| Author: | Chui, Chin-hung Andrew |
| Title: | Effect of pstC mutation of enterohaemorrhagic Escherichia coli O157:H7 on bacterial adhesion |
| Degree: | M.Sc. |
| Year: | 2012 |
| Subject: | Escherichia coli O157:H7 Hong Kong Polytechnic University -- Dissertations |
| Department: | Department of Health Technology and Informatics |
| Pages: | xii, 92 leaves : col. ill. ; 30 cm. |
| Language: | English |
| Abstract: | Enterohaemorrhagic Escherichia coli (EHEC) is a worldwide known food-borne pathogen that not only causes diarrhea but also haemolytic uremic syndrome with the shiga-toxin it produces. This was the first study to investigate the phenotypic effect of pst operon mutation on EHEC adhesion to cells, and intimin expression. The bacteria used in this study were wild-type and pstC-mutated EHEC O157:H7. The cell-line used for adhesion assay was HEp-2 cells. Wright's stain and fluorescent actin stain were used to visualize the bacterial adhesion and the 'attaching and effacing' (A/E) lesions by EHEC. The EHEC O157:H7 strains were grown in medium with or without additional phosphate. HEp-2 cell morphology and the abundance of adherent bacteria were scored. The results of this study showed there was statistically significant difference (P<0.05) in bacterial adhesion between the wild-type and pstC-mutated O157:H7. However, there was no statistical significant difference (P>0.05) between wild type O157 grown in medium with increased phosphate concentration, and wild type O157 grown in medium with normal phosphate concentration. Diffused adhesion on HEp-2 cells by EHEC O157 was observed for pstC-mutated O157 only regardless of phosphate concentration (P>0.05). Overall, the results of this study suggested that a mutation of pstC can increase EHEC adhesion to cells and inanimate surfaces. However, this study only investigated the effect of pstC mutation as well as phosphate concentration, in phenotypic expression of intimin and the adhesion of EHEC to HEp-2 cells. Therefore, genotypic expression must also be investigated to support the findings. |
| Rights: | All rights reserved |
| Access: | restricted access |
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| File | Description | Size | Format | |
|---|---|---|---|---|
| b25075652.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 2.35 MB | Adobe PDF | View/Open |
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