Transcriptomic analysis of Clostridioides difficile grown in a biologically relevant growth medium

Abstract

Clostridioides difficile Infection (CDI) is a known healthcare acquired disease and significant source of antibiotic-associated diarrhoea (AAD), reported to be responsible for up to a third of recorded instances worldwide. Most of the research conducted into how C. difficile causes disease is carried out in artificial laboratory media, limiting insight into how this pathogen responds to the environment in which it causes disease i.e. the large intestine. The overall aim of this study was to construct a faecal water model to study the transcriptome of C. difficile 630 in order to characterise the molecular mechanisms underpinning pathogenesis within the organism. We hypothesised that understanding how C. difficile functions in a more biologically relevant setting would uncover mechanisms at work that could not be determined with the use of normal laboratory media by developing an in-vitro model to determine growth characteristics and the transcriptional profile of C. difficile 630 and the mutant strains Derm, dnaK and spo0A. We have contributed significantly within this thesis to the current understanding of C. difficile 630 and many of the processes involved in pathogenesis by providing a deeper understanding of how the transcriptome of C. difficile 630 alters in response to faecal water highlighting that important molecular processes are not being picked up in studies that employ basic laboratory growth media. The impact of the faecal water growth environment on C. difficile is clear with significant expressional changes observed in sporulation, motility, virulence factors and an important role for regulatory sRNAs in these processes. We have therefore provided a more realistic indication of how this organism may respond in the presence of human gut constituents whilst underscoring the regulatory effect FW has on gene expression in C. difficile.

Date of Award	Feb 2021
Original language	English
Supervisor	Nigel Ternan (Supervisor), Barry O'Hagan (Supervisor) & Geoffrey Mc Mullan (Supervisor)