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https://ptsldigital.ukm.my/jspui/handle/123456789/500217Full metadata record
| DC Field | Value | Language |
|---|---|---|
| dc.contributor.advisor | Asmat Ahmad, Assoc. Prof. Dr. | - |
| dc.contributor.author | Merriam Ghadhanfar Alwan Hussain (P79486) | - |
| dc.date.accessioned | 2023-10-13T09:39:58Z | - |
| dc.date.available | 2023-10-13T09:39:58Z | - |
| dc.date.issued | 2018-01-06 | - |
| dc.identifier.other | ukmvital:110776 | - |
| dc.identifier.uri | https://ptsldigital.ukm.my/jspui/handle/123456789/500217 | - |
| dc.description | Antibiotic resistance and biofilm formation among oral microbiota has constituted an increasing Global health challenges, and limited information is available in Malaysia. The aims of this study were to disclose the prevalence of antibiotics resistance bacteria among selected oral microbial species and to develop an electrochemical DNA biosensor for rapid and specific detection of selected antibiotic resistance gene. A total of 72 samples were collected, 21, 31 and 20 from saliva, teeth and necrotic roots canals respectively. After cultivating aerobically or anaerobically, 267 bacterial isolates were isolated. In general, among 267 total isolates, 16.2% were identified as Enterococcus sp. and it's considered as the most prevalence genus. To screen the isolates according to its biofilm formation ability, three methods were used for that. These methods were Congo red agar method (CRA), tube method (TM) and Microtiter plate method (MTP). The results showed that the percentages of strong biofilm formation isolates for each method were 11.9%, 27.7% and 39% for CRA, TM and MTP respectively. Overall, 104 isolates were considered as strong biofilm former and then their antibiotic resistance ability were tested. Multi antibiotics resistance index values greater than 0.2 indicate high-risk source of contamination where antibiotics are often used, our results showed that the highest MAR index was among necrotic roots canals isolates (0.82) followed by teeth (0.71) and saliva (0.69). According to the isolates genera, Enterococcus sp. showed the highest MAR index among the isolates, which its record 0.97, 0.96, 0.89 for the isolates from saliva, necrotic roots canals and teeth respectively. Depending on the above data, Enterococcus sp. were chosen to continue for further studies on its virulence factors (Hemolysin, gelatinase, protease, lipase, DNase and cytotoxic activity). As a result of the screening steps, 9 isolates were confirmed as Enterococcus faecalis by using 16S rRNA gene. All the E. faecalis isolates underwent for the detection of the presence of biofilm formation, antibiotics resistance and virulence factors genes by using multiplex PCR technique. RAPD and ERIC PCR techniques were employed to study the extent of convergence between isolates from different sources. Plasmid extraction was done to investigate the relationship between the presence of plasmids and the antibiotics resistance ability. Finally, an electrochemical DNA biosensor based on hollow silica microsphere-gold (Si-Au) nanocomposite-modified screen-printed carbon electrode for the detection of vancomycin resistance gene (VanA) was developed. The results showed high selectivity of the VanA probe with the complementary and non-complementary DNA targets. The DNA biosensor response towards various cDNA concentrations was linearly patterned from 1×10-12 μM to 1 μM. Eighteen samples were subjected to test the ability of DNA biosensor for the detection of the presence of Van A gene. These samples were 3 extracted DNA, 3 PCR products and 3 broth samples of 3 isolates of Enterococcus faecalis (S1, H 85 and M2). The DNA biosensor was applied to investigate the VanA gene in nine real samples (3 from saliva and 6 from marine water). It was concluded that the VRE DNA biosensor showed high potential to serve as a point of use device for detection of the presence of vancomycin resistance E. faecalis bacteria., 'Certification of Master's/Doctoral Thesis' is not available,Ph.D. | - |
| dc.language.iso | eng | - |
| dc.publisher | UKM, Bangi | - |
| dc.relation | Faculty of Science and Technology / Fakulti Sains dan Teknologi | - |
| dc.rights | UKM | - |
| dc.subject | Drug resistance. | - |
| dc.subject | Enterococcus | - |
| dc.subject | Universiti Kebangsaan Malaysia -- Dissertations | - |
| dc.subject | Dissertations, Academic -- Malaysia | - |
| dc.title | Antibiotic resistance and virulence factors screening of bacteria isolated from saliva, teeth and necrotic root canals and rapid detection of enterococcus faecalis vancomycin resistance gene with a DNA biosensor | - |
| dc.type | Theses | - |
| dc.format.pages | 262 | - |
| dc.identifier.callno | QR177.H837 2019 tesis | - |
| dc.identifier.barcode | 004156(2019) | - |
| Appears in Collections: | Faculty of Science and Technology / Fakulti Sains dan Teknologi | |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| ukmvital_110776+SOURCE1+SOURCE1.0.PDF Restricted Access | 1.06 MB | Adobe PDF |  View/Open |
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