 31249336 PMCID: PMC6597722 DOI: 10.1038/s41598-019-45752-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 06/14/2019] [Indexed: 01/01/2023] Open
Abstract
Salmonella spp. are frequently shed by wildlife including turtles, but S. enterica subsp. enterica serovar Typhimurium or lesions associated with Salmonella are rare in turtles. Between 1996 and 2016, we necropsied 127 apparently healthy pelagic olive ridley turtles (Lepidochelys olivacea) that died from drowning bycatch in fisheries and 44 live or freshly dead stranded turtles from the west coast of North and Central America and Hawaii. Seven percent (9/127) of pelagic and 47% (21/44) of stranded turtles had renal granulomas associated with S. Typhimurium. Stranded animals were 12 times more likely than pelagic animals to have Salmonella-induced nephritis suggesting that Salmonella may have been a contributing cause of stranding. S. Typhimurium was the only Salmonella serovar detected in L. olivacea, and phylogenetic analysis from whole genome sequencing showed that the isolates from L. olivacea formed a single clade distinct from other S. Typhimurium. Molecular clock analysis revealed that this novel clade may have originated as recently as a few decades ago. The phylogenetic lineage leading to this group is enriched for non-synonymous changes within the genomic area of Salmonella pathogenicity island 1 suggesting that these genes are important for host adaptation.
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Affiliation(s)
- Thierry M Work
- US Geological Survey, National Wildlife Health Center, Honolulu Field Station, Honolulu, Hawaii, 96850, United States of America.
| | - Julie Dagenais
- US Geological Survey, National Wildlife Health Center, Honolulu Field Station, Honolulu, Hawaii, 96850, United States of America
| | - Brian A Stacy
- NOAA Fisheries, Office of Protected Resources, University of Florida, Gainesville, Florida, 32603, United States of America
| | - Jason T Ladner
- The Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, 86011, United States of America
| | - Jeffrey M Lorch
- US Geological Survey, National Wildlife Health Center, Madison, Wisconsin, 53711, United States of America
| | - George H Balazs
- Golden Honu Services of Oceania, Honolulu, Hawaii, 96825, United States of America
| | - Elías Barquero-Calvo
- Escuela de Medicina Veterinaria (EMV), Universidad Nacional Costa Rica, Heredia, 3000, Costa Rica
| | - Brenda M Berlowski-Zier
- US Geological Survey, National Wildlife Health Center, Madison, Wisconsin, 53711, United States of America
| | - Renee Breeden
- US Geological Survey, National Wildlife Health Center, Honolulu Field Station, Honolulu, Hawaii, 96850, United States of America
| | | | - Rocio Gonzalez-Barrientos
- Pathology Area National Service of Animal Health (SENASA), Ministry of Agriculture and Livestock, Heredia, 3000, Costa Rica
| | - Heather S Harris
- NOAA Fisheries West Coast Region, Morro Bay, California, United States of America
| | - Gabriela Hernández-Mora
- Pathology Area National Service of Animal Health (SENASA), Ministry of Agriculture and Livestock, Heredia, 3000, Costa Rica
| | - Ángel Herrera-Ulloa
- Bacteriology Area, National Service of Animal Health (SENASA), Ministry of Agriculture and Livestock, Heredia, 3000, Costa Rica
| | - Shoreh Hesami
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida, 32603, United States of America
| | - T Todd Jones
- NOAA Fisheries, Pacific Islands Fisheries Science Center, Honolulu, Hawaii, 96818, United States of America
| | - Juan Alberto Morales
- Escuela de Medicina Veterinaria (EMV), Universidad Nacional Costa Rica, Heredia, 3000, Costa Rica
| | - Terry M Norton
- Georgia Sea Turtle Center/Jekyll Island Authority, Jekyll Island, Georgia, 31527, United States of America
| | - Robert A Rameyer
- US Geological Survey, National Wildlife Health Center, Honolulu Field Station, Honolulu, Hawaii, 96850, United States of America
| | - Daniel R Taylor
- US Geological Survey, National Wildlife Health Center, Madison, Wisconsin, 53711, United States of America
| | - Thomas B Waltzek
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida, 32603, United States of America
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Othman I, Aklilu E. Marek's disease herpesvirus serotype 1 in broiler breeder and layer chickens in Malaysia. Vet World 2019; 12:472-476. [PMID: 31089320 PMCID: PMC6487246 DOI: 10.14202/vetworld.2019.472-476] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 02/20/2019] [Indexed: 11/16/2022] Open
Abstract
Aim: This study aimed to investigate the occurrence of Marek’s disease (MD) in five poultry farms in Malaysia using postmortem examination, histopathology, and polymerase chain reaction (PCR). Materials and Methods: Tissue samples were collected from 24 broiler breeder chickens from four commercial broiler breeder farms and six layer chickens from one layer farm. Gross and histopathological examinations and PCR amplification of the gene encoding for avian MD herpesvirus (MDV-1) were conducted. Results: Gross pathological changes including hepatomegaly, splenomegaly, lymphomatous lesion at the mesentery, oviduct atrophy, and follicular atresia with lymphomatous were observed, whereas diffuse multifocal whitish infiltration of the spleen, neoplastic infiltration in the liver, intrafollicular lymphoid infiltration of the bursa of Fabricius, and lymphomatous tumor at the mesentery were seen on histopathological examinations. Confirmation by PCR showed that a total of 16 (53.33%) samples were positive for avian MDV-1. Although the outbreak involved a much larger number of birds in the respective farms, our investigation was limited based on resource and time frame allocated for the study. Conclusion: The findings from this study help in emphasizing the potential threats of MDV to the poultry industry globally, in general, and in Malaysia, in particular. As the scope of the current study is limited, future studies focusing on MDV pathogenesis, typing, and causes of vaccine failures are recommended.
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Affiliation(s)
- Iryanti Othman
- Department of Paraclinical Studies, Faculty of Veterinary Medicine, Universiti Malaysia Kelantan, 16100 Pengkalan Chepa, Kota Bharu Kelantan
| | - Erkihun Aklilu
- Department of Paraclinical Studies, Faculty of Veterinary Medicine, Universiti Malaysia Kelantan, 16100 Pengkalan Chepa, Kota Bharu Kelantan
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Shaheen HA, Hussein HA, Elsafty MM, Shalaby MA. Genetic resistance of eight native Egyptian chicken breeds having chicken B-cell marker 6 gene post-challenge with field strain of Marek's disease-induced tumor virus. Vet World 2018; 11:1510-1515. [PMID: 30532510 PMCID: PMC6247869 DOI: 10.14202/vetworld.2018.1510-1515] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Accepted: 09/24/2018] [Indexed: 11/16/2022] Open
Abstract
Aim: The aim of this work was to detect chicken B-cell marker 6 (ChB6) gene in some native breeds in Egypt and find the relationship between founded genes in these different breeds to determine the resistance of native Egyptian breeds of chicken to Marek’s disease (MD). Materials and Methods: A total of 14 different chicken breeds (30 each) including ten native breeds in addition to SPF Lohmann, High Line, Bovans, and Roodiland were used. Blood samples were collected for the detection of (ChB6) by polymerase chain reaction (PCR) assay and sequenced to determine the presence or absence of ChB6 gene. Experimental infection was done using local field isolated MD virus (MDV) of 11 (1 day old) unvaccinated chick breeds having no maternal antibodies against MDV. Ten breeds of them carry ChB6 gene, eight breeds were native, and the rest two breeds were SPF Lohmann and High Line in addition to a group of ChB6 gene-lacking breed (Bovans) were infected. Spleen samples were collected from all infected breeds at 20th, 25th, 30th, 35th, and 40th weeks post-infection and tested by PCR assay for the detection of MDV. Furthermore, at 40th week post-infection, tumorized spleen sample of Bovans breed was collected and prepared for examination by transmission electron microscope (TEM) to confirm the presence of MDV. Results: Our results revealed the positivity of 10 out of 14 breeds (Gimmizah, Sinai, Dandarawi, Fayoumi, Golden Montazah, Matrouh, Beheri, Dokki, SPF Lohmann, and High Line) to the presence of ChB6 gene and resistance to MDV infection, while the Bovans, Mandarah, Inshas and Roodiland breeds lack the ChB6 gene and are susceptible to MDV infection. The collected spleen samples revealed negative for the presence of challenged MDV by PCR in 10 breeds (Gimmizah, Sinai, Dandarawi, Fayoumi, Golden Montazah, Matrouh, Beheri, Dokki, SPF Lohmann, and High Line) and positive for Bovans breed. TEM is used to confirm MDV infection in Bovans group which demonstrated tumors. Conclusion: The study confirms the relationship between the presence of ChB6 gene in our native breeds and the absence of tumors.
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Affiliation(s)
- Hala A Shaheen
- Central Laboratory for Evaluation of Veterinary Biologics, Cairo, Egypt
| | - H A Hussein
- Department of Virology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - M M Elsafty
- Central Laboratory for Evaluation of Veterinary Biologics, Cairo, Egypt
| | - M A Shalaby
- Department of Virology, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
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11
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Song H, Bae Y, Park S, Kwon H, Lee H, Joh S. Loop-mediated isothermal amplification assay for detection of four immunosuppressive viruses in chicken. J Virol Methods 2018; 256:6-11. [PMID: 29476761 DOI: 10.1016/j.jviromet.2018.02.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Revised: 01/31/2018] [Accepted: 02/19/2018] [Indexed: 11/28/2022]
Abstract
Loop-mediated isothermal amplification (LAMP) methods to detect chicken infectious anemia virus (CIAV), reticuloendotheliosis virus (REV), and Marek's disease virus (MDV), and a reverse transcription (RT)-LAMP assay to detect infectious bursal disease virus (IBDV), were developed. The CIAV-LAMP, REV-LAMP, MDV-LAMP, and IBDV-RT-LAMP methods were performed using four sets of six primers targeting the VP1 gene of CIAV, the gp90 gene of REV, the Meq gene of MDV, and the VP2 gene of IBDV. The results (a change in color) were observed visually. The methods showed high specificity and sensitivity. The detection limits were 50 genomic copies of CIAV, 16 genomic copies of REV, 20 genomic copies of MDV, and 250 genomic copies of IBDV. When used to test clinical samples, the results of the LAMP assays were in 100% agreement with a previously described PCR. Therefore, the LAMP assays are simple, rapid, highly sensitive, and specific methods for detecting four immune-suppressive viruses.
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Affiliation(s)
- HyeSoon Song
- Avian Disease Division, Animal and Plant Quarantine Agency, HyukSin 8-ro, GimCheon, Republic of Korea
| | - YouChan Bae
- Avian Disease Division, Animal and Plant Quarantine Agency, HyukSin 8-ro, GimCheon, Republic of Korea
| | - SeokChan Park
- Avian Disease Division, Animal and Plant Quarantine Agency, HyukSin 8-ro, GimCheon, Republic of Korea
| | - HyukMan Kwon
- Avian Disease Division, Animal and Plant Quarantine Agency, HyukSin 8-ro, GimCheon, Republic of Korea
| | - HeeSoo Lee
- Avian Disease Division, Animal and Plant Quarantine Agency, HyukSin 8-ro, GimCheon, Republic of Korea
| | - SeongJoon Joh
- Avian Disease Division, Animal and Plant Quarantine Agency, HyukSin 8-ro, GimCheon, Republic of Korea.
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12
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Ishihara Y, Esaki M, Saitoh S, Yasuda A. Combination of Two Marek's Disease Virus Vectors Shows Effective Vaccination Against Marek's Disease, Infectious Bursal Disease, and Newcastle Disease. Avian Dis 2017; 60:473-9. [PMID: 27309290 DOI: 10.1637/11359-122615-regr] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Herpesvirus of turkeys (HVT) is a widely used vector for poultry vaccines. However, different HVTs expressing different foreign antigens cannot always be used simultaneously because of the risk of recombination and interference. In this study, we inoculated a mixture of an HVT-expressing the antigen of Newcastle disease virus (NDV; HVT/ND) and Marek's disease virus (MDV) serotype 1 Rispens virus expressing the antigen of infectious bursal disease virus (IBD; Ripens/IBD) into chickens. This mixture showed 94%, 100%, or 94% protection against MDV, IBDV, or NDV challenge, respectively. In conclusion, the combination of Rispens/IBD and HVT/ND is effective for vaccination against MDV, IBDV, and NDV without significant interference.
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Affiliation(s)
- Yukari Ishihara
- Ceva Animal Health (Japan Campus), 1-6 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045 Japan
| | - Motoyuki Esaki
- Ceva Animal Health (Japan Campus), 1-6 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045 Japan
| | - Shuji Saitoh
- Ceva Animal Health (Japan Campus), 1-6 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045 Japan
| | - Atsushi Yasuda
- Ceva Animal Health (Japan Campus), 1-6 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045 Japan
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Murata S, Chang KS, Lee SI, Konnai S, Onuma M, Ohashi K. Development of a Nested Polymerase Chain Reaction Method to Detect Oncogenic Marek's Disease Virus from Feather Tips. J Vet Diagn Invest 2016; 19:471-8. [PMID: 17823389 DOI: 10.1177/104063870701900503] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
For the easy survey of Marek's disease virus (MDV), feather tip–derived DNA from MDV-infected chickens can be used because feather tips are easy to collect and feather follicle epithelium is known to be the only site of productive replication of cell-free MDV. To develop a diagnostic method to differentiate highly virulent strains of MDV from the attenuated MDV vaccine strain, CVI988, which is widely used, nested polymerase chain reaction (PCR) was performed to detect a segment of the meq gene in feather tip samples of chickens experimentally infected with MDV. In chickens infected with Md5, a strain of oncogenic MDV, the meq gene was consistently detected, whereas the L- meq gene, in which a 180–base pair (180-bp) sequence is inserted into the meq gene, was detected in CVI988-infected chickens. Moreover, the meq gene was mainly detected even in chickens co-infected with both Md5 and CVI988. These results suggest that this method is appropriate for the surveillance of the highly virulent MDV infection in the field.
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Affiliation(s)
- Shiro Murata
- Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
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14
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Kilany WH, Safwat M, Mohammed SM, Salim A, Fasina FO, Fasanmi OG, Shalaby AG, Dauphin G, Hassan MK, Lubroth J, Jobre YM. Protective Efficacy of Recombinant Turkey Herpes Virus (rHVT-H5) and Inactivated H5N1 Vaccines in Commercial Mulard Ducks against the Highly Pathogenic Avian Influenza (HPAI) H5N1 Clade 2.2.1 Virus. PLoS One 2016; 11:e0156747. [PMID: 27304069 PMCID: PMC4909235 DOI: 10.1371/journal.pone.0156747] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 05/18/2016] [Indexed: 02/05/2023] Open
Abstract
In Egypt, ducks kept for commercial purposes constitute the second highest poultry population, at 150 million ducks/year. Hence, ducks play an important role in the introduction and transmission of avian influenza (AI) in the Egyptian poultry population. Attempts to control outbreaks include the use of vaccines, which have varying levels of efficacy and failure. To date, the effects of vaccine efficacy has rarely been determined in ducks. In this study, we evaluated the protective efficacy of a live recombinant vector vaccine based on a turkey Herpes Virus (HVT) expressing the H5 gene from a clade 2.2 H5N1 HPAIV strain (A/Swan/Hungary/499/2006) (rHVT-H5) and a bivalent inactivated H5N1 vaccine prepared from clade 2.2.1 and 2.2.1.1 H5N1 seeds in Mulard ducks. A 0.3ml/dose subcutaneous injection of rHVT-H5 vaccine was administered to one-day-old ducklings (D1) and another 0.5ml/dose subcutaneous injection of the inactivated MEFLUVAC was administered at 7 days (D7). Four separate challenge experiments were conducted at Days 21, 28, 35 and 42, in which all the vaccinated ducks were challenged with 106EID50/duck of H5N1 HPAI virus (A/chicken/Egypt/128s/2012(H5N1) (clade 2.2.1) via intranasal inoculation. Maternal-derived antibody regression and post-vaccination antibody immune responses were monitored weekly. Ducks vaccinated at 21, 28, 35 and 42 days with the rHVT-H5 and MEFLUVAC vaccines were protected against mortality (80%, 80%, 90% and 90%) and (50%, 70%, 80% and 90%) respectively, against challenges with the H5N1 HPAI virus. The amount of viral shedding and shedding rates were lower in the rHVT-H5 vaccine groups than in the MEFLUVAC groups only in the first two challenge experiments. However, the non-vaccinated groups shed significantly more of the virus than the vaccinated groups. Both rHVT-H5 and MEFLUVAC provide early protection, and rHVT-H5 vaccine in particular provides protection against HPAI challenge.
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Affiliation(s)
- Walid H. Kilany
- Reference Laboratory for Veterinary Quality Control on Poultry Production (NLQP), Animal Health Research Institute, P.O. Box, 264, Giza, Egypt
- * E-mail: (WHK); (FOF)
| | - Marwa Safwat
- Reference Laboratory for Veterinary Quality Control on Poultry Production (NLQP), Animal Health Research Institute, P.O. Box, 264, Giza, Egypt
| | - Samy M. Mohammed
- Reference Laboratory for Veterinary Quality Control on Poultry Production (NLQP), Animal Health Research Institute, P.O. Box, 264, Giza, Egypt
- Food and Agriculture Organization of the United Nations (FAO)–Emergency Center of Transboundary Animal Diseases (ECTAD), P.O. Box, 2223, Giza, Egypt
| | - Abdullah Salim
- Reference Laboratory for Veterinary Quality Control on Poultry Production (NLQP), Animal Health Research Institute, P.O. Box, 264, Giza, Egypt
| | - Folorunso Oludayo Fasina
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, South Africa
- * E-mail: (WHK); (FOF)
| | - Olubunmi G. Fasanmi
- Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, & Department of Animal Health, Federal College of Animal Health and Production Technology, Ibadan, Nigeria
| | - Azhar G. Shalaby
- Reference Laboratory for Veterinary Quality Control on Poultry Production (NLQP), Animal Health Research Institute, P.O. Box, 264, Giza, Egypt
| | - Gwenaelle Dauphin
- Food and Agriculture Organization (FAO) Viale delle Terme di Caracalla, 00153 Rome, Italy
| | - Mohammed K. Hassan
- Reference Laboratory for Veterinary Quality Control on Poultry Production (NLQP), Animal Health Research Institute, P.O. Box, 264, Giza, Egypt
| | - Juan Lubroth
- Food and Agriculture Organization (FAO) Viale delle Terme di Caracalla, 00153 Rome, Italy
| | - Yilma M. Jobre
- Food and Agriculture Organization of the United Nations (FAO)–Emergency Center of Transboundary Animal Diseases (ECTAD), P.O. Box, 2223, Giza, Egypt
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Direct detection of Marek's disease virus in poultry dust by loop-mediated isothermal amplification. Arch Virol 2014; 159:3083-7. [PMID: 24986718 PMCID: PMC4200374 DOI: 10.1007/s00705-014-2157-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Accepted: 06/19/2014] [Indexed: 12/03/2022]
Abstract
Marek’s disease virus (MDV) is a serious concern for poultry production and represents a unique herpesvirus model. MDV can be shed by doubly infected chickens despite vaccination. The fully infectious MDV particles are produced in the feather follicle epithelium (FFE), and MDV remains infectious for many months in fine skin particles and feather debris. Molecular biology methods including PCR and real-time PCR have been shown to be valuable for the detection of MDV DNA in farm dust. Recently, loop-mediated isothermal amplification (LAMP) was found to be useful in the detection of MDV in feathers and internal organs of infected chickens. LAMP is also less affected by the inhibitors present in DNA samples. Taking into account the advantages of LAMP, direct detection of MDV DNA in poultry dust has been conducted in this research. The detection of MDV DNA was possible in 11 out of the 12 examined dust samples without DNA extraction. The DNA was retrieved from dust samples by dilution and incubation at 95 °C for 5 min. The direct detection of MDV DNA in the dust was possible within 30 min using a water bath and UV light. The results were confirmed by electrophoresis and melting curve analysis of the LAMP products. Our results show that LAMP may be used to test for the presence of virulent MDV in poultry farm dust without DNA extraction.
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16
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Esaki M, Noland L, Eddins T, Godoy A, Saeki S, Saitoh S, Yasuda A, Dorsey KM. Safety and efficacy of a turkey herpesvirus vector laryngotracheitis vaccine for chickens. Avian Dis 2014; 57:192-8. [PMID: 24689173 DOI: 10.1637/10383-092412-reg.1] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Turkey herpesvirus vector laryngotracheitis vaccine (HVT/LT) expressing the glycoprotein B gene of laryngotracheitis virus (LTV) has been developed. In vitro growth kinetics of HVT/LT were similar to those of parental turkey herpesvirus (HVT), FC-126 strain. Genetic and phenotypic stabilities of HVT/LT after in vitro (in cell culture) or in vivo (in chickens) passage were confirmed by various assays, including Southern blot analysis, western blot analysis, and an indirect immunofluorescence assay. Safety of HVT/LT was assessed by an overdose study as well as by a backpassage study in specific-pathogen-free (SPF) chickens. The overdose study indicated that HVT/LT did not cause any adverse effects in chickens. The backpassage study confirmed that HVT/LT does not revert to virulence after five passages in chickens. The vaccine did not transmit laterally from vaccinated chickens to commingled nonvaccinated chickens. Efficacy of HVT/LT was evaluated in SPF layer chickens after vaccination by the subcutaneous route at 1 day of age. The majority of the vaccinated chickens (92%-100%) were protected against challenge with virulent LTV at 7 wk of age. Efficacy of HVT/LT was further evaluated in broiler chickens from a commercial source after in ovo vaccination to embryos at 18 days of incubation. After challenge with virulent LTV at 21 and 35 days of age, 67% and 87% of HVT/LT-vaccinated chickens did not develop LT clinical signs, respectively, while 100% (21 days of age) and 73% (35 days of age) of the challenge control chickens showed clinical signs of LT. These results suggest that HVT/LT is a safe and efficacious vaccine for control of laryngotracheitis (LT).
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17
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Walkden-Brown SW, Islam AFA, Groves PJ, Rubite A, Sharpe SM, Burgess SK. Development, application, and results of routine monitoring of Marek's disease virus in broiler house dust using real-time quantitative PCR. Avian Dis 2013; 57:544-54. [PMID: 23901774 DOI: 10.1637/10380-92112-reg.1] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Results are presented from four studies between 2002 and 2011 into the feasibility of routinely monitoring Marek's disease virus serotype 1 (MDV-1) in broiler house dust using real-time quantitative PCR (qPCR) measurement. Study 1 on two farms showed that detection of MDV-1 occurred earlier on average in dust samples tested using qPCR than standard PCR and in spleen samples from five birds per shed assayed for MDV-1 by qPCR or standard PCR. DNA quality following extraction from dust had no effect on detection of MDV-1. Study 2 demonstrated that herpesvirus of turkeys (HVT) and MDV serotype 2 (MDV-2) in addition to MDV-1 could be readily amplified from commercial farm dust samples, often in mixtures. MDV-2 was detected in 11 of 20 samples despite the absence of vaccination with this serotype. Study 3 investigated the reproducibility and sensitivity of the qPCR test and the presence of inhibitors in the samples. Samples extracted and amplified in triplicate showed a high level of reproducibility except at very low levels of virus near the limit of detection. Mixing of samples prior to extraction provided results consistent with the proportions in the mixture. Tests for inhibition showed that if the template contained DNA in the range 0.5-20 ng/microl no inhibition of the reaction was detectable. The sensitivity of the tests in terms of viral copy number (VCN) per milligram of dust was calculated to be in the range 24-600 VCN/mg for MDV-1, 48-1200 VCN/mg for MDV-2, and 182-4560 VCN/mg for HVT. In study 4 the results of 1976 commercial tests carried out for one company were analyzed. Overall 23.1% of samples were positive for MDV-1, 26.1% in unvaccinated and 16.4% in vaccinated chickens. There was marked regional and temporal variation in the proportion of positive samples and the MDV-1 load. The tests were useful in formulating Marek's disease vaccination strategies. The number of samples submitted has increased recently, as has the incidence of positive samples. These studies provide strong evidence that detection and quantitation of MDV-1, HVT, and MDV-2 in poultry house dust using qPCR is robust, sensitive, reproducible, and meaningful, both biologically and commercially. Tactical vaccination based on monitoring of MDV-1 rather than routine vaccination may reduce selection pressure for increased virulence in MDV-1.
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Affiliation(s)
- Stephen W Walkden-Brown
- Animal Science, School of Environmental and Rural Science, University of New England, Armidale, NSW Australia.
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Singh SD, Barathidasan R, Kumar A, Deb R, Verma AK, Dhama K. Recent trends in diagnosis and control of Marek's disease (MD) in poultry. Pak J Biol Sci 2012; 15:964-970. [PMID: 24199474 DOI: 10.3923/pjbs.2012.964.970] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Marek's Disease (MD), caused by Marek's Disease Virus (MDV) is a highly contagious oncogenic and neuropathic disease of chickens responsible for great economic losses to the poultry industry all around the world and characterized by development of CD4+T cell lymphomas as well as infiltration of nerves and visceral organs by lymphocytes. MD is one of the most common lymphoproliferative diseases of chickens which cause mononuclear cell infiltration in one or more of the following tissues: peripheral nerves, gonads, lymphoid organs, iris, muscle, skin and other visceral organs resulting into development of tumours in visceral organs, paralysis of legs, wings and neck, grey eye (iris) or irregular pupil, vision impairment, blindness, skin lesions and immunosuppression, all of which can be accompanied by non-specific signs such as anorexia, weight loss and poor performance. Today there are evolving highly pathogenic isolates of MDV around the world capable of overwhelming the protection from currently employed vaccines. Thus MD poses a big challenge to the welfare and wellbeing of the poultry with increased condemnation of carcass, loss of productivity and quality products, leading to huge economic losses. It is also an immunosuppressive disease and causes increased susceptibility to other infections. The present review discusses in brief about the Marek's disease, its etiology, conventional and advance tools and techniques being used for its diagnosis, prevention and control strategies in poultry.
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Affiliation(s)
- Shambhu Dayal Singh
- Avian Diseases Section, Division of Pathology, Indian Veterinary Research Institute, Izatnagar, Bareilly (U.P.)-243 122
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Cavanagh D. Innovation and discovery: the application of nucleic acid-based technology to avian virus detection and characterization. Avian Pathol 2012; 30:581-98. [PMID: 19184952 DOI: 10.1080/03079450120092071] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Polymerase chain reaction (PCR)-based approaches to the detection, differentiation and characterization of avian pathogens continue to be developed and refined. The PCRs, or reverse transcriptase-PCRs, may be general, designed to detect all or most variants of a pathogen, or to be serotype, genotype or pathotype specific. Progress is being made with respect to making nucleic acid approaches more suitable for use in diagnostic laboratories. Robotic workstations are now available for extraction of nucleic acid from many samples in a short time, for routine diagnosis. Following general PCR, the DNA products are commonly analyzed by restriction endonuclease mapping (restriction fragment length polymorphism), using a small number of restriction endonucleases, based on a large body of sequence data. Increasingly, however, nucleotide sequencing is being used to analyze the DNA product, in part due to the expanding use of non-radioactive sequencing methods that are safe and enable high throughout. In this review, I highlight some recent developments with many avian viruses: Newcastle disease virus; circoviruses in canary and pigeon; infectious bursal disease virus (Gumboro disease virus); avian adenoviruses, including Angara disease/infectious hydropericardium virus, haemorrhagic enteritis virus of turkeys, and egg drop syndrome virus; avian herpesviruses, including infectious laryngotracheitis virus, duck plague virus, psittacine herpesvirus (Pacheco's parrot disease virus), Marek's disease virus and herpesvirus of turkeys; avian leukosis virus (associated with lymphoid leukosis or myeloid leukosis, and egg transmission); avian pneumoviruses (turkey rhinotracheitis virus); avian coronaviruses, including infectious bronchitis virus, turkey coronavirus and pheasant coronavirus; astrovirus, in the context of poult enteritis and mortality syndrome, and avian nephritis virus; and avian encephalomyelitis virus, a picornavirus related to hepatitis A virus.
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Lemiere S, Perozo F, Saint-Vis BD, Diasparra J, Carlotti A, Morillon P, Dancer A, le-Gros FX. Hatchery Vaccination Quality Control of Herpesvirus of Turkey-Infectious Bursal
Disease HVT-IBD Viral Vector Vaccine Application by Specific qPCR. ACTA ACUST UNITED AC 2012. [DOI: 10.3923/ijps.2012.570.576] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Differential detection of avian oncogenic viruses in poultry layer farms and Turkeys by use of multiplex PCR. J Clin Microbiol 2012; 50:2668-73. [PMID: 22675132 DOI: 10.1128/jcm.00457-12] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Avian oncogenic viruses include Marek's disease virus (MDV), a highly contagious herpesvirus, as well as retroviruses such as avian leukosis virus (ALV) subgroups A to J and reticuloendotheliosis virus (REV). In this study, we examined the incidence of these viruses in suspected samples collected from poultry layer farms of South India, mainly in the Namakkal district of Tamil Nadu, a highly dense poultry-growing area in India. The histopathology-positive tissue sections were identified and further confirmed by immunohistochemistry using virus-specific antibodies. The viruses belonging to all 3 groups (MDV, ALV, and REV) were isolated in a cell culture system and confirmed by immunofluorescence using virus-specific antibodies. PCR appeared to be the method of choice for rapid and accurate diagnosis of these viruses. The multiplex PCR primers specific to MDV, ALV, REV, and chicken DNA were designed for rapid differential diagnosis. The specificity of the primers was checked by amplification of DNA from virus-infected cell culture in comparison with uninfected samples, and sensitivity was evaluated by calculating the minimum copy number at which amplification occurs in the cloned PCR products. The sequences of the amplicons were compared by BLAST analysis. PCR tests demonstrated the presence of single, dual, or triple viruses in some of the samples. Of 169 samples screened by multiplex PCR, 9 samples were positive for MDV, 17 samples were positive for ALV, 12 samples were positive for REV, and 17 samples were positive for both ALV and REV. Three samples were positive for all three viruses. ALV-positive samples were further subjected to subgroup-specific PCR, which gave positive results for subgroups B and D but not for subgroup J. Multiplex PCR appeared to be a useful technique for rapid differential diagnosis of avian oncogenic viruses and detection of multiple infections of avian oncogenic viruses under field conditions.
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Rapid detection of the Marek's disease viral genome in chicken feathers by loop-mediated isothermal amplification. J Clin Microbiol 2011; 50:961-5. [PMID: 22170920 DOI: 10.1128/jcm.05408-11] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A loop-mediated isothermal amplification (LAMP) method for the rapid detection of serotype 1 Marek's disease virus (MDV) was developed. The method used a set of three pairs of primers to amplify the MEQ gene for detecting serotype 1 MDV. The MDV LAMP method did not cross-react with serotype 2 and serotype 3, nor did the LAMP primers have binding sites for the common avian DNA viruses (reticuloendotheliosis virus, chicken anemia virus, subgroup J of the avian leukosis virus). Additionally, the assay could detect up to 10 copies of the MEQ gene in the MD viral genome, and it had 10 times higher sensitivity than the traditional PCR methods. The LAMP master mix was stable for 90 days at -20°C. Furthermore, the efficiency of LAMP for detection of serotype 1 MDV in clinical samples was comparable to those of PCR and viral isolation. The LAMP procedure is simple and does not rely on any special equipment. The detection of serotype 1 MDV by LAMP will be useful for detecting and controlling oncogenic Marek's disease.
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Characterization of 132 bp Repeats BamH1-H Region in Pathogenic Marek's Disease Virus of Poultry in Gujarat, India, Using PCR and Sequencing. INDIAN JOURNAL OF VIROLOGY : AN OFFICIAL ORGAN OF INDIAN VIROLOGICAL SOCIETY 2011; 22:72-5. [PMID: 23637506 DOI: 10.1007/s13337-011-0031-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Accepted: 04/21/2011] [Indexed: 10/18/2022]
Abstract
A total of 34 clinical samples and four Marek's disease virus (MDV) vaccines were tested using primer BamH1/BamH2 in layer birds of poultry. Out of 34 samples tested for detection of MDV, 32 samples produced approximately 434 bp product. All the three HVT vaccines as well as SB-1 (MDV-2) vaccine failed to produce the expected amplicons, there by proving negative for the targeted 132 bp repeats of MDV genome by the primers BamH1/BamH2. Resultant PCR products of the field samples were purified and sequenced and resulted in 378 bp long sequences. PCR was found very satisfactory in detecting the presence of MDV either in feather follicle or in tissue samples. Sequencing study has proved beyond doubt that the two representative samples contained two 132 bp repeats indicating the virulent nature of the field virus.
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Barfoed AM, Østergaard E, Frandsen PL, Nielsen EB, Sandberg E, Rasmussen TB. Development of a primer-probe energy transfer based real-time PCR for detection of Marek's disease virus. J Virol Methods 2010; 165:21-6. [DOI: 10.1016/j.jviromet.2009.12.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Revised: 12/04/2009] [Accepted: 12/10/2009] [Indexed: 11/26/2022]
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Abstract
West Nile virus (WNV) is a public health threat and has caused the death of thousands of North American birds. As such, surveillance for WNV has been ongoing, utilizing numerous biological specimens and testing methods. Nonvascular (i.e., fully grown) feathers would provide a simple method of collection from either dead or live birds of all ages and molt cycles, with presumably less biosafety risk compared with other specimen types, including feather pulp. The current study evaluates WNV detection in nonvascular feathers removed from naturally infected avian carcasses of several species groups. Feathers of corvid passeriforms had the highest sensitivity of detection (64%), followed by noncorvid passeriforms (43%), columbiforms (33%), and falconiforms (31%). Storing feathers for 1 year at −20°C or at ambient room temperature resulted in detection rates of infectious WNV of 16% and zero, respectively, but had no effect on detection rates of WNV RNA in a subset of matched feather pairs (47% for both storage temperatures). The efficacy of WNV detection in nonvascular feathers is greatly enhanced by testing multiple feathers. The advantages of using nonvascular feathers over other tissues may outweigh the relatively low detectability of WNV RNA in certain situations such as remote areas lacking resources for acquiring other types of samples or maintaining the cold chain.
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Hatai H, Ochiai K, Umemura T. Detection of Avian Leukosis Virus Genome by a Nested Polymerase Chain Reaction using DNA and RNA from Dried Feather Shafts. J Vet Diagn Invest 2009; 21:519-22. [DOI: 10.1177/104063870902100415] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The nested polymerase chain reaction (nPCR) using frozen feather pulp is useful for detecting fowl glioma-inducing virus (FGV), which belongs to the Avian leukosis virus family, and it has recently been suggested that FGV has spread to ornamental chickens kept in Japanese zoological gardens. In the current study, the practicality of using DNA and RNA from dried feather shafts as PCR samples was examined to establish a simple method for tissue preservation. Feather shafts were collected from 7 FGV-positive chickens and stored at room temperature for 30 days. DNA and RNA were extracted from these dried materials. All DNA and complementary DNA (cDNA) prepared from the RNA showed positive results for chicken β-actin and FGV, respectively. Screening for FGV was performed on Japanese fowls kept in zoological garden N. Of the feather shafts collected from 57 birds, 1 sample tested positive for FGV according to PCR of DNA and cDNA samples from the dried feather shafts. This positive bird originated from zoological garden A and had brain lesions suggestive of fowl glioma. The results suggest that DNA and RNA from dried feather shafts can be used in nPCR to detect the FGV genome.
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Affiliation(s)
- Hitoshi Hatai
- Laboratory of Comparative Pathology
- Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan, and the Japan Societry for the Promotion of Science, Japan
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Fakhrul Islam AFM, Walkden-Brown SW, Groves PJ, Underwood GJ. Kinetics of Marek's disease virus (MDV) infection in broiler chickens 1: effect of varying vaccination to challenge interval on vaccinal protection and load of MDV and herpesvirus of turkey in the spleen and feather dander over time. Avian Pathol 2009; 37:225-35. [DOI: 10.1080/03079450701802230] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Vaccination against Marek's disease reduces telomerase activity and viral gene transcription in peripheral blood leukocytes from challenged chickens. Vaccine 2008; 26:4904-12. [PMID: 18680776 DOI: 10.1016/j.vaccine.2008.07.038] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2008] [Revised: 07/02/2008] [Accepted: 07/16/2008] [Indexed: 11/24/2022]
Abstract
We investigated whether telomerase activity and viral gene transcription were associated with protection against the RB-1B strain of Marek's disease virus (MDV) in chickens vaccinated with Rispens CVI988 or the herpes virus of turkey (HVT). Telomerase activity in peripheral blood leukocytes (PBLs) seemed to be an appropriate marker of lymphoma and levels of viral transcription were correlated with the virulence of MDV strains. Vaccinated protected birds had lower levels of telomerase activity and RB-1B viral gene transcription than unvaccinated chickens infected with RB-1B. The decrease in RB-1B viral transcription was more marked in chickens vaccinated with CVI988 than in those vaccinated with HVT. Indeed, RB-1B viral transcription was not detectable after 14 days post-challenge. In conclusion, telomerase activity and gene transcription in challenge MDV strains are potential new reliable criteria of protection in vaccinated chickens.
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Tan J, Cooke J, Clarke N, Tannock GA. Molecular evaluation of responses to vaccination and challenge by Marek's disease viruses. Avian Pathol 2007; 36:351-9. [PMID: 17899458 DOI: 10.1080/03079450701557149] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
A real-time quantitative polymerase chain reaction was utilized to study the in vivo replication of Marek's disease vaccine viruses and of virulent oncogenic strains. In the first of four experiments, the growth of the herpes virus of turkeys (HVT) vaccine was detectable in various organs of infected chicken embryos, with the highest viral loads being present in the spleen. No evidence was obtained for replication of serotype-1 Marek's disease viruses in embryos. In the second experiment, viral loads were measured in several organs of chickens after administration of the Rispens and HVT vaccines immediately after hatching. Lowest levels were noted for the Rispens strain after 1 to 8 weeks. By contrast, HVT vaccine grew well in all tested organs, with the highest loads being present in the spleen. Highest loads were observed in unvaccinated birds after challenge with the highly virulent strain MPF57 at day 8, especially in lymphoid organs. A positive relationship was observed between viral load and clinical signs, including tumour formation. In a third study, viral loads were measured in the organs of chickens administered the Rispens vaccine on the day of hatch and challenged at day 8 with MPF57. High levels of clinical protection were afforded against MPF57 by the Rispens vaccine but, in confirmation of earlier findings, sterilizing immunity was not induced. In a fourth study, two experiments were conducted--in which viral loads were measured after challenge of chickens vaccinated with HVT in ovo or at day 1 after hatching. Similar protection was achieved in birds vaccinated in ovo on embryonic days 11 and 17, although protection was slightly, but not significantly, lower than for birds vaccinated at day 1.
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Affiliation(s)
- Jianming Tan
- Department of Biotechnology and Environmental Biology, School of Applied Sciences, RMIT University, Bundoora Victoria, Australia
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30
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Baigent SJ, Smith LP, Currie RJW, Nair VK. Correlation of Marek's disease herpesvirus vaccine virus genome load in feather tips with protection, using an experimental challenge model. Avian Pathol 2007; 36:467-74. [DOI: 10.1080/03079450701639319] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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31
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Tan J, Cooke J, Clarke N, Tannock GA. Optimization of methods for the isolation of Marek's disease viruses in primary chicken cell cultures. J Virol Methods 2007; 147:312-8. [PMID: 17976832 DOI: 10.1016/j.jviromet.2007.09.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2007] [Revised: 09/19/2007] [Accepted: 09/20/2007] [Indexed: 11/25/2022]
Abstract
A real-time PCR was used to measure increases in viral DNA in Marek's disease virus (MDV)-infected primary chicken cell cultures in order to optimize methods for viral isolation. Serotype-1 and -3 vaccine and serotype-1 challenge strains exhibited similar growth characteristics, with increases in viral DNA being proportional to inoculum size. Studies of viral growth revealed a linear relationship between increase in MDV copy number and infectious titre, although the rate of increase for copy number was greater. Using real-time PCR, viral DNA yields of the virulent Woodlands strain in infected chicken kidney cultures were shown to be slightly, but not significantly, higher than in chicken embryo kidney cultures and significantly higher than in chicken embryo fibroblast cultures. Viral DNA levels in freshly trypsinised cells suspended in growth medium and infected with the Woodlands strain were higher than levels obtained following the inoculation of monolayer cultures. For cells infected in suspension, no significant enhancement of yield was observed following a medium change after 2-3 days. Peak yields were obtained at days 6-8 after inoculation of all cultures. Findings obtained from the optimization of viral DNA levels were applied to a program for the isolation of Australian strains of serotype-1 viruses from problem flocks over 3 years. Significant improvements were obtained in the isolation rate of strains capable of growing to high titre (>10(4) plaque-forming units/mL) for use in challenge studies.
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Affiliation(s)
- Jianming Tan
- Department of Biotechnology and Environmental Biology, School of Applied Sciences, RMIT University, Bundoora, Victoria 3083, Australia
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32
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Islam AFMF, Walkden-Brown SW, Groves PJ, Underwood GJ. Effects of vaccine dose, virus challenge dose and interval from vaccination to challenge on protection of broiler chickens against Marek's disease virus challenge. Aust Vet J 2007; 85:348-55. [PMID: 17760936 DOI: 10.1111/j.1751-0813.2007.00195.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To examine the effects of varying the doses of turkey herpesvirus (HVT) vaccine and Marek's disease virus (MDV) challenge at two intervals after vaccination on the protection of chickens against challenge with MDV. DESIGN AND PROCEDURE Experiment 1, a dose response study, consisted of 11 doses of HVT vaccine administered at hatch followed by challenge with 100 plaque forming units (pfu) of MDV 5 days post vaccination. Experiment 2, a 2 x 6 x 2 factorial design, included two HVT vaccine types, six different doses of HVT vaccine and 50 pfu and 200 pfu of MDV challenge 2 days post vaccination. All chickens were reared up to day 56 post challenge when all survivors were killed humanely. Dead and killed chickens were examined for gross MD tumours. RESULTS Experiment 1 showed a significant positive linear relationship between dose of HVT vaccine and protective index in chickens challenged 5 days post vaccination. However the range of protective index observed was limited. In Experiment 2 neither HVT vaccine provided significant protection at any dose. There was no significant effect of vaccine type or MDV challenge dose on overall protection against challenge. Chickens challenged with 200 pfu of MDV had significantly higher mortality and MD incidence than those with 50 pfu. CONCLUSIONS HVT vaccine dose had a significant impact on protective index, but vaccination to challenge interval appeared to have greater impact on the protective efficacy of vaccination. A fourfold increase in challenge dose increased mortality rate and incidence of MD.
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Affiliation(s)
- A F M F Islam
- Centre for Animal Health and Welfare, School of Rural Science and Agriculture, The University of New England, Armidale NSW 2351, Australia.
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33
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Murata S, Chang KS, Yamamoto Y, Okada T, Lee SI, Konnai S, Onuma M, Osa Y, Asakawa M, Ohashi K. Detection of the virulent Marek's disease virus genome from feather tips of wild geese in Japan and the Far East region of Russia. Arch Virol 2007; 152:1523-6. [PMID: 17497232 DOI: 10.1007/s00705-007-0982-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Accepted: 04/12/2007] [Indexed: 11/24/2022]
Abstract
Marek's disease (MD) virus (MDV) is known to cause malignant lymphomas in chickens. In 2001, we first reported an MD case in a white-fronted goose (Anser albifrons) in Japan. Therefore, the prevalence of MDV in the wild geese was surveyed by nested PCR using feather-tip samples in Japan and the Far East region of Russia, breeding habitats of geese migrating to Japan. MDV was detected in about 30% of analyzed white-fronted geese. Furthermore, by nucleotide sequence analysis, we confirmed that this MDV shows high homology to very virulent MDV, suggesting that highly virulent MDV is widespread in white-fronted geese migrating between Japan and Far East region of Russia.
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Affiliation(s)
- S Murata
- Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
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34
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Islam AFMF, Walkden-Brown SW, Islam A, Underwood GJ, Groves PJ. Relationship between Marek's disease virus load in peripheral blood lymphocytes at various stages of infection and clinical Marek's disease in broiler chickens. Avian Pathol 2007; 35:42-8. [PMID: 16448942 DOI: 10.1080/03079450500465734] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Vaccination with herpesvirus of turkey (HVT) vaccine provides protection against clinical Marek's disease (MD) but does not preclude infection with wild-type MD virus (MDV). The quantity of MDV detected in circulating lymphocytes during the early period after infection may be a useful predictor of subsequent clinical MD later in the life. A study was designed to quantify MDV and HVT copy number in peripheral blood lymphocytes (PBL) using real-time polymerase chain reaction between days 5 and 35 post-challenge and to relate this to subsequent development of gross MD lesions. Female commercial broiler chickens were vaccinated with HVT or were sham-vaccinated at hatch, then challenged with MDV strain MPF-57 at day 2 post-vaccination and reared in positive-pressure isolators up to 56 days post-challenge, when all survivors were euthanized. All dead and euthanized chickens were examined post mortem for gross MD lesions. Birds were scored for MD lesions and mortality. MDV and HVT genome copy numbers were determined for each PBL sample. There was an increase in HVT load in PBL between days 7 and 37 post-vaccination, with marked increases between days 7 and 16 and again between days 30 and 37. There was a steady increase in MDV load to 35 days post-challenge. The mean MDV copy number (log(10)) was greater in chickens subsequently exhibiting gross MD lesions (5.05 +/- 0.21) than in those that did not (2.88 +/- 0.223), with the largest difference at 14 and 21 days post-challenge (P < 0.001). Quantification of MDV during early infection is therefore a potential tool for monitoring MD in broiler flocks.
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Affiliation(s)
- A F M Fakhrul Islam
- Centre for Animal Health and Welfare, School of Rural Science and Agriculture, The University of New England, Armidale, NSW, 2351, Australia.
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35
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Baigent SJ, Smith LP, Nair VK, Currie RJW. Vaccinal control of Marek's disease: Current challenges, and future strategies to maximize protection. Vet Immunol Immunopathol 2006; 112:78-86. [PMID: 16682084 DOI: 10.1016/j.vetimm.2006.03.014] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Marek's disease is an economically important lymphoid neoplasm of chickens, caused by oncogenic strains of Marek's disease herpesvirus. The disease can be successfully controlled by vaccination with attenuated or non-pathogenic MDV strains. However, vaccine failures do occur as field strains continue to evolve towards pathotypes of greater virulence, and this evolution is likely to be driven by the vaccines themselves. Two general strategies can be considered to improve protection by vaccination. Firstly by the development of novel vaccines, and secondly by maximizing the potential of existing vaccines. This second goal requires investigation of optimal timing and vaccine delivery route, and optimal vaccination regimes for different breeds of chick. Accurate quantitation of Marek's disease vaccine virus in vaccinated chicks will contribute significantly to our understanding of vaccinal protection. We recently developed a real-time polymerase chain reaction (PCR) assay for quantitation of CVI988 vaccine virus in the feather tips, a rich source of viral DNA which can easily be sampled in a non-invasive manner. This PCR test is now used commercially to confirm the successful vaccination of chicks. We have also used the PCR to examine various aspects of vaccination in experimental chicks and commercial chicks with a view to determining how vaccine level in feathers correlates with protection against challenge, and for identifying optimal timing and vaccine delivery route, and optimal vaccination regimes for different breeds of chick. In this article we review some aspects of the current vaccinal control of Marek's disease, before highlighting some of the problems associated with current vaccines and vaccination strategies, and the challenges for the future. We go on to discuss the development and use of our real-time PCR feather test, its current applications and potential opportunities in Marek's disease vaccine research.
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Affiliation(s)
- Susan J Baigent
- Viral Oncogenesis Group, Institute for Animal Health, Compton, Berkshire, RG20 7NN, United Kingdom.
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36
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Abdul-Careem MF, Hunter BD, Nagy E, Read LR, Sanei B, Spencer JL, Sharif S. Development of a real-time PCR assay using SYBR Green chemistry for monitoring Marek's disease virus genome load in feather tips. J Virol Methods 2006; 133:34-40. [PMID: 16300836 DOI: 10.1016/j.jviromet.2005.10.018] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2005] [Revised: 10/11/2005] [Accepted: 10/12/2005] [Indexed: 10/25/2022]
Abstract
Feather follicles of birds infected with Marek's disease virus (MDV) serve as the sole source of infectious virus particles. The present study was aimed at developing a SYBR Green real-time PCR assay to detect and quantify MDV loads in feather tips targeting meq gene of the virus. The assay had a dynamic range of 8 logs, mean inter- and intra-assay coefficient variation (CV) of <5% and minimum detection limit of 15 MDV genome copies when plasmid DNA was used as the template. The sensitivity of the assay was compared with that of the conventional PCR technique and found to be 2.5-10 times more sensitive than the conventional PCR technique. The assay was validated using feather tip DNA preparations derived from chickens infected with 250 plaque forming units (PFU) of RB1B strain of MDV and sampled on days 7, 14, 21 and 28 post-infection (p.i.) along with uninfected chickens. MDV genome was quantifiable in feather tips of infected birds by day 7 p.i. and the number of MDV copies peaked by day 14 p.i., but then gradually decreased by day 28. This reliable real-time PCR assay may be used for monitoring MDV genome loads in tissues of experimentally or naturally infected birds.
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37
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Baigent SJ, Smith LP, Currie RJW, Nair VK. Replication kinetics of Marek's disease vaccine virus in feathers and lymphoid tissues using PCR and virus isolation. J Gen Virol 2006; 86:2989-2998. [PMID: 16227220 DOI: 10.1099/vir.0.81299-0] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
CVI988 (Rispens), an avirulent strain of Marek's disease virus, is the most widely used vaccine against Marek's disease. The kinetics of replication of CVI988 was examined in tissues of chickens vaccinated at either 1 day or 14 days of age and sampled regularly up to 28 days post-vaccination. Age at vaccination had no significant effect on the kinetics of CVI988 virus replication. During the cytolytic phase of infection (1-7 days), virus levels peaked in the spleen, bursa and thymus with very close correlation among these organs. Virus load in peripheral blood lagged behind and did not reach high levels. Significant numbers of virus genomes were detected in the feather tips only after 7 days, but subsequently rose to levels almost 10(3)-fold greater than in the other tissues. This is the first accurate quantitative data for kinetics of CVI988 replication in a variety of tissues. There was good correlation between data from virus isolation and PCR, with real-time PCR being the preferred method for rapid, accurate and sensitive quantification of virus. Feathers were ideal for non-invasive sampling to detect and measure CVI988 in live chickens and, from 10 days onwards, virus load in feather tips was predictive of virus load in lymphoid tissues where immune responses will occur. The potential for real-time PCR analysis of feather samples for further investigation of the mechanism of vaccinal protection, and to assist optimization of vaccination regimes, is discussed.
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Affiliation(s)
- Susan J Baigent
- Viral Oncogenesis Group, Institute for Animal Health, Compton, Berkshire RG20 7NN, UK
| | - Lorraine P Smith
- Viral Oncogenesis Group, Institute for Animal Health, Compton, Berkshire RG20 7NN, UK
| | - Richard J W Currie
- Fort Dodge Animal Health, Flanders Road, Hedge End, Southampton SO30 4QH, UK
| | - Venugopal K Nair
- Viral Oncogenesis Group, Institute for Animal Health, Compton, Berkshire RG20 7NN, UK
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38
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Islam A, Cheetham BF, Mahony TJ, Young PL, Walkden-Brown SW. Absolute quantitation of Marek's disease virus and Herpesvirus of turkeys in chicken lymphocyte, feather tip and dust samples using real-time PCR. J Virol Methods 2005; 132:127-34. [PMID: 16290211 DOI: 10.1016/j.jviromet.2005.10.009] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2005] [Revised: 09/11/2005] [Accepted: 10/03/2005] [Indexed: 10/25/2022]
Abstract
The further development of Taqman quantitative real-time PCR (qPCR) assays for the absolute quantitation of Marek's disease virus serotype 1 (MDV1) and Herpesvirus of turkeys (HVT) viruses is described and the sensitivity and reproducibility of each assay reported. Using plasmid DNA copies, the lower limit of detection was determined to be 5 copies for the MDV1 assay and 75 copies for the HVT assay. Both assays were found to be highly reproducible for Ct values and calculated copy numbers with mean intra- and inter-assay coefficients of variation being less than 5% for Ct and 20% for calculated copy number. The genome copy number of MDV1 and HVT viruses was quantified in PBL and feather tips from experimentally infected chickens, and field poultry dust samples. Parallelism was demonstrated between the plasmid-based standard curves, and standard curves derived from infected spleen material containing both viral and host DNA, allowing the latter to be used for absolute quantification. These methods should prove useful for the reliable differentiation and absolute quantitation of MDV1 and HVT viruses in a wide range of samples.
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Affiliation(s)
- Aminul Islam
- Centre for Animal Health and Welfare, School of Rural Science and Agriculture, University of New England, Armidale, NSW 2351, Australia.
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39
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Dalgaard TS, Vitved L, Skjødt K, Thomsen B, Labouriau R, Jensen KH, Juul-Madsen HR. Molecular Characterization of Major Histocompatibility Complex Class I (B-F) mRNA Variants from Chickens Differing in Resistance to Marek's Disease. Scand J Immunol 2005; 62:259-70. [PMID: 16179013 DOI: 10.1111/j.1365-3083.2005.01652.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this study, the relative distributions of two alternatively polyadenylated chicken major histocompatibility complex (MHC) mRNA isoforms of approximately 1.5 and 1.9 kb were analysed in spleen cells from chickens homozygous for the MHC haplotypes B21 and B19v1 as well as in heterozygous B19v1/B21 birds. Both isoforms are likely to encode classical MHC class I (B-F) alpha chains. The B19v1 and B21 MHC haplotypes confer different levels of protection against Marek's disease (MD), which is caused by infection with MD virus (MDV). In spleen cells, MD-resistant B21 birds were shown to have the highest percentage of the 1.5 kb variant relative to the total MHC class I expression, MD-susceptible B19v1 birds the lowest and B19v1/B21 birds an intermediate percentage. Infection of 4-week-old chickens with the GA strain of MDV was shown to cause a significant increase in the relative amount of 1.5 kb transcripts in B21 birds 32 days postinfection (dpi). Alternatively polyadenylated mRNA isoforms may encode identical proteins, but differences in the 3' untranslated region (UTR) can influence polyadenylation, mRNA stability, intracellular localization and translation efficiency. It was shown that the increased 1.5 kb percentage in B21 birds 32 days postinfection may be a result of a change in the choice of poly(A) site rather than a locus-specific upregulated transcription of the BF1 gene that preferentially expresses the 1.5 kb variant. Furthermore, the 3' end of the 1.5 kb mRNA variants deriving from B19v1 and B21 chickens was characterized by Rapid Amplification of cDNA Ends (RACE) and sequencing. No potentially functional elements were identified in the 3' UTR of the RACE products corresponding to this short isoform. However, variation in polyadenylation site was observed between the BF1 and BF2 mRNA transcripts and alternative splicing-out of the sequence (exon 7) encoding the second segment of the cytoplasmic part of the mature BF2*19 molecules. This alternative exon 7 splice variant was also detected in other MD-susceptible haplotypes, but not in the MD-resistant B21 and B21-like haplotypes, suggesting a potential role of exon 7 in MHC-related MD resistance.
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Affiliation(s)
- T S Dalgaard
- Department of Animal Health, Welfare and Nutrition, Danish Institute of Agricultural Sciences, Research Centre Foulum, Tjele, Denmark.
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40
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Baigent SJ, Petherbridge LJ, Howes K, Smith LP, Currie RJW, Nair VK. Absolute quantitation of Marek's disease virus genome copy number in chicken feather and lymphocyte samples using real-time PCR. J Virol Methods 2005; 123:53-64. [PMID: 15582699 DOI: 10.1016/j.jviromet.2004.08.019] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2004] [Revised: 08/19/2004] [Accepted: 08/23/2004] [Indexed: 10/26/2022]
Abstract
A real-time PCR method was developed, optimised and validated, to enable quantitation of Marek's disease virus genomes as copy number per million host cells. The duplex PCR measured the virus meq gene and host ovotransferrin gene in a single reaction enabling correction for differences in amount of sample DNA added. A bacterial artificial chromosome (BAC) clone of the virus genome, and a plasmid (pGEM-T-ovo) bearing a fragment of the chicken ovotransferrin gene, were used to quantify virus and host genomes respectively. This sensitive and reproducible assay was established initially using chicken lymphocyte DNA, then adapted for feather tip DNA by inclusion of bovine serum albumin in the reaction to overcome inhibition by melanin. The principal advantages are: (1) determination of absolute virus genome copy number enabling meaningful comparison between samples; (2) expression of copy number per million cells, allowing direct correlation with plaque assays; (3) using BAC-cloned whole virus genome as a standard potentially enables any virus gene to be used as the PCR target. This is the first report of quantitation of MDV genomes in feather tips, and application of this assay could significantly further our understanding of pathogenesis, spread, diagnosis, genetic resistance and vaccinal control of Marek's disease.
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Affiliation(s)
- Susan J Baigent
- Viral Oncogenesis Group, Institute for Animal Health, Compton, Berkshire RG20 7NN, UK.
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41
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Islam A, Harrison B, Cheetham BF, Mahony TJ, Young PL, Walkden-Brown SW. Differential amplification and quantitation of Marek's disease viruses using real-time polymerase chain reaction. J Virol Methods 2004; 119:103-13. [PMID: 15158591 DOI: 10.1016/j.jviromet.2004.03.006] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2003] [Revised: 03/09/2004] [Accepted: 03/15/2004] [Indexed: 11/18/2022]
Abstract
Quantitative real-time PCR (qPCR) assays for the three serotypes of Marek's disease virus (MDV) have been developed. An internal control qPCR assay that detects chicken alpha2 (VI) collagen gene was also developed to allow quantitation of MDV. To reduce costs and time, the assays for MDV1 and the internal control were combined into a duplex assay. The sensitivity, specificity, precision, and reproducibility of each assay are reported. The MDV qPCR assays were specific to their target gene when compared using Australian field and vaccine strains of MDV and 10-100-fold more sensitive than standard PCR. Using DNA from infected spleen tissue, the lower limit of detection of total DNA (viral and host combined) was 0.025 ng for the MDV1 and collagen assays, and 0.25 ng for the HVT and MDV2 assays. All assays were found to be highly reproducible for Ct values, but less so for calculated concentrations. MDV1 and HVT were quantitated in spleen tissue of twenty experimentally infected chickens 7-35 days after infection. The relative abundance of MDV1 exhibited a clear peak at day 14 post-infection, whereas HVT displayed an increasing trend over the 35 days post-infection. The duplex assay was optimized such that it was able to accurately quantitate MDV1 in samples of very high, medium, and very low relative abundance of MDV1. These qPCR assays will be useful for reliable differentiation and quantitation of MDV for a range of research and industry applications.
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Affiliation(s)
- Aminul Islam
- Centre for Animal Health and Welfare, School of Rural Science and Agriculture, University of New England, Armidale NSW 2351, Australia.
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42
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Davidson I, Borenshtain R. Novel applications of feather tip extracts from MDV-infected chickens; diagnosis of commercial broilers, whole genome separation by PFGE and synchronic mucosal infection. ACTA ACUST UNITED AC 2003; 38:199-203. [PMID: 14522455 DOI: 10.1016/s0928-8244(03)00177-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Marek's disease virus (MDV) productive replication occurs in the feather follicle epithelium and the feather tips are valuable both for research and disease diagnosis. Three novel applications of feather tip extracts are described now: (A). As a source of DNA for amplifying either MDV and/or ALV-J. In two clinical situations a marked advantage was obtained compared to blood and organs; in broiler breeder flocks with a mixed MDV and ALV-J infection, and in young broilers with neurological Marek's disease (MD). (B). Separation of the large ( approximately 200 kbp) MDV genome directly from the infected chickens. Using pulsed field gel electrophoresis, the DNA extracted from tumors or feather tips was separated and hybridized to a 132 bp tandem repeat MDV probe. Compared to 2/55 polymerase chain reaction (PCR) positive tumor samples, 15/61 feather tip extracts contained whole MDV genomes. (C). Experimental MDV infection was induced by the mucosal route by dripping feather tip extract to the eye and mouth of the bird. That attempted to reproduce the native infection process, however the use of extracts, instead of dry feather dust was a compromise, aimed to synchronize the infection. In one trial, tumors were induced 6 weeks after dripping day-old broilers, while in another, feather tips were PCR positive 16 days after dripping of 2-month-old layers.
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Affiliation(s)
- Irit Davidson
- Division of Avian Diseases, Kimron Veterinary Institute, Bet Dagan 50250, Israel.
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43
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Davidson I, Borenshtain R. The feather tips of commercial chickens are a favorable source of DNA for the amplification of Marek's disease virus and avian leukosis virus, subgroup J. Avian Pathol 2002; 31:237-40. [PMID: 12396346 DOI: 10.1080/03079450220136549] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Marek's disease virus (MDV), a herpesvirus, and avian leukosis virus, subgroup J (ALV-J), a retrovirus, are oncogenic viruses of poultry. The present report describes a case-report study aimed at examining the efficacy of amplifying MDV and/or ALV-J from feather-tip DNA as compared with DNA purified from liver and spleen. We show that the polymerase chain reaction for MDV and ALV-J env using DNA from feather tips was more effective for diagnosis of naturally infected commercial chickens than using the liver and spleen.
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Affiliation(s)
- Irit Davidson
- Division of Avian and Fish Diseases, Kimron Veterinary Institute, P.O. Box 12, Bet Dagan 50250, Israel.
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Borenshtain R, Davidson I. Marek's disease virus genome separation from feather tip extracts by pulsed field gel electrophoresis. J Virol Methods 2002; 101:169-74. [PMID: 11849695 DOI: 10.1016/s0166-0934(01)00434-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Marek's disease virus is an oncogenic herpes virus of poultry that is highly cell associated. In the infected tissues and tumors the virus replicates in a low copy number. The propagation and dissemination of the virus takes place at the feather follicle epithelium, where the viral genome is produced in high copy number. As the viral genome is a large circular DNA molecule (200 kbp), pulsed field gel electrophoresis was used for separation of the viral genome directly from the infected chicken. DNA was extracted from tumors or feather tips by the phenol:chloroform technique or by low melting agar technique. It was found that feathers, being the site of virus productive replication, are useful for separation of free Marek's disease virus DNA from in vivo infections.
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Affiliation(s)
- Rinat Borenshtain
- Division of Avian Diseases, Kimron Veterinary Institute, P.O. Box 12, 50250, Bet Dagan, Israel
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M. F. Islam AF, Walkden-Brown SW, Burgess SK, Groves PJ. Marek's disease in broiler chickens: Effect of route of infection and herpesvirus of turkey-vaccination status on detection of virus from blood or spleen by polymerase chain reaction, and on weights of birds, bursa and spleen. Avian Pathol 2001; 30:621-8. [DOI: 10.1080/03079450120092116] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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