Pigment mutation allows competition experiments to assess fitness in Micrococcus luteus

Dormancy is a growth state some bacteria use to survive antibiotic treatment and cause latent infections. Existing antibiotic treatment could be more effective if one could prevent bacteria from entering a dormant state, however potential target genes that regulate dormancy are unknown. From the yellow wild-type Micrococcus luteus (ML), we have developed a colorless mutant (delta-crtE::kan). This mutant can be used to perform competition experiments probing phenotypes of genes regulating dormancy. Competition experiments using ML are significant because they allow for a method comparing the growth of wild-type ML to mutants with knockouts in suspected regulatory genes of dormancy. My project is to demonstrate the pigment mutation in delta-crtE::kan is at a neutral site and does not affect its growth. Results of these experiments show the delta-crtE::kan mutant has similar growth and fitness to wild-type allowing the delta-crtE::kan mutant to act as a substitute for wild-type in future competition experiments. One such experiment is between delta-crtE and a universal stress protein (delta-uspA616::kan) implicated in dormancy. Preliminary data shows the delta-uspA616::kan mutant ML is outcompeted by delta-crtE::kan in nutrient poor media.

Dormancy is a growth state some bacteria use to survive antibiotic treatment and cause latent infections. Existing antibiotic treatment could be more effective if one could prevent bacteria from entering a dormant state, however potential target genes that regulate dormancy are unknown. From the yellow wild-type Micrococcus luteus (ML), we have developed a colorless mutant (delta-crtE