Identification of microbial cell-to-cell interacting mechanisms conferring antimicrobial resistance and virulence

• Main Author: Ting, Hui Jun
• Other Authors: Yang Liang
• Format: Final Year Project
• Language: English
• Published: 2016
• Subjects: DRNTU::Science::Biological sciences::Microbiology
• Online Access: http://hdl.handle.net/10356/68437
• Institution: Nanyang Technological University

Infections are rarely caused by a single bacteria species. In the case of P. aeruginosa infections, different bacteria can be found existing in the same site of infection. This project aims to study the gene expression of lasB, rhlA, pmr and cdrA in P. aeruginosa when co-cultured with different bacteria. K. pneumoniae KP-1 and E. coli UTI89 were observed to down regulate the expression of lasB and rhlA, while up regulating cdrA expression. pmr was up regulated by K. pneumoniae KP-1. Elastase and orcinol assays were performed to compare the functional products, elastase and rhamnolipid encoded by lasB and rhlA of P. aeruginosa wild type, PAO1. Elastase activity of KP-1 with PAO1 and UTI189 with PAO1 supernatant correspond with co-culture done with lasB reporter strains, which had shown less elastase activity as compared to PAO1 culture supernatant. Preliminary result of elastase inhibitor assay were similar to elastase assay. Optimization were needed for elastase inhibitor assay and orcinol assay to obtain conclusive results. K. pneumoniae and E. coli appeared to be interesting candidates for further P. aeruginosa interaction studies.