Interaction between Candida albicans and Pseudomonas aeruginosa

Loading...
Thumbnail Image
Files
Thesis.pdf(5.71 MB)
Full Text E-thesis
Date
2016
Authors
Konstantinidou, Nina
Journal Title
Journal ISSN
Volume Title
Publisher
University College Cork
Published Version
Research Projects
Organizational Units
Journal Issue
Abstract
Fungal pathogen Candida albicans causes serious nosocomial infections in patients, in part, due to formation of drug-resistant biofilms. Protein kinases (PK) and transcription factors (TF) mediate signal transduction and transcription of proteins involved in biofilm development. To discover biofilm-related PKs, a collection of 63 C. albicans PK mutants was screened twice independently with microtiter plate-based biofilm assay (XTT). Thirty-eight (60%) mutants showed different degrees of biofilm impairment with the poor biofilm formers additionally possessing filamentation defects. Most of these genes were already known to encode proteins associated with Candida morphology and biofilms but VPS15, PKH3, PGA43, IME2 and CEX1, were firstly associated with both processes in this study. Previous studies of Holcombe et al. (2010) had shown that bacterial pathogen, Pseudomonas aeruginosa can impair C. albicans filamentation and biofilm development. To investigate their interaction, the good biofilm former PK mutants of C. albicans were assessed for their response to P. aeruginosa supernatants derived from two strains, wildtype PAO1 and homoserine lactone (HSL)-free mutant ΔQS, without finding any nonresponsive mutants. This suggested that none of the PKs in this study was implicated in Candida-Pseudomonas signaling. To screen promoter sequences for overrepresented TFs across C. albicans gene sets significantly up/downregulated in presence of bacterial supernatants from Holcombe et al. (2010) study, TFbsST database was created online. The TFbsST database integrates experimentally verified TFs of Candida to analyse promoter sequences for TF binding sites. In silico studies predicted that Efg1p was overrepresented in C. albicans and C. parapsilosis RBT family genes.
Description
Keywords
Candida albicans , Candida albicans morphology and biofilms , Pseudomonas aeruginosa , TFbsST database , In silico analysis of Candida albicans promoter sequences , Protein kinase , Biofilms , Filamentation , Transcription factor binding site motifs , Promoter regions , Yeast hyphae , Candida albicans morphology and interaction with Pseudomonas aeruginosa
Citation
Konstantinidou, N. 2016. Interaction between Candida albicans and Pseudomonas aeruginosa. PhD Thesis, University College Cork.