Overview

Our focus is to understand chronic and relapsing bacterial infections. We use various traditional microbiological techniques together with modern –omics approaches to determine the molecular systems that bacteria use to survive for prolonged periods of time under physical and chemical stresses. What is particularly interesting is that when infecting an anatomical niche, over a long time period, bacteria generate a diversity of cell types – it is these that enable survival against various antimicrobial processes. 

By creating steady-state growth conditions we can enable the broader bacterial cell types which may have decreased fitness; to be studied – these include biofilm cells, persister cells and Small Colony Variants (SCVs). Identifying and characterising these adaptive cell types is important for understanding chronic and relapsing infectious diseases. Our research investigates various pathogenic bacteria, commensal bacteria that do switch to a virulent type and the combinations of bacteria. 

RESEARCH PROJECTS:                 

Many bacterial species have a capacity to respond to antimicrobial processes and assaults by the production of any number of virulence factors (above; blue circles). Pathology that is due to bacterial infection is generally the result of the interaction between these factors and the host cells. There is also a very clear understanding that within a clonal population of bacterial cells there are a variety of cell types (phenotypic variants). This may include the Small Colony Variants (SCVs – above; pale green circles), persister cells (above; dark green circles) and biofilm cells (above; gold circles).

These cell types are quasi-dormant, they have limited expression of virulence factors and immune mediators and they have low metabolic activity and growth. There are inherently tolerant of antibiotics. They are very hard to clear from the site of infection and are the basis for chronic and relapsing infections.

Compounded with this is that often within the body there are pre-existing bacteria or other co-infecting pathogens. We have projects that study different bacterial species and their transition into an alternative lifestyle: such as Staphylococcus aureus, Moraxella catarrhalis, Haemophilus influenzae and Streptococcus pneumoninae.

We have used continuous culture techniques to follow the development of phenotypically diverse populations (as a mono-culture or within a community of bacterial species) and then to map the transcriptional, molecular and genetic events that define these changes in the population. This includes the transition to a biofilm and the dynamics of a multi-species biofilm. We are also interested in following the molecular genetics of the bacteria and the bacterial population as they adapt to their environment in laboratory scale evolution expierments.

       CURRENT STUDENT PROJECTS:

We have Honours Projects each year within the theme of the molecular microbiology of pathogenic bacteria during their response to stresses. The projects involve traditional microbiology, molecular biology and modern –omics techniques as well as cell biology (using human tissue culture techniques). Projects are designed around both fundamental, training and achievable tasks alongside extended goals. These projects are designed within the context of the current, developing research within the laboratory. The work is essential research, with a focus to combine with the bigger projects and therefore for scientific publications. The exact nature of the work can be discussed and actual projects described in the month or so leading into the start of the Honours year. 

Masters and PhD projects:

We welcome Masters or PhD students and can happily discuss the nature of such projects.