Caffeine as a novel quorum sensing inhibitor / Siti Nur Maisarah Norizan

Quorum sensing (QS) is a system used by bacteria to control the gene expression in response to cell density. QS involves in the regulation of variety bacterial physiological functions such as biofilm formation, pyocyanin production and swarming which has been recorded to contribute to bacterial p...

Full description

Bibliographic Details
Main Author: Siti Nur Maisarah, Norizan
Format: Thesis
Published: 2017
Subjects:
Online Access:http://studentsrepo.um.edu.my/9177/
http://studentsrepo.um.edu.my/9177/1/Siti_Nur_Maisarah_Norizan.pdf
http://studentsrepo.um.edu.my/9177/5/Siti_Nur_Maisarah_Norizan_%E2%80%93_Dissertation.pdf
_version_ 1848773856145178624
author Siti Nur Maisarah, Norizan
author_facet Siti Nur Maisarah, Norizan
author_sort Siti Nur Maisarah, Norizan
building UM Research Repository
collection Online Access
description Quorum sensing (QS) is a system used by bacteria to control the gene expression in response to cell density. QS involves in the regulation of variety bacterial physiological functions such as biofilm formation, pyocyanin production and swarming which has been recorded to contribute to bacterial pathogenesis. Therefore, QS would be an interesting target to attenuate pathogens for treating bacterial pathogenicity and infections. In this work, the anti-QS activity of caffeine; a natural occurring alkaloid found at varying quantities in seeds, leaves and fruits of some plants were tested against Chromobacterium violaceum CV026 and Pseudomonas aeruginosa PA01. Quantification assay on the violacein produced by C. violaceum CV026 showed that caffeine inhibited violacein synthesis in concentration dependent manner. In agreement to that, qualitative studies of C. violaceum CV026 showed the extent of violacein reduction is approximately 68% for caffeine applied at the concentration of 0.3mg/mL. Subsequently, this study also showed that caffeine inhibited swarming motility of P. aeruginosa PA01 as observed by the reduction of P. aeruginosa PA01 migration distance from the spot-inoculated centre on the swarming agar. In addition, caffeine also inhibited P. aeruginosa PA01 pyocyanin production. Qualitative study conducted on P. aeruginosa PA01 has confirmed that P. aeruginosa PA01 pyocyanin production was reduced up to 77% when treated with caffeine at 0.3mg/mL. To the best of our knowledge, this is the first documentation providing evidence on the presence of caffeine anti-quorum sensing activity. This study will allow caffeine to be explored as an alternative for anti-infective drug in future.
first_indexed 2025-11-14T13:49:03Z
format Thesis
id um-9177
institution University Malaya
institution_category Local University
last_indexed 2025-11-14T13:49:03Z
publishDate 2017
recordtype eprints
repository_type Digital Repository
spelling um-91772020-02-13T19:09:40Z Caffeine as a novel quorum sensing inhibitor / Siti Nur Maisarah Norizan Siti Nur Maisarah, Norizan Q Science (General) Quorum sensing (QS) is a system used by bacteria to control the gene expression in response to cell density. QS involves in the regulation of variety bacterial physiological functions such as biofilm formation, pyocyanin production and swarming which has been recorded to contribute to bacterial pathogenesis. Therefore, QS would be an interesting target to attenuate pathogens for treating bacterial pathogenicity and infections. In this work, the anti-QS activity of caffeine; a natural occurring alkaloid found at varying quantities in seeds, leaves and fruits of some plants were tested against Chromobacterium violaceum CV026 and Pseudomonas aeruginosa PA01. Quantification assay on the violacein produced by C. violaceum CV026 showed that caffeine inhibited violacein synthesis in concentration dependent manner. In agreement to that, qualitative studies of C. violaceum CV026 showed the extent of violacein reduction is approximately 68% for caffeine applied at the concentration of 0.3mg/mL. Subsequently, this study also showed that caffeine inhibited swarming motility of P. aeruginosa PA01 as observed by the reduction of P. aeruginosa PA01 migration distance from the spot-inoculated centre on the swarming agar. In addition, caffeine also inhibited P. aeruginosa PA01 pyocyanin production. Qualitative study conducted on P. aeruginosa PA01 has confirmed that P. aeruginosa PA01 pyocyanin production was reduced up to 77% when treated with caffeine at 0.3mg/mL. To the best of our knowledge, this is the first documentation providing evidence on the presence of caffeine anti-quorum sensing activity. This study will allow caffeine to be explored as an alternative for anti-infective drug in future. 2017-01 Thesis NonPeerReviewed application/pdf http://studentsrepo.um.edu.my/9177/1/Siti_Nur_Maisarah_Norizan.pdf application/pdf http://studentsrepo.um.edu.my/9177/5/Siti_Nur_Maisarah_Norizan_%E2%80%93_Dissertation.pdf Siti Nur Maisarah, Norizan (2017) Caffeine as a novel quorum sensing inhibitor / Siti Nur Maisarah Norizan. Masters thesis, University of Malaya. http://studentsrepo.um.edu.my/9177/
spellingShingle Q Science (General)
Siti Nur Maisarah, Norizan
Caffeine as a novel quorum sensing inhibitor / Siti Nur Maisarah Norizan
title Caffeine as a novel quorum sensing inhibitor / Siti Nur Maisarah Norizan
title_full Caffeine as a novel quorum sensing inhibitor / Siti Nur Maisarah Norizan
title_fullStr Caffeine as a novel quorum sensing inhibitor / Siti Nur Maisarah Norizan
title_full_unstemmed Caffeine as a novel quorum sensing inhibitor / Siti Nur Maisarah Norizan
title_short Caffeine as a novel quorum sensing inhibitor / Siti Nur Maisarah Norizan
title_sort caffeine as a novel quorum sensing inhibitor / siti nur maisarah norizan
topic Q Science (General)
url http://studentsrepo.um.edu.my/9177/
http://studentsrepo.um.edu.my/9177/1/Siti_Nur_Maisarah_Norizan.pdf
http://studentsrepo.um.edu.my/9177/5/Siti_Nur_Maisarah_Norizan_%E2%80%93_Dissertation.pdf