
Dr Denise Marston
Academic and research departments
School of Veterinary Medicine, Faculty of Health and Medical Sciences, Infection and immunity research theme.About
Biography
After graduating from the University of Leicester, UK in 1994 with a BSC (Hons) in Microbiology I began my scientific career at the Institute for Animal Health (Compton, UK). Whist at Compton, I was involved in elucidating the genetic factors responsible for resistance to Marek’s Disease in chickens and was seconded to the Pirbright Institute to assist in Foot and Mouth Disease outbreak in 2001.
In 2004, I joined the Virology Department at APHA (Animal and Plant Health Agency) in Weybridge, embarking on a research and diagnostic career focussing on viral zoonoses including rabies. During this time, I completed a PhD investigating the viral genetic elements responsible for host species transmission in lyssaviruses, achieving a prize for the best PhD thesis in 2017 by ‘La Foundation Méditerranée Infection’. As part of my studies, I pioneered the utilisation of Whole Genome Sequencing (WGS) to investigate the global diversity of lyssaviruses and was fortunate to discover and characterise two novel lyssaviruses.
I have harboured a passion for teaching others and valued the opportunity to provide in situ training of viral diagnostic techniques, including PCR and sequencing in countries such as Azerbaijan and Tajikistan. In 2020, I became the project manager for a cross-agency project to implement WGS to investigate the spread of bovine TB in cattle throughout GB.
2021 is a significant year for me beginning a new journey at the Vet School here at Surrey University. I am excited to bring the experience and knowledge I have and focus on teaching the next generation of Vets.
Areas of specialism
My qualifications
News
In the media
Teaching
I teach on the BVMSci (Hons) Veterinary Medicine and Science course.
I teach on the following modules:
VMS 2003: Foundations of Disease Three: Pathology of the Integument and Alimentary Systems
VMS 2009: Foundations of Disease Nine: General Pathology and Concepts of Infectious Disease
BMS3074: Animal Infectious Diseases
Publications
Background: The recommended screening of rabies in `suspect' animal cases involves testing fresh brain tissue. The preservation of fresh tissue however can be difficult under field conditions and formalin fixation provides a simple alternative that may allow a confirmatory diagnosis. The occurrence and location of histopathological changes and immunohistochemical (IHC) labelling for rabies in formalin fixed paraffin embedded (FFPE) canine brain is described in samples from 57 rabies suspect cases from Sri-Lanka. The presence of Negri bodies and immunohistochemical detection of rabies virus antigen were evaluated in the cortex, hippocampus, cerebellum and brainstem. The effect of autolysis and artefactual degeneration of the tissue was also assessed. Results: Rabies was confirmed in 53 of 57 (93%) cases by IHC. IHC labelling was statistically more abundant in the brainstem. Negri bodies were observed in 32 of 53 (60.4%) of the positive cases. Although tissue degradation had no effect on IHC diagnosis, it was associated with an inability to detect Negri bodies. In 13 cases, a confirmatory Polymerase chain reaction (PCR) testing for rabies virus RNA was undertaken by extracting RNA from fresh frozen tissue, and also attempted using FFPE samples. PCR detection using fresh frozen samples was in agreement with the IHC results. The PCR method from FFPE tissues was suitable for control material but unsuccessful in our field cases. Conclusions: Histopathological examination of the brain is essential to define the differential diagnoses of behaviour modifying conditions in rabies virus negative cases, but it is unreliable as the sole method for rabies diagnosis, particularly where artefactual change has occurred. Formalin fixation and paraffin embedding does not prevent detection of rabies virus via IHC labelling even where artefactual degeneration has occurred. This could represent a pragmatic secondary assay for rabies diagnosis in the field because formalin fixation can prevent sample degeneration. The brain stem was shown to be the site with most viral immunoreactivity; supporting recommended sampling protocols in favour of improved necropsy safety in the field. PCR testing of formalin fixed tissue may be successful in certain circumstances as an alternative test.
A brain homogenate derived from a rabid dog in the district of Tojiko-bod, Republic of Tajikistan, was applied to a Flinders Technology Associates (FTA) card. A full-genome sequence of rabies virus (RABV) was generated from the FTA card directly without extraction, demonstrating the utility of these cards for readily obtaining genetic data.
Lyssaviruses are an important genus of zoonotic viruses which cause the disease rabies. The United Kingdom is free of classical rabies (RABV). However, bat rabies due to European bat lyssavirus 2 (EBLV-2), has been detected in Daubenton’s bats (Myotis daubentonii) in Great Britain since 1996, including a fatal human case in Scotland in 2002. Across Europe, European bat lyssavirus 1 (EBLV-1) is commonly associated with serotine bats (Eptesicus serotinus). Despite the presence of serotine bats across large parts of southern England, EBLV-1 had not previously been detected in this population. However, in 2018, EBLV-1 was detected through passive surveillance in a serotine bat from Dorset, England, using a combination of fluorescent antibody test, reverse transcription-PCR, Sanger sequencing and immunohistochemical analysis. Subsequent EBLV-1 positive serotine bats have been identified in South West England, again through passive surveillance, during 2018, 2019 and 2020. Here, we confirm details of seven cases of EBLV-1 and present similarities in genetic sequence indicating that emergence of EBLV-1 is likely to be recent, potentially associated with the natural movement of bats from the near continent