Please note that Professor Maiden has been appointed to serve as a Senior Proctor at the University of Oxford from March 2019 – March 2020.
He will still be monitoring his zoo.ox.ac.uk emails during this time period, but response time might be longer due to the Senior Proctor role’s commitments. Please contact his PA if you have urgent queries, or do not receive a response within a week.
Professor of Molecular Epidemiology
- Fellow of Hertford College
- Fellow of The Royal College of Pathologists, The Academy of Medical Sciences, The American Academy of Microbiology and The Royal Society of Biology
My group studies the population biology and evolution of bacterial pathogens, with the objective of translating the insights obtained into benefits for human health. Our work focuses on two globally important pathogens, Neisseria meningitidis and Campylobacter jejuni, although we work on other pathogens through a variety of collaborations. We use a ‘Population Genomics’ approach, which combines data on genome sequence diversity with a variety of types of phenotypic information assembled from large representative bacterial isolate collections. Making extensive use of collaborations within and outside the Department, we explore these data with a range of analysis approaches including: epidemiological studies; dynamic modelling; and phylogenetic and genealogical investigations.
N. meningitidis, the meningococcus, and its close relatives Neisseria gonorrhoeae and Neisseria lactamica, are obligately associated with humans but have different relationships with them (1). N. lactamica very rarely if ever causes disease, N. gonorrhoeae is a global cause of sexually transmitted disease while some, but not all, meningococci are a high-profile cause of septicaemia and meningitis (2). Unravelling genomic differences among these bacteria helps to reveal why such similar bacteria can have such dissimilar clinical effects. We are also interested in the impact of mass vaccination on meningococcal populations (3) and are using the molecular epidemiology of meningococci to develop novel vaccination approaches.
The genus Campylobacter contains two of the most common bacterial enteric pathogens of humans world wide, C. jejuini and Campylobacter coli. These multi-host zoonotic pathogens comprise closely related yet diverse genotypes that exhibit a high degree of host association (4). Transmission studies show that genotypes are transmitted within host populations and that human disease is primarily caused by the genotypes circulating among food animals, especially chickens, rather than other types that may be present on farms (5). There are some data suggesting that agriculture has introduced recent ecological changes affecting the speciation of these bacteria (4). These studies have application in controlling the spread of human campylobacteriosis.
Additional Information: I currently hold an honorary Chair in the Department of Biology, University of Cardiff
Microevolution of Campylobacter jejuni during long-term infection in an immunocompromised host.
Barker CR. et al, (2020), Sci Rep, 10
Pan-GWAS of Streptococcus agalactiae Highlights Lineage-Specific Genes Associated with Virulence and Niche Adaptation.
Gori A. et al, (2020), mBio, 11
Relationships among streptococci from the mitis group, misidentified as Streptococcus pneumoniae.
Sadowy E. et al, (2020), Eur J Clin Microbiol Infect Dis
Agricultural intensification and the evolution of host specialism in the enteric pathogen Campylobacter jejuni.
Mourkas E. et al, (2020), Proc Natl Acad Sci U S A
Localized Hypermutation is the Major Driver of Meningococcal Genetic Variability during Persistent Asymptomatic Carriage.
Green LR. et al, (2020), mBio, 11