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https://ptsldigital.ukm.my/jspui/handle/123456789/499859Full metadata record
| DC Field | Value | Language |
|---|---|---|
| dc.contributor.advisor | Asmat Ahmad, Prof. Madya Dr. | - |
| dc.contributor.author | Khansa Mohammed Younis (P68178) | - |
| dc.date.accessioned | 2023-10-13T09:35:31Z | - |
| dc.date.available | 2023-10-13T09:35:31Z | - |
| dc.date.issued | 2017-04-13 | - |
| dc.identifier.other | ukmvital:85334 | - |
| dc.identifier.uri | https://ptsldigital.ukm.my/jspui/handle/123456789/499859 | - |
| dc.description | The aim of this study was to determine the potential of secondary metabolites of Streptomyces as bacterial anti biofilm and anti-quorum sensing agents against biofilm forming uropathogens. From a total of 100 isolates from urinary catheters, six isolates were selected as target pathogens based on multi-antibiotic resistance and strong biofilm formation on sterile urinary catheters. The actinomycetes used in this study were from Marine Microbiology Lab, UKM and Iraqi's isolates. A total of 114 actinomycetes were screened for antibacterial against the target pathogens and anti quorum sensing using Serratia marcescens SMJ-11as a reporter strain. One isolate designated as sdLi displayed broad spectrum anti biofilm and strongest anti-quorum sensing activity against target pathogens. This isolate was identified as Streptomyces rochei based on morphological and biochemical characterisation followed by phylogenetic analysis of 16S rRNA gene. Biofilm development was reduced by 92% for Pseudomonas aeruginosa, 90% for Candida albicans, 78% for Klebsiella pneumoniae, 77% for Enterobacter cloacae, 73% for Proteus mirabilis, and 57% for Escherichia coli after treatment using lyophilised sdLi culture supernatant. Spread plate test showed that the sdLi supernatant interfered only with the biofilm forming ability of the target bacteria and the cells were viable after treatment. SEM and light microscopy observations of Foley urinary catheter and cover glass exposed to the target pathogens showed that there was a lack of biofilm formation and the presence of only a few single cells after treatment. Minimum inhibitory concentration assay (MIC) of ethyl acetate extract against P. mirabilis UCBa4 showed that sub-MIC concentrations attenuated biofilm formation, studied virulence factors and decreased pH value of the test medium. Reverse transcription-PCR (RT-PCR) analysis of non-treated Proteus mirabilis UCB4 showed there was an amplification with clear bands of expression products of the QS-regulated genes (LuxS, Pmr, RsbA, ureR and 16sRNA) during 16 and 18 h incubation periods. Only faint bands were visible from the treated cells. SdLi ethyl acetate crude extract was purified using flash column chromatography column and thin-layer chromatography profile demonstrate the presence of six fractions, of which KHA4 and KHA5 were the most bioactive in anti-quorum sensing activity. Fraction KHA5 was identified as Bis (2-ethylhexyl) phthalate using gas chromatography-mass spectrometry analysis. Bioassay-guided fractionation, TLC-bioautography and Fourier transform infrared spectrophotometry showed that fraction KHA4 contained three compounds, of which compounds KHA4-2 and KHA4-3 were strongest in anti-quorum sensing activity. Nuclear magnetic resonance and liquid chromatography-mass spectrometry analyses showed that KHA4-2 is N-(2-hydroxy tetrahydrofuran-3-yl) undecanamide and KHA4-3 is (S)-4-hydroxy-2-(3 oxotridecanamido) butanoic acid. Results of this study showed that S. rochei sdLi is a very promising candidate for the development of anti quorum sensing and anti biofilm forming compounds against uropathogens.,Certification of Master's/Doctoral Thesis" is not available | - |
| dc.language.iso | eng | - |
| dc.publisher | UKM, Bangi | - |
| dc.relation | Faculty of Science and Technology / Fakulti Sains dan Teknologi | - |
| dc.rights | UKM | - |
| dc.subject | Streptomyces | - |
| dc.subject | Bacterial anti biofilm | - |
| dc.subject | Anti-quorum sensing | - |
| dc.subject | Urinary catheter | - |
| dc.subject | Dissertations, Academic -- Malaysia | - |
| dc.title | Anti-biofilm forming and anti-quorum sensing activities of streptomyces against selected pathogens from urinary catheter | - |
| dc.type | Theses | - |
| dc.format.pages | 195 | - |
| dc.identifier.barcode | 002581(2017) | - |
| Appears in Collections: | Faculty of Science and Technology / Fakulti Sains dan Teknologi | |
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| File | Description | Size | Format | |
|---|---|---|---|---|
| ukmvital_85334+SOURCE1+SOURCE1.0.PDF Restricted Access | 329.29 kB | Adobe PDF |  View/Open |
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