Determining the molecular mode of action of HPC product preservatives and characterising antimicrobial resistance in problematic bacterial contaminant

Each year, millions of tonnes of home and personal care (HPC) products, including cleaning products, cosmetics and
toiletries are manufacturer globally. To keep these products free from microorganisms, industrial manufacturers add
antimicrobial preservatives. However, products occasionally become contaminated with microorganisms, the most
common of which are antimicrobial resistant bacteria which can also cause human infections.
The HPC industry is undergoing considerable change, needing to reduce the use of environmentally toxic preservatives,
consumer pressure to use natural and milder but less effective preservatives, and the urgent requirement to reduce
single-use plastic packaging. The changes are conducive to increased HPC product contamination, and a potential rise in
antimicrobial resistant (AMR) bacteria causing outbreaks of infection.
We have teamed up with Unilever Research & Development (Port Sunlight, UK) to offer a CASE PhD studentship aimed
at filling multiple knowledge gaps in relation to the use of preservatives and new multifunctional product ingredients.
Past collaborative PhD training between Cardiff University and Unilever has investigated a range of problematic
antimicrobial resistant bacteria including Burkholderia, Pseudomonas and Enterobacteriaceae. These species are
considered priorities in relation to the development of new HPC preservation strategies.
The proposed PhD will examine the mechanisms behind preservative mode of action and resistance in the priority
bacterial contaminants. This knowledge will provide industrial manufacturers with solutions to improve HPC
preservation and preventing the development of further antimicrobial resistance.
The project will specifically:
1. Use molecular and genomic techniques to understand how preservatives and multifunctional ingredients work to
suppress or kill bacteria, as well as how the industrial contaminant resist these important antimicrobials.
2. Monitor and identify priority contaminants causing manufacturing incidents using molecular methods including PCR,
whole genome sequencing and sequencing the entire DNA content of the industrial products
(metagenomic analysis).
3. Understand how large plasmids (called megaplasmids) specifically help priority contaminants survive the harsh
antimicrobial-rich conditions in HPC products