Increased sensitivity of a PCR for detecting viable food borne pathogens | |
| Author | Kim Davin |
| Call Number | AIT Thesis no.FB-08-01 |
| Subject(s) | Polymerase chain reaction Foodborne diseases |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. FB-08-01 |
| Abstract | The limitation of a PCR for detecting food pathogens include the need for enriching the number of microorganism in the sample and its ability to discriminate between vibal and non viable cells. The aim of this research was find out optimum concentration of Zi(OH)₄ to facilitate immobilization and in the way concentrate food borne pathogens. The effect of enzyme DNase I and DNase II for detection viable food borne pathogens while breaking down DNA of dead cells was also studied. Food pathogens E.coli wild type, Listeria monocytogenes and Salmonella spp. were used in this research. The concentration of Zi(OH)₄ at 11.4 mM was evaluated as an optimum concentration based on its efficiency of immobilization and cell recoveries were above 95%. There were significant lower immobilization cell at lower concentrations of Zi(OH)₄ This optimum was used to concentrate the bacteria in 25 ml of sample, and at the highest sensitivity the conventional PCR could detect 10/\3 cells per 25 ml of media (TSBYE). On the other hand, there were no effect of DNase I and DNase II on the DNA presenting in both dead and live cells even increasing unit of DNase I and DNase II from 10 units to 30 units. In conclusion, concentration of Zi(OH)₄ was able to decrease double time from previous study to at 11.4 mM with more than 95% of immobilization efficiency. Though both form of DNases were effectively breaking down DNA samples, they were not able to penetrate into viable and non-viable whole cells. |
| Year | 2008 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ;no. FB-08-01 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Food Engineering and Bioprocess Technology (FB) |
| Chairperson(s) | Rakshit, Sudip Kumar; |
| Examination Committee(s) | Athapol Noomhorm ;Jayasuriya, H. P. W.; |
| Scholarship Donor(s) | Sweden Sida; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2008 |