Isolation of environmental Bacillus spp. encoding bacteriocins with novel antiC. difficile activity
Publication Date
December 15, 2022
Creator
Abstract
The emergence of antibiotic resistant, hypervirulent strains of the nosocomial pathogen Clostridioides difficile, coupled with increased concerns over the physiological impact of traditional broad-spectrum antibiotics on human health has led to an increased demand for alternative therapies. Bacteriocins are proteinaceous toxins produced by bacteria that kill other bacteria and their antimicrobial activity makes them an attractive potential alternative therapy to antibiotics. This study isolated two members of the B. subtilis species complex from porcine faeces that displayed potent anti-C. difficile activity against a range of C. difficile ribotypes: B. velezensis B18 and B subtilis 50B. Genome mining of these strains highlighted their incredible antimicrobial potential with them encoding nine and seven antimicrobial biosynthetic clusters respectively. Of these highlighted antimicrobials, multiple bacteriocins were thought to be responsible for the anti-C. difficile activity seen from the strains. Attempts to produce recombinant candidate bacteriocins highlighted a key issue in bacteriocin research: the lack of dedicated recombinant bacteriocin production workhorses. Part purification and characterisation of the anti-C. difficile compounds from the strains tentatively implies a novel activity against C. difficile from the lantibiotic amyloliquecidin, in addition to revealing a novel non-functional subunit that could be used to generate a semi-synthetic lantibiotic. Additionally, this study suggests a novel anti-C. difficile activity of the sactibiotic subtilosin A, which has never been described before. In addition to potentially highlighting the presence of other anti-C. difficile peptides produced by B. subtilis 50B overlooked by in silico mining methods.
Item Type
ethesis
Thesis Type
PhD
Supervisors
Subjects (LC)
Associated Schools / Departments
School of Life Sciences
eprints ID
69542
UoN Repository URI
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Yasmin McLaughlin Thesis BBSRC 2021 - 14274756.pdf
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Full-text
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