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dc.contributorDepartment of Health Technology and Informaticsen_US
dc.creatorTsang, Chun Ho-
dc.identifier.urihttps://theses.lib.polyu.edu.hk/handle/200/7587-
dc.languageEnglishen_US
dc.publisherHong Kong Polytechnic University-
dc.rightsAll rights reserveden_US
dc.titleInvestigation the anti-microbiale effects of Rhizoma Zingiberis Recens (RZR) and Rhizoma Atractylodis (RA) on Escherichia coli (E.coli), Extended spectrum beta lactamase (ESBL) E. coli, Staphylococcus aureus (SA) and Methicillin-resistant Staphylococcus aureus (MRSA)en_US
dcterms.abstractIntroduction: Herbal or plant products are potential natural choices for treating bacterial infections. They have the advantage of fewer side effects, and are less harmful to humans compared with synthetic Western medicines. Objective: This study proposes using the track dilution method to determine the antimicrobial effect of Rhizoma Zingiberis Recens (RZR) and Rhizoma Atractylodis (RA) on Escherichia coli (E. coli), Extended-spectrum beta lactamase (ESBL) E. coli, Staphylococcus aureus (SA) and methicillin-resistant Staphylococcus aureus (MRSA), with various concentrations of RZR and RA. We investigated 10 clinical isolates of ESBL E. coli, MRSA, E. coli ATCC 25922 and SA ATCC 25923. Methods: Bacteria strains used in the project were identified through Gram staining, biochemical tests and antibiotic susceptibility tests. Growth curves of each strain of SA, MRSA, E. coli and ESBL E. coli were established to estimate the time of each bacteria stain reached the mid-log phase. Standard curve of each strain of SA, MRSA, E. coli and ESBL E. coli were established to determine the initial number of bacteria present in the nutrient broth by measuring the optical density of the broth. The antimicrobial effect of RA and RZR on bacterial strains was determined through track dilution method. Propidium iodide (PI) staining was done to investigate the inhibitory mechanism of RA or RZR on the bacteria. The stained bacterial cells indicated the existence of membrane inhibition.en_US
dcterms.abstractResults: The result in a 99.9% reduction in the initial inoculum (i.e., a 3-log10 reduction in colony-forming units per milliliter) on subculture usually regarded as a significant reduction of CFU. We conducted the Kruskal-Wallis test and Dunn multiple-comparison tests using Prism software and analyzed the results. RA and RZR leaded to 1 to 3 log10 reduction in CFU/ml at low concentration of RA and RZR (i.e., 50mg/ml) on SA ATCC 25923 and 10 strains of MRSA compared with the water control after 24-hour incubation. The reduction of CFU/ml increased with the increment of RA and RZR concentration treatment. RA (i.e., 350mg/ml) leaded to a maximum of 4 to 5 log10 reduction in CFU/ml and RZR (i.e., 75 to 100mg/ml) leaded to a maximum of 7 to 9 reduction in CFU/ml. Only RZR (i.e., 500mg/ml) leaded to a maximum of 3 to 4 log10 reduction in CFU/ml on 2 strains of ESBL E. coli. The PI staining results indicated that RA inhibited all MRSA and SA strains through membrane inhibition, whereas only 5 strains of MRSA were inhibited by RZR through membrane inhibition. Conclusion: Our results indicated that RA and RZR exerted an inhibitory effect on all SA and MRSA strains, and that this effect was dose dependent. It had an RZR inhibitory effect only on 2 strains ESBL E. coli.en_US
dcterms.extentxiv, 92 leaves : illustrations ; 30 cmen_US
dcterms.isPartOfPolyU Electronic Thesesen_US
dcterms.issued2014en_US
dcterms.educationalLevelAll Masteren_US
dcterms.educationalLevelM.Sc.en_US
dcterms.LCSHHerbs -- Therapeutic use -- Testing.en_US
dcterms.LCSHMedicine, Chinese.en_US
dcterms.LCSHEscherichia coli.en_US
dcterms.LCSHBeta lactamases.en_US
dcterms.LCSHEnterobacteriaceae.en_US
dcterms.LCSHStaphylococcus aureus.en_US
dcterms.LCSHHong Kong Polytechnic University -- Dissertationsen_US
dcterms.accessRightsrestricted accessen_US

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Please use this identifier to cite or link to this item: https://theses.lib.polyu.edu.hk/handle/200/7587