BBSRC Institute Strategic Programme: Microbes and Food Safety

Lead Research Organisation: University of Cambridge
Department Name: Veterinary Medicine

Abstract

The Microbes and Food Safety (MFS) ISP will provide an understanding of how microbial threats, such as pathogens and spoilage-causing bacteria, evolve and interact to affect food safety and develop strategies to reduce their impact on health and the economy. We take for granted that most of the food we eat in the UK is free from the risk of microbial pathogens but the Food Standards Agency (FSA) estimates that around 2.4 million cases of microbial foodborne illness occur every
year, costing in excess of £9 billion. There is also an economic threat of food waste through spoilage, increasing retail costs; up to 25% of food spoilage is due to the action of microbes. Our mission is to reduce human foodborne illness through improved food safety and to reduce waste due to food spoilage. To do so, we will address key food safety questions in three Themes: 1) what and where are the microbial threats in foods? 2) What are the factors associated with the survival and success of microbial threats? 3) How can we use this information to improve food safety and reduce food
waste?

Throughout this programme, we will focus on key organisms and issues of strategic importance for food safety, in which we will exploit and further develop our demonstrable expertise. These are Campylobacter, Salmonella, Listeria, Pseudomonas, antimicrobial resistance (AMR) and the identification of emerging microbial threats through the use of metagenome sequencing. As microbial threats such as pathogens and spoilage-causing bacteria exist as complex microbial communities
across the food chain, we focus not only on the key organisms of interest, but we will also study the other microbes present which may support their survival or persistence.

In Theme 1, MICROBIAL THREATS FROM FOODS IN ESTABLISHED AND EVOLVING FOOD SYSTEMS, we will identify what microbial threats are present in our food - particularly newer food types. Our aim is to understand how microbial threats spread and cause disease or food spoilage by studying the genetic diversity and dynamics of gene flow within populations of foodborne bacteria. In particular we will assess evolving microbial threats from foods associated with shifts in consumer preference, trading relationships and climate change.

In Theme 2, MICROBIAL SURVIVAL IN ESTABLISHED AND EVOLVING FOOD SYSTEMS, we will define the factors associated with the survival and success of microbial threats. Our aim is to understand microbial survival and adaptation better by understanding the lifestyle of the bacteria present, e.g. biofilms, community associations and/or metabolism without growth. To do this we will use our specialised core services, including informatics, sequencing and microscopy to investigate samples taken from throughout the food chain and also from human clinical samples.

In Theme 3, FLEXIBLE CAPABILITIES TO REDUCE FOOD SAFETY THREATS AND RESPOND TO EMERGING NATIONAL NEEDS, we will use the data generated in the first two themes to improve food safety and reduce food waste. We will work with our stakeholders within QIB, academia, government and industry to apply the scientific evidence derived from our fundamental research to improve the evaluation of future risk and to inform the control of threats to food safety and resilience. Our capability will remain flexible so that we can respond quickly to unexpected emerging national needs as required.

Our aim with this programme of work is, with our established stakeholders, to improve the production of safe and nutritious foods and reduce loss of food from spoilage through the delivery of scientific knowledge and acting as a knowledge and training hub for microbial food safety.

Technical Summary

This project represents The University of Cambridge contribution to the delivery of the following Institute Strategic Programme Grant: BBSRC Institute Strategic Programme: Microbes and Food Safety, BB/X011011/1.

Cambridge will contribute to genomics work with Campylobacter as follows:

In 2.1.1 we will use our transposon mutant libraries in different Campylobacter species and strains to perform TraDIS to investigate the genes required to survive different stresses and combinations of stresses. We will investigate individual genes through the generation of defined deletion mutants and complemented mutants. We will use our novel CRISPR interference method to study the effect of repressing these genes.

In 2.1.2 we will use our transposons with outward facing promoters of different strengths combined with RNAseq and imaging to investigate Campylobacter survival and morphology changes when the bacteria are exposed to different biocides and antibacterial agents.

In 2.2.1 we will use TraDIS and imaging to study how Campylobacter survives in a model domestic environment. We will investigate the effects of different stresses on bacterial morphology and biofilm formation in both a single-species biofilm as well as a mixed-species community.

In 2.2.3 we will use HiC that we developed, combined with TraDIS and imaging to investigate how Campylobacter survives in mixed-species biofilms exposed to different food chain stresses.

In 2.2.4 we will support researchers at QIB by integrating our experimental data with genome scale metabolic models to model the metabolic pathways required for survival under different stress conditions.

In 2.3.1 we will use bacteriology, TraDIS and imaging to investigate how different species and strains of Campylobacter grow and survive on media prepared using emerging food products.

In 2.3.2 we will use bacteriology and imaging to screen and characterise selected polyphenols and AMPs against Campylobacter species and strains.