Anahit Penesyan

Event Date: 
Tuesday, September 26, 2017 - 19:00 - 19:45
Macquarie University

Life Changing Experiences: Understanding How Microbes Respond and Adapt Using High Throughput -omics Approaches.


Microbes respond, evolve and adapt to changes in the environment. In this talk I will present results of two studies.
One study investigated a long-term adaptation strategy adopted by a Pseudomonas aeruginosa strain PASS4 isolated from the sputum of an adult cystic fibrosis (CF) patient. PASS4 displayed an unusual phenotype, only showing strong respiration on adenosine and inosine in Biolog Phenotype Microarray screening. Further testing indicated that PASS4 could grow on DNA as a sole carbon source with a higher biomass production compared to the model strain of P. aeruginosa PAO1. This suggested that PASS4 has adapted to metabolise eDNA, a substrate present at high concentrations in the CF lung. Further studies of PASS4 strain revealed the possible mechanism behind this specialisation.
The second study looked at how, and how quick, bacteria can adapt by using a common drug-resistant hospital pathogen Acinetobacter baumannii grown in an in vitro biofilm system, with and without the addition of antibiotics. RNA-Seq transcriptomics was used to look at what happens in biofilm cells and showed significant difference in gene expression profiles between planktonic and biofilm cells, while the addition of antibiotics further resulted in specific changes in gene expression. Cells were isolated from biofilm effluents and their genomic DNA sequenced in order to identify genomic changes that might have occurred as a result of growth in biofilms, in the presence / absence of antibiotics.