| Summary: | 碩士 === 國立成功大學 === 醫學工程研究所碩博士班 === 95 === Helicobacter pylori, H. pylori's global prevailance rate is over fifty percent .patients with duodenal ulcer, DU or gastric cancers, GC are highly related to H. pylori infection. The WHO classifies H. pylori as the first part of carcinogen. Recent findings discover that different sickening factors result in different pathological presentation. The exact and quick classification of H. pylori can provide the doctors with accurate information to apply appropriate treatment.Conventional methods could provide H. pylori infection result in 4 hr. However, it can not further identify the species.Nonetheless, the procedures are relatively time-consuming. It is often weeks before accurate results can be obtained. In this research, a dielectrophoretic (DEP) technique has been applied to trapping H. pylori. And then we go to Raman spectroscopy, Raman spectrum’s scattering mechanism can be used to analyze molecular structure of bacteria and be applied to identification of H. pylori species.
This study has two parts; (1) we use MEMS Fabrication to make the 3D chip which was constructed by two electrode chips with one at the top, the other at the bottom and a fluidic channel sandwiched between to avoid electric field attenuation. The electrode design of circular holes array can increase trapping efficiency. In the 20 mM PBS solution at 20 Vp-p and 300 kHz, H. pylori were trapped successfully by nDEP force. (2) We use Raman spectroscopy to set up H. pylori Raman spectra. BabA protein expression can be identified by 1002-1003 cm-1、1200-1400 cm-1 and 1500-1700 cm-1 Raman shift of H. pylori Raman spectra. For practical conditions, real samples usually contain not only one kind of bacteria species. So that, we set up S. aureus, E. faecium, H. pylori and E. coli Raman spectra and use PCA and HCA methods to execute classification of bacteria. And then, we also establish 11GC and 9DU H. pylori Raman spectra successfully. According to qualitative analysis results, in 1365-1373 cm-1, H. pylori Raman spectra of GC patient and DU patient accounts for 82.2% and 22.2% respectively. On the side, we choose 1200-1250 cm-1 Raman shift (BabA protein part Raman shift ) of 20 H. pylori Raman spectra to execute HCA. The 20 H. pylori Raman spectra can be categorized in two groups. One group has eight GC and two DU. Another group has seven DU and three GC. At last, we combine Raman scattering technique with DEP chip for identification of H. pylori#238. However, the Raman singnal of H. pylori#238 is so weak by glass fluorescence.
This research can distinguish H. pylori with BabA protein difference from others and can tell the differnce between H. pylori and other pathogen on the spectrum. And find the Raman shift GC and DU differ in .We can increase the difference between GC and DU from the Raman shift. This method if go together with improvement of chip system can not only apply to patients’ H. pylori infection inspection, but also identify H. pylori to see if it lead to GC or DU. So this system takes short inspection time and can give us accurate results.
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