The Molecular Characterisation and Diagnostics Group focuses on the detection and characterisation of viruses causing Vesicular (blister) diseases of livestock:
- foot-and-mouth disease virus (FMDV)
- swine vesicular disease virus (SVDV),
- vesicular exanthema of swine virus (VESV) and
- vesicular stomatitis virus (VSV).
The main objectives of our research are to:
- develop and evaluate molecular diagnostic methods, based on the genetic material of the viruses.
- use gene sequencing data to trace the movement of FMDV on a worldwide scale and
- to understand at a molecular level those parts of FMDV that induce immune responses, including protective immunity.
Collectively our work underpins the activities of the FAO/OIE/CRL
Reference Laboratories for FMD and SVD .
MCD - Research
Real-time reverse transcription polymerase chain reaction (RT-PCR) methods ( using automated procedures) can achieve rapid and accurate diagnosis of the vesicular diseases of livestock. In comparison to established diagnostic methodologies (such as virus isolation and antigen ELISA), RT-PCR has been shown to be highly sensitive and specific. Furthermore, these molecular assays can detect viruses such as FMDV in a wide variety of sample types including vesicular epithelium e.g. tongue, serum, blood, milk, 'probang' fluids (scrapings from the oesophagus) and swabs. Our current research is directed towards improving and refining the performance of real-time RT-PCR as a diagnostic tool. We are also actively exploring novel formats in order to develop improved assays for detection of FMDV. These include microarrays and isothermal chemistries. We are particularly interested in developing mobile assay platforms that might achieve extremely rapid molecular diagnosis close to suspect cases of disease ('pen-side' tests).
Molecular Epidemiology
Molecular epidemiology has become an invaluable aid to monitor and control the spread of viruses (such as FMDV) on a global basis. Using RT-PCR, we routinely amplify and sequence the gene encoding the FMDV outer capsid polypeptide VP1. Phylogenetic reconstruction techniques are used to visualize the genetic relationships of field strains of FMDV with archived sequences of viruses previously tested in the reference laboratory. Our studies in Turkey and the Philippines have shown that FMDV newly introduced into a region (type A in Turkey and types O, A and C in the Philippines) may evolve very rapidly. However, viruses which are endemic (type O in Turkey) appear to evolve more slowly. In collaboration with other groups within and outside the IAH, we have conducted similar studies on two other picornaviruses, SVDV and encephalomyocarditis virus. Recently, in collaboration with the University of Glasgow, we have developed high-resolution tools (full genome sequencing methods) that allow us to reconstruct individual transmission events that occurred during the 2001 outbreak of FMD in the United Kingdom.
Antigenicity prediction tools
Vaccination is an important means to control FMD. However, this is constrained by the lack of cross-protection between the seven serotypes (O, A, C, Asia 1, SAT1, SAT2 and SAT3) of FMDV, as well as incomplete protection between some subtypes. We are developing new antigenicity prediction tools that will be used to select the most appropriate vaccine strains for use in the event of an FMD outbreak.
Publications
- Cottam, E.M., Haydon, D.T., Paton, D.J., Gloster, J., Wilesmith, J.W., Ferris, N.P., Hutchings, G.H., and King, D.P.
(2006).
Molecular epidemiology of the foot-and-mouth disease virus outbreak in the United Kingdom in 2001.
Journal of Virology 80: 11274?11282[Abstract].
- Dukes, J.D., King, D.P. and Alexandersen, S.
(2006).
Novel reverse transcription loop-mediated isothermal amplification (RT-LAMP) for rapid detection of foot-and-mouth disease virus.
Archives of Virology 151: 1093-1106[Abstract].
- King, D.P., Ferris, N.P., Shaw, A.E., Reid, S.M., Hutchings, G.H., Giuffre, A.C., Robida, J.M., Callahan, J.D., Nelson, W.M. and Beckham, T.R.
(2006).
Detection of foot-and-mouth disease virus: comparative diagnostic sensitivity of two independent real-time reverse transcription-polymerase chain reaction assays.
Journal of Veterinary Diagnostic Investigation 18: 93-97[Abstract].
- Knowles, N.J., Samuel, A.R., Davies, P.R., Midgley, R.J. and Valarcher, J.-F.
(2005).
Evolution and spread of a pandemic strain of foot-and-mouth disease virus serotype O.
Emerging Infectious Diseases 11: 1887-1893[Abstract].
- Reid, S.M., Parida, S., King, D.P., Hutchings, G.H., Shaw, A.E., Ferris, N.P., Zhang, Z., Hillerton, J.E. and Paton, D.J.
(2006).
Utility of automated real-time RT-PCR for the detection of foot-and-mouth disease virus excreted in milk.
Veterinary Research 37: 121-132.