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Asfor AS, Wakeley PR, Drew TW, Paton DJ. Recombinant pestivirus E2 glycoproteins prevent viral attachment to permissive and non permissive cells with different efficiency. Virus Res 2014; 189:147-57. [PMID: 24874197 DOI: 10.1016/j.virusres.2014.05.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 05/02/2014] [Accepted: 05/07/2014] [Indexed: 10/25/2022]
Abstract
Bovine viral diarrhoea virus (BVDV) is an economically important animal pathogen, which like other pestiviruses has similar molecular biological features to hepaciviruses, including human Hepatitis C virus. The pestivirus E2 glycoproteins are the major target for virus-neutralising antibodies, as well as playing a role in receptor binding and host range restriction. In this study, recombinant E2 glycoproteins (rE2) derived from three different pestivirus species were examined for their inhibitory effects on pestivirus infectivity in cell culture. Histidine-tagged rE2 glycoproteins of BVDV type 2 strain 178003, BVDV type 1 strain Oregon C24V and CSFV strain Alfort 187 were produced in Spodoptera frugiperda insect cells and purified under native conditions. The ability of rE2 glycoprotein to inhibit the infection of permissive cells by both homologous and heterologous virus was compared, revealing that the inhibitory effects of rE2 glycoproteins correlated with the predicted similarity of the E2 structures in the recombinant protein and the test virus. This result suggests that the sequence and structure of E2 are likely to be involved in the host specificity of pestiviruses at their point of uptake into cells.
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Affiliation(s)
- A S Asfor
- Virology Department, Animal Health and Veterinary Laboratories Agency (Weybridge), Addlestone, Surrey, KT15 3NB, UK; The Pirbright Institute, Ash Road, Pirbright, Woking GU24 0NF, Surrey, UK.
| | - P R Wakeley
- Virology Department, Animal Health and Veterinary Laboratories Agency (Weybridge), Addlestone, Surrey, KT15 3NB, UK
| | - T W Drew
- Virology Department, Animal Health and Veterinary Laboratories Agency (Weybridge), Addlestone, Surrey, KT15 3NB, UK
| | - D J Paton
- The Pirbright Institute, Ash Road, Pirbright, Woking GU24 0NF, Surrey, UK
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2
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Jeffries CL, Mansfield KL, Phipps LP, Wakeley PR, Mearns R, Schock A, Bell S, Breed AC, Fooks AR, Johnson N. Louping ill virus: an endemic tick-borne disease of Great Britain. J Gen Virol 2014; 95:1005-1014. [PMID: 24552787 DOI: 10.1099/vir.0.062356-0] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
In Europe and Asia, Ixodid ticks transmit tick-borne encephalitis virus (TBEV), a flavivirus that causes severe encephalitis in humans but appears to show no virulence for livestock and wildlife. In the British Isles, where TBEV is absent, a closely related tick-borne flavivirus, named louping ill virus (LIV), is present. However, unlike TBEV, LIV causes a febrile illness in sheep, cattle, grouse and some other species, that can progress to fatal encephalitis. The disease is detected predominantly in animals from upland areas of the UK and Ireland. This distribution is closely associated with the presence of its arthropod vector, the hard tick Ixodes ricinus. The virus is a positive-strand RNA virus belonging to the genus Flavivirus, exhibiting a high degree of genetic homology to TBEV and other mammalian tick-borne viruses. In addition to causing acute encephalomyelitis in sheep, other mammals and some avian species, the virus is recognized as a zoonotic agent with occasional reports of seropositive individuals, particularly those whose occupation involves contact with sheep. Preventative vaccination in sheep is effective although there is no treatment for disease. Surveillance for LIV in Great Britain is limited despite an increased awareness of emerging arthropod-borne diseases and potential changes in distribution and epidemiology. This review provides an overview of LIV and highlights areas where further effort is needed to control this disease.
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Affiliation(s)
- C L Jeffries
- Animal Health and Veterinary Laboratories Agency - Weybridge, Woodham Lane, Addlestone, Surrey KT15 3NB, UK
| | - K L Mansfield
- Animal Health and Veterinary Laboratories Agency - Weybridge, Woodham Lane, Addlestone, Surrey KT15 3NB, UK
| | - L P Phipps
- Animal Health and Veterinary Laboratories Agency - Weybridge, Woodham Lane, Addlestone, Surrey KT15 3NB, UK
| | - P R Wakeley
- Animal Health and Veterinary Laboratories Agency - Weybridge, Woodham Lane, Addlestone, Surrey KT15 3NB, UK
| | - R Mearns
- Animal Health and Veterinary Laboratories Agency - Penrith, Merrythought, Calthwaite, Penrith CA11 9RR, UK
| | - A Schock
- Animal Health and Veterinary Laboratories Agency - Lasswade, Pentlands Science Park, Penicuik, Midlothian EH26 0PZ, UK
| | - S Bell
- Animal Health and Veterinary Laboratories Agency -Shrewsbury Investigation Centre & Laboratory, Kendal Road, Harlscott, Shrewsbury, Shropshire SY1 4HD, UK
| | - A C Breed
- Animal Health and Veterinary Laboratories Agency - Weybridge, Woodham Lane, Addlestone, Surrey KT15 3NB, UK
| | - A R Fooks
- University of Liverpool, Department of Clinical Infection, Microbiology and Immunology, Liverpool, Merseyside L69 7BE, UK.,Animal Health and Veterinary Laboratories Agency - Weybridge, Woodham Lane, Addlestone, Surrey KT15 3NB, UK
| | - N Johnson
- Animal Health and Veterinary Laboratories Agency - Weybridge, Woodham Lane, Addlestone, Surrey KT15 3NB, UK
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3
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North SE, Wakeley PR, Mayo N, Mayers J, Sawyer J. Development of a real-time PCR to detect Streptococcus equi subspecies equi. Equine Vet J 2013; 46:56-9. [PMID: 23663066 DOI: 10.1111/evj.12088] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 03/13/2013] [Indexed: 11/29/2022]
Abstract
REASONS FOR PERFORMING STUDY Infection with Streptococcus equi subspecies equi (S. equi) is endemic in the UK. A proportion of horses serve as long-term carriers and act as a reservoir of infection. Detection of these persistently infected horses is difficult using standard culture techniques owing to a lack of sensitivity and overgrowth by contaminating bacteria. In addition, differentiation of this causative bacterium from the closely related S. equi zooepidemicus has made the development of reliable and accurate diagnostic tests difficult. OBJECTIVE To develop and validate a sensitive and specific real-time PCR assay to detect S. equi and to compare the results with traditional culture techniques. STUDY DESIGN Retrospective cross-sectional study. METHODS The assay was validated using a panel of 92 samples from suspected clinical cases of strangles. These were cultured using microbial techniques and tested using the S. equi real-time PCR. The results of the 2 methods were compared, and the diagnostic sensitivity and specificity of the real-time PCR were calculated. The real-time PCR was tested for cross-reactivity with horse commensal bacteria, and the efficiencies and limits of detection were established. RESULTS The assay had a diagnostic sensitivity of 95% and specificity of 86%. No cross-reactivity was observed with any of the bacterial species tested, including S. equi zooepidemicus. The assay detected as few as 3 gene copies. CONCLUSION The assay is fast, sensitive and specific and will detect S. equi DNA directly from a crude extract of clinical material on a swab. POTENTIAL RELEVANCE This assay could aid in the rapid detection of subclinical shedders of S. equi, enabling quicker treatment and helping to limit the spread of strangles in equine populations.
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Affiliation(s)
- S E North
- Technology Transfer Unit, Specialist Scientific Support Department, Animal Health and Veterinary Laboratories Agency, Addlestone, Surrey, UK
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4
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Jones RM, Ellis RJ, Cox WJ, Errington J, Fuller C, Irvine RM, Wakeley PR. Development and validation of RT-PCR tests for the detection and S1 genotyping of infectious bronchitis virus and other closely related gammacoronaviruses within clinical samples. Transbound Emerg Dis 2011; 58:411-20. [PMID: 21477114 PMCID: PMC7169724 DOI: 10.1111/j.1865-1682.2011.01222.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Two tests were developed that allow the detection and genotyping of infectious bronchitis virus (IBV) and other closely related gammacoronaviruses. The first test employs a one-step, reverse transcription-polymerase chain reaction (RT-PCR) assay in which the amplification is monitored in real time using a TaqMan(®) probe. This real-time RT-PCR test was used to examine a panel of field samples and its performance compared to virus isolation in embryonated fowls' eggs. A total of 323 field samples were tested; 176 samples were positive using the real-time RT-PCR method, but only three were positive by virus isolation. Sequencing was used to confirm the positive real-time RT-PCR results for a subset of samples. The test is suitable for swabs and post-mortem samples and has been shown to be highly sensitive and specific. The second test, a genotyping method, was developed for identification of the strain of IBV present in field samples based on nucleotide variations within the gene encoding the S1 subunit of the surface spike (S) glycoprotein. This method was developed to provide a tool to inform vaccination decisions and for ongoing surveillance to detect new and emerging strains of IBV within the UK. The performance of the test was evaluated using laboratory isolates of IBV and field samples. Both tests are suitable for use in a high-throughput diagnostic laboratory.
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Affiliation(s)
- R M Jones
- Veterinary Laboratories Agency, Weybridge, New Haw, Addlestone, Surrey, UK.
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5
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Hoffmann B, Freuling CM, Wakeley PR, Rasmussen TB, Leech S, Fooks AR, Beer M, Müller T. Improved safety for molecular diagnosis of classical rabies viruses by use of a TaqMan real-time reverse transcription-PCR "double check" strategy. J Clin Microbiol 2010; 48:3970-8. [PMID: 20739489 PMCID: PMC3020878 DOI: 10.1128/jcm.00612-10] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Revised: 04/29/2010] [Accepted: 08/18/2010] [Indexed: 11/20/2022] Open
Abstract
To improve the diagnosis of classical rabies virus with molecular methods, a validated, ready-to-use, real-time reverse transcription-PCR (RT-PCR) assay was developed. In a first step, primers and 6-carboxyfluorescien-labeled TaqMan probes specific for rabies virus were selected from the consensus sequence of the nucleoprotein gene of 203 different rabies virus sequences derived from GenBank. The selected primer-probe combination was highly specific and sensitive. During validation using a sample set of rabies virus strains from the virus archives of the Friedrich-Loeffler-Institut (FLI; Germany), the Veterinary Laboratories Agency (VLA; United Kingdom), and the DTU National Veterinary Institute (Lindholm, Denmark), covering the global diversity of rabies virus lineages, it was shown that both the newly developed assay and a previously described one had some detection failures. This was overcome by a combined assay that detected all samples as positive. In addition, the introduction of labeled positive controls (LPC) increased the diagnostic safety of the single as well as the combined assay. Based on the newly developed, alternative assay for the detection of rabies virus and the application of LPCs, an improved diagnostic sensitivity and reliability can be ascertained for postmortem and intra vitam real-time RT-PCR analyses in rabies reference laboratories.
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Affiliation(s)
- B Hoffmann
- Institute of Diagnostic Virology, Südufer 10, 17493 Greifswald-Insel Riems, Germany.
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6
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Affiliation(s)
- P. R. Wakeley
- Veterinary Laboratories Agency - Weybridge; New Haw Addlestone Surrey KT15 3NB
| | - J. Errington
- Veterinary Laboratories Agency - Weybridge; New Haw Addlestone Surrey KT15 3NB
| | - D. Squirrell
- Enigma Diagnostics, Building 224, DstL Porton Down Wiltshire SP4 OJQ
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7
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Foster AP, Houlihan MG, Holmes JP, Watt EJ, Higgins RJ, Errington J, Ibata G, Wakeley PR. Bovine viral diarrhoea virus infection of alpacas (Vicugna pacos
) in the uk. Vet Rec 2007; 161:94-9. [PMID: 17652435 DOI: 10.1136/vr.161.3.94] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Three alpacas (Vicugna pacos) aged two to 22 months with a history of illthrift and diarrhoea were examined postmortem, and tissues were collected for histology, including immunohistochemical labelling for pestivirus antigen, virus isolation and TaqMan reverse transcriptase-pcr assay. Blood samples from two clinical cases and the remaining herd members were tested for bovine viral diarrhoea virus (bvdv) antibody by serum neutralisation, antigen detection and pcr assay. The three affected alpacas were positive for bvdv by pcr of splenic tissue and/or heparinised blood. Non-cytopathic bvdv was isolated from several tissues and plasma of two of the alpacas. dna sequencing and phylogenetic analysis of the viral genome from the pcr product showed that the bvdv was of subgenotype 1b. Immunohistochemical examination of brain tissue was positive in two cases, consistent with a persistent infection. bvdv antibodies were detected in 16 of 25 clinically unaffected alpacas. There was no evidence of persistent infection in the in-contact animals. The source of the infection was not determined.
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Affiliation(s)
- A P Foster
- Veterinary Laboratories Agency (VLA) - Shrewsbury, Kendal Road, Harlescott, Shrewsbury, Shropshire SY1 4HD
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8
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West DM, Sprigings KA, Cassar C, Wakeley PR, Sawyer J, Davies RH. Rapid detection of Escherichia coli virulence factor genes using multiplex real-time TaqMan® PCR assays. Vet Microbiol 2007; 122:323-31. [PMID: 17336470 DOI: 10.1016/j.vetmic.2007.01.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2006] [Revised: 01/26/2007] [Accepted: 01/30/2007] [Indexed: 10/23/2022]
Abstract
Three multiplex real-time TaqMan PCR assays were developed for the detection of Escherichia coli virulence factor genes in veterinary samples. Target virulence factors chosen were the fimbriae K88 (F4), K99 (F5), F41, F17, F18 and 987p (F6) and the toxins LT, STa and CDT IV. Detection of genes coding GAD were included in each assay as an internal control. These assays allow rapid identification of virulence factor genes using identical cycling conditions on an Mx3000Ptrade mark real-time PCR machine with the capacity to test up to 20 strains for 9 virulence genes in 1h.
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Affiliation(s)
- D M West
- Technology Transfer Unit, Veterinary Laboratories Agency, Woodham Lane, New Haw, Addlestone, Surrey, UK
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9
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Wakeley PR, Errington J, Hannon S, Roest HIJ, Carson T, Hunt B, Sawyer J, Heath P. Development of a real time PCR for the detection of Taylorella equigenitalis directly from genital swabs and discrimination from Taylorella asinigenitalis. Vet Microbiol 2006; 118:247-54. [PMID: 16971068 DOI: 10.1016/j.vetmic.2006.08.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2005] [Revised: 08/02/2006] [Accepted: 08/07/2006] [Indexed: 11/30/2022]
Abstract
A discriminatory real time PCR for the detection of Taylorella equigenitalis, the causative agent of contagious equine metritis (CEM), and the related species T. asinigenitalis was developed for the direct examination of genital swabs. The 112bp amplicons produced from the two species were discriminated from each other using TaqMan probes labelled with different fluorophores. The TaqMan PCR was shown to be specific for the 16S ribosomal DNA of the two species of taylorella and did not cross-hybridise with the 16S ribosomal DNA of other bacteria tested. Direct amplification from genital swabs was shown to be equally sensitive to that of culture methods. Prevalence in a sample set from The Netherlands was shown to be equivalent to that demonstrated by culture. A companion real time PCR that amplified a fragment of the 16S rDNA gene of equine commensal bacteria was developed to ensure bacterial DNA was extracted from swab material supplied for testing. The use of a rapid and reliable real time PCR for the organism causing CEM should aid the control of this disease.
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Affiliation(s)
- P R Wakeley
- Technology Transfer Unit, Biotechnology Department, Veterinary Laboratories Agency, New Haw, Addlestone, Surrey, UK.
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10
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Wakeley PR, Johnson N, McElhinney LM, Marston D, Sawyer J, Fooks AR. Development of a real-time, differential RT-PCR TaqMan assay for lyssavirus genotypes 1, 5 and 6. Dev Biol (Basel) 2006; 126:227-36; discussion 326-7. [PMID: 17058499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
A number of RT-PCR methods have been reported for the detection of rabies and rabies-related viruses. Here, a single, closed tube, non-nested RT-PCR TaqMan assay to distinguish between Classical rabies virus and European bat lyssaviruses 1 and 2 in real time is described. The TaqMan assay is rapid, sensitive, specific and allows for the genotyping of unknown isolates concomitant with the RT-PCR. It can be applied quantitatively and the use of an internal control enables the quality of the isolated template to be assessed. The efficiency and dynamic range of the PCR has been established using isolated viral RNA and cloned control template. Comparative performance of the TaqMan assay against other diagnostic methodologies for the detection of rabies virus has been determined and the assay validated against a panel of archival samples and virus of unknown genotype from both Germany and the Sudan. Despite sequence heterogeneity between the different genotypes in the N-gene, a universal forward and reverse primer set have been designed allowing simplification of previously described assays. Rapid genotyping of two recent EBLV2 cases in the U.K. in Daubenton's bats and a recently imported human case of rabies has been performed using this test.
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Affiliation(s)
- P R Wakeley
- Technology Transfer Unit, Biotechnology Department, Veterinary Laboratories Agency, Weybridge, Surrey, United Kingdom.
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11
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Wakeley PR, Johnson N, McElhinney LM, Marston D, Sawyer J, Fooks AR. Development of a real-time, TaqMan reverse transcription-PCR assay for detection and differentiation of lyssavirus genotypes 1, 5, and 6. J Clin Microbiol 2005; 43:2786-92. [PMID: 15956398 PMCID: PMC1151886 DOI: 10.1128/jcm.43.6.2786-2792.2005] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Several reverse transcription-PCR (RT-PCR) methods have been reported for the detection of rabies and rabies-related viruses. These methods invariably involve multiple transfers of nucleic acids between different tubes, with the risk of contamination leading to the production of false-positive results. Here we describe a single, closed-tube, nonnested RT-PCR with TaqMan technology that distinguishes between classical rabies virus (genotype 1) and European bat lyssaviruses 1 and 2 (genotypes 5 and 6) in real time. The TaqMan assay is rapid, sensitive, and specific and allows for the genotyping of unknown isolates concomitant with the RT-PCR. The assay can be applied quantitatively and the use of an internal control enables the quality of the isolated template to be assessed. Despite sequence heterogeneity in the N gene between the different genotypes, a universal forward and reverse primer set has been designed, allowing for the simplification of previously described assays. We propose that within a geographically constrained area, this assay will be a useful tool for the detection and differentiation of members of the Lyssavirus genus.
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Affiliation(s)
- P R Wakeley
- World Health Organization Collaborating Centre for the Characterization of Rabies and Rabies-Related Viruses, Department of Virology, Veterinary Laboratories Agency, Addlestone, United Kingdom.
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12
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13
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Cranwell MP, Jones JR, Wakeley PR. BVD virus type 2 in British cattle. Vet Rec 2005; 156:257-8. [PMID: 15751574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
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14
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Wakeley PR, Turner JLE, Ibata G, King DP, Sandvik T, Howard P, Drew TW. Characterisation of a type 2 bovine viral diarrhoea virus isolated from cattle in the UK. Vet Microbiol 2004; 102:19-24. [PMID: 15288923 DOI: 10.1016/j.vetmic.2004.05.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2003] [Revised: 04/26/2004] [Accepted: 05/10/2004] [Indexed: 11/29/2022]
Abstract
Two genotypes of bovine viral diarrhoea virus (BVDV) are recognised. Type 2 was first recognised when virulent strains caused significant losses among cattle in North America. Subsequently, BVDV type 2 has been found in many other countries, but recent studies have shown that only type 1 BVDV is circulating in the UK herds (sheep and cattle) with type 1a predominating. During routine genotyping of UK BVDV isolates, a type 2 isolate was identified. Phylogenetic analysis of the 5'-untranslated region of the viral genome showed it to be a BVDV type 2a, most similar to a low virulent US strain of BVDV type 2. Antigenic typing with a panel of monoclonal antibodies verified this classification. This is the first confirmed isolation of BVDV type 2 found circulating in the UK.
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Affiliation(s)
- P R Wakeley
- Veterinary Laboratories Agency-Weybridge, New Haw, Addlestone, Surrey KT15 3NB, UK.
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15
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Wakeley PR, Dorazi R, Hoa NT, Bowyer JR, Cutting SM. Proteolysis of SpolVB is a critical determinant in signalling of Pro-sigmaK processing in Bacillus subtilis. Mol Microbiol 2000; 36:1336-48. [PMID: 10931284 DOI: 10.1046/j.1365-2958.2000.01946.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SpoIVB is essential for intercompartmental signalling in the sigma(K)-checkpoint of Bacillus subtilis. SpoIVB is synthesized in the spore chamber and is the signal which activates proteolytic processing of pro-sigma(K) to its mature and active form sigma(K). We show here that SpoIVB is a serine peptidase of the SA clan. Expression of SpoIVB in Escherichia coli has shown that SpoIVB is able to self-cleave into at least three discrete products, and in vitro studies have shown cleavage in trans. Autoproteolysis of SpoIVB is tightly linked to the initiation of the two developmental functions of this protein, signalling of pro-sigma(K) processing and a yet, uncharacterized, second function which is essential for the formation of heat-resistant spores. In B. subtilis, SpoIVB is synthesized as a zymogen and is subject to two levels of proteolysis. First, autoproteolysis generating intermediate products, at least one of which is proposed to be the active form, followed by processing by one or more enzymes to smaller species. This could provide a mechanism for switching off the active SpoIVB intermediate(s) and suggests a similarity to other proteolytic cascades such as those found in blood coagulation.
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Affiliation(s)
- P R Wakeley
- School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey, UK
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16
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Abstract
Bacillus subtilis is currently used as an oral probiotic. We examined two commercial B. subtilis probiotic preparations, Enterogermina and Biosubtyl. Surprisingly, physiological and genetic characterization of the bacteria contained in each of these preparations has shown that neither contains B. subtilis.
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Affiliation(s)
- D H Green
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, United Kingdom
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17
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Wakeley PR, Rogers HJ, Rozycka M, Greenland AJ, Hussey PJ. A maize pectin methylesterase-like gene, ZmC5, specifically expressed in pollen. Plant Mol Biol 1998; 37:187-92. [PMID: 9620276 DOI: 10.1023/a:1005954621558] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Pectin methylesterase (PME) is responsible for the demethylation of pectin prior to pectin's degradation by the combined activities of polygalacturonase and pectate lyase. We have differentially screened a maize pollen cDNA library to detect cDNA clones whose genes are specifically expressed in pollen. One group of clones resulting from this screen showed similarity (between 18% and 41% identity) with plant and fungal PMEs. The full-length clone from this group, ZmC5, identifies a small gene family (at least 2 members) when used as a probe on genomic Southern blots. Northern analysis reveals that the ZmC5 transcript is expressed specifically in late pollen development. This tissue-specific gene expression programme is further confirmed in transgenic tobacco plants harbouring ZmC5 promoter/GUS chimeric gene constructs.
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Affiliation(s)
- P R Wakeley
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, UK
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18
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Abstract
We have compared the two-dimensional gel (2D gel) profiles of in vitro synthesised polypeptides from maize shoot with that of pollen, and the latter with that of germinated pollen. In the former comparison, extensive quantitative and qualitative differences in the polypeptides are apparent. We describe an increase in the abundance of the major cytoskeletal protein, alpha tubulin, in pollen compared to shoot. We also show that the electrophoretically separable alpha tubulin polypeptides in ungerminated pollen are not obviously post-translationally modified. In the comparison between the 2D gel profiles of the in vitro synthesised polypeptides from pollen and germinated pollen a number of notable differences are apparent, the possible origins of which are described.
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Affiliation(s)
- P J Hussey
- Department of Biochemistry, University of London, Egham, Surrey, UK
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Henney AM, Wakeley PR, Davies MJ, Foster K, Hembry R, Murphy G, Humphries S. Localization of stromelysin gene expression in atherosclerotic plaques by in situ hybridization. Proc Natl Acad Sci U S A 1991; 88:8154-8. [PMID: 1896464 PMCID: PMC52465 DOI: 10.1073/pnas.88.18.8154] [Citation(s) in RCA: 451] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The stromelysins are members of a family of extracellular matrix metalloproteinases. These enzymes may erode the connective tissue in atherosclerotic plaques, leading to fissuring and acute thrombotic events. Cell-specific stromelysin expression in human atherosclerotic plaques was studied by in situ hybridization and immunocytochemistry. Sections were taken from nine coronary arteries: eight with well-established plaques and one normal. Unambiguous signals were seen in five plaques, two were inconclusive, and the remaining sample was negative, as was the normal coronary artery. Stromelysin mRNA transcripts were localized to isolated individual cells, some of which were smooth muscle, in the plaque cap, intima, and adventitia, but not the media. Expression was also seen in large clusters of macrophages that contained intracellular lipid deposits. The isolated expression of stromelysin by smooth muscle cells may reflect local connective tissue remodeling associated with growth and the formation of the plaque, whereas the more extensive expression associated with macrophages may be of greater pathological significance, contributing to the destabilization of the extracellular matrix and eventual plaque rupture.
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Affiliation(s)
- A M Henney
- Arterial Diseases Unit, Charing Cross Sunley Research Centre, Hammersmith, London, England
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