Spectrophotometric approaches to develop a bacteriophage based assay to identify pathogens of poultry

Chickens have been shown to carry a wide range of bacterial pathogens that can infect humans. The most important and prevalent of these pathogens are Clostridium perfringens, Salmonella spp, and Campylobacter jejuni,. Detecting what bacterial species the chickens carry is not straightforward and most tests rely on culture, ELISA or molecular approaches which all have problems with specificity and selectivity. Delay in identifying the pathogens, or misidentifying them can lead to the chickens receiving ineffective antibiotics, this has implications for bacterial carriage, animal welfare and the development of antibiotic resistance. The aim of this project is to develop a prototype phage based diagnostic tool that could be used by vets/farmers in order to establish the identity of bacterial pathogens that infect chickens in a quick and effective manner.

This project will exploit the specificity of interaction between bacteria and their specific bacteriophages. We will aim to identify phages for each of the major chicken pathogens, and label them, or their tail fibre proteins, with a unique detectable marker. This will be in conjunction with a specifically developed microfluidic device able to produce droplets. Biological samples will then be tested for the pathogens of interest will be passed through the device. If two phage reporters that infect one pathogen attach to a particular cell within a single droplet, there will be a specific co-localised signal unique to that pathogen. This signal will be detected and the pathogen identified with the use of spectroscopy. The development of this assay would have a significant impact on bacterial diagnosis for many situations, however the immediate aim is to address a current and real problem affecting the safety of the food chain, this research is a clear example of strong science which leads to a translational endpoint.