Ellie Harrison

This fully funded PhD position at the University of Sheffield, offered through the BBSRC Yorkshire Bioscience Doctoral Training Partnership (YBDTP), investigates the role of plant protection products (PPPs) as accidental drivers of antimicrobial resistance (AMR) in agriculture. AMR is a growing global health threat, and farms are recognized as significant environmental reservoirs for resistant bacteria, which can enter food chains and water systems. The project addresses the emerging issue of increased use of recycled waste products in agriculture, which often contain antibiotics and resistant microbes. While regulations focus on input contamination, recent evidence suggests that post-entry processes in soil may be even more critical. Notably, PPPs like glyphosate may select for AMR through cross-resistance or by enhancing horizontal gene transfer, potentially driving the spread of resistance genes in agricultural environments. The research will explore cross-resistance mechanisms between PPPs and antibiotics, monitor soil microbial community responses using sequencing and soil chemistry analyses, and assess how different PPP treatment regimes interact with low-level antibiotic contamination to influence resistance evolution. The project employs advanced techniques in microbiology, experimental evolution, molecular genetics, genome sequencing, bioinformatics, and environmental chemistry. Students will join a collaborative, interdisciplinary research group at the interface of molecular and evolutionary microbiology, soil science, and sustainable agriculture, with opportunities for professional development and an internship at FERA. The YBDTP provides a supportive, inclusive environment and encourages applications from diverse backgrounds. The studentship covers a four-year period, including a tax-free stipend, research costs, and tuition fees at the UK rate. International applicants are eligible for a limited number of full studentships. Applicants should have or expect at least an upper second-class honours degree in a relevant science or mathematics field. The application deadline is 7 January 2026, and the process includes shortlisting and interviews. For more information, visit the YBDTP website or contact the supervisors.

This fully funded PhD position is part of the BBSRC Yorkshire Bioscience Doctoral Training Partnership (YBDTP), a collaborative programme uniting leading bioscience research institutions across Yorkshire and Teesside. The project, based at the University of Sheffield's School of Biosciences, focuses on predicting the evolution of the healthcare-associated pathogen Clostridioides difficile in response to phage therapy. C. difficile is a major cause of illness and mortality worldwide, with its resilience attributed to its ability to form spores that withstand most chemical treatments. Current antibiotic treatments are increasingly ineffective, often leading to relapse and disruption of the gut microbiome. Phage therapy, which uses natural bacterial viruses to treat infections, presents a promising alternative, but its application to spore-forming pathogens like C. difficile is novel and potentially unpredictable. This project aims to understand the evolutionary dynamics of C. difficile during phage treatment, which is critical for developing effective future therapeutics. The research will involve real-time evolutionary experiments, genome sequencing, and molecular biology techniques to track the evolution of C. difficile populations with and without sporulation capabilities in the presence of phages. It will also examine how phages themselves evolve when co-cultured with different C. difficile populations under varying environmental conditions. The training provided will cover experimental design, sterile microbiological techniques, genome sequencing, bioinformatics, and molecular biology methods such as cloning and targeted mutagenesis. The interdisciplinary nature of the programme prepares students for a wide range of careers in bioscience research and beyond. The supervisory team, led by Dr Ellie Harrison and Dr R Fagan, is committed to providing tailored support and fostering an inclusive research environment. The position is open to UK, EU, and international students with at least an upper second-class honours degree (or equivalent) in a relevant science or mathematics discipline. The studentship covers a tax-free stipend at the UKRI rate, research costs, and tuition fees at the UK rate, with a limited number of full studentships available for exceptional international candidates. Applicants must meet the host university's entry and English language requirements. The application deadline is 7 January 2026, and candidates should submit an expression of interest form via the YBDTP website. Shortlisted applicants will be invited for interview, and successful candidates must complete their PhD within four years. The YBDTP is dedicated to recruiting outstanding scientists from all backgrounds and encourages applications from underrepresented groups in science.