Biofilm infections have been the focus of much attention and are associated with both tissue infections and medical-devices. In this study, conventional staining techniques combined with a reproducible biofilm preparation protocol were optimised for the study of single species bacterial and fungal biofilms in 96 well plates. The antibiofilm activities of the antimicrobial peptide LL-37 and its truncated mimetics KE-18 and KR-12 were evaluated and it was shown that LL-37 had significant biofilm prevention activities against Candida albicans, Staphylococcus aureus and Escherichia coli. On the other hand, KE-18, showed efficacy in biofilm prevention assays against S. aureus but not E. coli, whereas KR-12 showed no antibiofilm activities against any of the species studied. In view of the species diversity that is acknowledged to be important in biofilm related infections, a molecular method was established to facilitate the study of inter kingdom biofilm formation. Study of inter kingdom biofilms consisting of fungal and bacterial species (namely C. albicans along with one of the respiratory pathogens: Pseudomonas aeruginosa, S. aureus, or E. coli) showed that C. albicans favoured the growth of E. coli. and S. aureus, but not P. aeruginosa in dual-species biofilms. In experiments to determine the antibiofilm activities of conventional antifungal drugs it was apparent that conventional drugs were effective against single species C. albicans biofilms but that there was loss of antifungal efficacy against dual species biofilms. In assessing the antibiofilm properties of a novel family of peptide mimics, known as peptoids, antibiofilm efficacy was noted against both single and dual species biofilms. It is concluded that peptoids represent a novel class of antimicrobials that merit further study for the treatment of clinically relevant biofilms.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:707820 |
| Date | January 2016 |
| Creators | Luo, Yu |
| Contributors | Lundy, Fionnuala |
| Publisher | Queen's University Belfast |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://pure.qub.ac.uk/portal/en/theses/novel-methods-for-the-quantification-and-treatment-of-clinically-relevant-biofilms(4c5be507-6717-4512-bc38-ee312369cc3c).html |
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