Biocides and the emergence of antimicrobial resistance.

The 2024/25 application process is now closed

Visit the MRC DTP/CASE at LSTM pages for further information.

We are increasingly using  relatively cheap, easily accessible, biocides in our everyday cleaning regimens, both in and around our home and office and on ourselves. The increasing use of biocides will inevitably lead to increasingly high selective pressure for bacteria which evolve reduced susceptibility or resistance to these compounds. This project, in collaboration with our industrial project partner Unilever, will aim to determine resistance potential of industry standard active biocidal compounds and associated mechanisms of resistance, linkage with antibiotic resistance genes, fitness of resistance and cross-resistance to other unrelated compounds. We will also determine any collateral-sensitivity towards other antimicrobial agents that result from biocide resistance generation and whether resistance is likely able to undergo horizontal gene transfer to other bacteria. To do this we will use microbiological, molecular and metagenomic investigations supported with genome sequencing and bioinformatic analysis of resistant strains. We will also assess the effect of combinations of different biocides as a strategy to minimise the emergence of resistance and lower the overall usage of individual compounds. Results will feed into industry policy discussions via Unilever on a paradigm shift from killing microbes to managing microbial communities.

Where does the project lie on the Translational Pathway?

T1 – Basic Research

T4 Practice to Policy / Population

Expected Outputs

Publications on the emergence of resistance to biocides are expected. There is a large scope for the direction of the project and each avenue would produce publishable data.
The generation of the first data package comparing different biocides could be adopted as a standard reference for industry when developing new active components of biocides and therefore the project would have impact beyond the PhD.
Policy input into usage, combinations and concentrations which would minimise the emergence of resistance is also expected.
Further funding will be sought with Unilever to develop the work on combination usage as the PhD progresses.

Training Opportunities

The student would receive training in microbiology, molecular biology and bioinformatics, the industrial partner would provide the student with key insights into policy implantation within the biocide field and industrial experience within a leading biocide producer.

Skills Required

A keen interest in microbiology and antimicrobial resistance, a willingness to spend time with our industrial partner as part of their PhD.

Key Publications associated with this project

Tansirichaiya S, Reynolds LJ, Cristarella G, Wong LC, Rosendahl K, Roberts AP. Reduced Susceptibility to Antiseptics Is Conferred by Heterologous Housekeeping Genes. Microb Drug Resist. 2018 Mar;24(2):105-112. doi: 10.1089/mdr.2017.0105.

Podnecky NL, Fredheim EGA, Kloos J, Sørum V, Primicerio R, Roberts AP, Rozen DE, Samuelsen Ø, Johnsen PJ. Conserved collateral antibiotic susceptibility networks in diverse clinical strains of Escherichia coli. Nat Commun. 2018 Sep 10;9(1):3673. doi: 10.1038/s41467-018-06143-y.

Seier-Petersen MA, Jasni A, Aarestrup FM, Vigre H, Mullany P, Roberts AP, Agersø Y. Effect of subinhibitory concentrations of four commonly used biocides on the conjugative transfer of Tn916 in Bacillus subtilis. J Antimicrob Chemother. 2014 Feb;69(2):343-8. doi: 10.1093/jac/dkt370.

Ciric L, Ellatif M, Sharma P, Patel R, Song X, Mullany P, Roberts AP. Tn916-like elements from human, oral, commensal streptococci possess a variety of antibiotic and antiseptic resistance genes. Int J Antimicrob Agents. 2012 Apr;39(4):360-1. doi: 10.1016/j.ijantimicag.2011.12.007.

Ciric L, Mullany P, Roberts AP. Antibiotic and antiseptic resistance genes are linked on a novel mobile genetic element: Tn6087. J Antimicrob Chemother. 2011 Oct;66(10):2235-9. doi: 10.1093/jac/dkr311.