The resistance of Pseudomonas aeruginosa to preservatives and detergents used in industrial formulations
PhD Research
Funding:
The full studentship (fees and stipend) is available to UK or EU students who have been resident in the UK for at least three years. Other EU participants may receive a fees only award.
Applicants capable of self-funding (UK, EU and international) are also welcome to apply.
Project details:
Principal Supervisor: Dr. Eshwar Mahenthiralingam
Second Supervisor: Prof. Andrew Weightman
Unilever Supervisor: Dr. Denise Donoghue
CASE Partner: Unilever Research and Development UK
Detergents and preservatives are widely used in the toiletries industry to prevent microbial contamination. However, intrinsically resistant environmental bacteria such as Pseudomonas aeruginosa may occasionally survive in products, leading to disruptive plant cleansing and recalls. Little is known about the preservative resistance of P. aeruginosa and how it survives in the presence of both detergents and preservatives. This studentship will aim to develop better strategies for the prevention of industrial contamination by P. aeruginosa as follows:
Aim 1. Understanding the diversity P. aeruginosa strains associated with industrial contamination. Random Amplified Polymorphic DNA fingerprinting (RAPD) and multilocus sequencing typing (MLST) will be applied to P. aeruginosa contamination isolates to build an understanding of whether there is a commonality in their genotype or source.
Aim 2. Resistance mechanisms of P. aeruginosa in the presence of detergents and preservatives. The preservative and detergent resistance of contamination isolates will be examined using growth inhibition, killing, and biofilm assays. The ability of selected low- and high-resistance isolates to adapt to product formulations will also be determined.
Aim 3. Cultivation-independent methods to identify low numbers of P. aeruginosa. Highly sensitive DNA- and RNA-amplification methods will be developed to detect P. aeruginosa in raw materials and pin point manufacturing processes that are susceptible to contamination.
Aim 4. Testing of novel preservation methods. A range of compounds have been recently shown to inhibit bacterial efflux and biofilm formation, and these will be tested on P. aeruginosa contaminants to see if the facilitate better product preservation.