Abstract Summary/Description
Bacteriophage therapy has been around for more than 80 years and aids in healthcare advancements. Due to the specificity of phages, they have evolved to target a certain bacterial strain or species. CRISPR-cas immune system is a defense mechanism against invading nucleic acid, such DNA from invading bacteriophage. It has been proposed that as a system CRISPR-cas is favored when cells have abundant energy. Alternative to CRISPR-cas, bacteria can be selected and lose receptors that bacteriophages use to attach to the cell surface. However, modifications in these receptors can reduce bacteria fitness. To our knowledge no work has looked at the environmental osmolarity as a factor which would impact CRISPR-cas immune system fitness. Environmental osmolarity plays a large role in how nucleic acids are able to get across membranes. This project’s focus is to view how resistance to the phage (DMS3-vir) in PA14 differs in different environmental conditions. We propose, as salt concentration outside the cell become similar to inside, phage DNA will enter the at a slower rate due to the difference in water potential. Giving the CRISPR system more time to evaluate the incoming DNA. On the contrary, at low salt concentrations, the phage DNA should be entering the bacterial at a faster rate due to the same process of moving from low salt concentration on the outside to high salt concentration on the inside.
