Identification of putative pan-streptococcal vaccine targets

Streptococci cause significant economic and stock losses in the agriculture, aquaculture and have a serious impact on human health. These key threats from the continued intensification of food production are driven by the growing human:cattle:swine:fish interface and intensification of these livestock sectors. Antibiotic control of disease is becoming less feasible due to growing resistance and the threat of gene transfer within this zoonotic pathogen and alternative control strategies are urgently required. Limited strain, prevalence and sequence information exists for zoonotic Streptococcus and functional characterisation of these strains will provide key virulence related information for potential future control-based strategies.
Identification of the key components of bacteria that are involved in the infection process will allow the development of alternative therapies that prevent transmission. Alternately, these components may be incorporated into diagnostic tests to identify those strains naturally carried that are more likely cause infection, allowing a more targeted approach for treatment in those situations where transmission leading to disease is more likely. Either approach would greatly reduce the incidence of streptococcal infection in humans and livestock and thus reduce mortality associated with this disease.
This project will characterise genes/proteins essential for pan-streptococcal pathogenesis in humans, fish and cattle using vast archive of random mutagenesis high throughput sequencing data which have been generated in the Streptococcal Research Group (SRG) at SVMS. Individual bacterial mutant pools have be generated for representative strains using the pGh9:ISS1 insertional mutagenesis system, and analysed using the new bespoke laboratory and bioinformatic analysis programme we have developed called PIMMS V2. PIMMS V2 will be used to map insertions within the bacterial genomes and identify conditionally important / essential sequences that will be translated to metabolic pathways and biochemical processes for further comparative analysis. Producing information that describes a pan streptococcal essential genome and/or conditionally important genome and metabolic/ biochemical pathways and processes against which new disease control strategeies could be based.
The project will initially complete a pangenome analysis of 8 target streptococcal genomes (Streptococcus uberis, iniae, suis, agalactiae, pneumoniae, garviae and dysgalactiae) and incorporate a complete phenotypic pangenome analysis using the existing PIMMS data available leading to the identification of putative pan-streptococcal targets. Additional characterisation of these targets will take place in the laboratory using mutant banks held by SRG, to assess if the putative targets do infer a growth inhibiting effect. The overall output for the project will be a experimentally confirmed data analysis pipeline which will work with the existing PIMMS pipeline to incorporate multiple datasets, producing targets for future larger grant proposal in vaccine development.