Phage Resistance in Mucoid Mutants of Escherichia coli
Mentor 1
Alita Burmeister
Start Date
28-4-2023 12:00 AM
Description
Phages are viruses that infect bacteria and might be useful as future alternatives to antibiotics. However, bacteria frequently evolve mutations that result in phage resistance. We are studying the mucoidy phenotype, which is generally thought to result in resistance to phage through production of exopolysaccharide that coats the cell. In this study, we investigated the frequency of mucoid mutations and whether mucoid mutants are resistant to phage U136B. To do this, we selected for phage U136B resistance in E. coli through plating our wild type bacteria, BW25113, with phage U136B. We performed a visual screen for mucoid colonies and isolated them through streak plating. To test for phage resistance, we used cross-streak experiments on both overnight cultures and replicate bacterial colonies. We found that mucoid mutants appeared readily under phage U136B selection, and we isolated 28 potential mutants. We confirmed that 27 out of the 28 isolates were consistently resistant to phage U136B. In ongoing work, we are testing if the mucoid mutants have a growth deficiency due to the costly production of excess exopolysaccharide. These results indicate that the evolution of the mucoidy phenotype could lead to negative but infrequent impacts on phage therapy. However, our ongoing research suggests that mucoidy could slow down the spread of bacteria, which could be beneficial in treating pathogenic infections with phage U136B.
Phage Resistance in Mucoid Mutants of Escherichia coli
Phages are viruses that infect bacteria and might be useful as future alternatives to antibiotics. However, bacteria frequently evolve mutations that result in phage resistance. We are studying the mucoidy phenotype, which is generally thought to result in resistance to phage through production of exopolysaccharide that coats the cell. In this study, we investigated the frequency of mucoid mutations and whether mucoid mutants are resistant to phage U136B. To do this, we selected for phage U136B resistance in E. coli through plating our wild type bacteria, BW25113, with phage U136B. We performed a visual screen for mucoid colonies and isolated them through streak plating. To test for phage resistance, we used cross-streak experiments on both overnight cultures and replicate bacterial colonies. We found that mucoid mutants appeared readily under phage U136B selection, and we isolated 28 potential mutants. We confirmed that 27 out of the 28 isolates were consistently resistant to phage U136B. In ongoing work, we are testing if the mucoid mutants have a growth deficiency due to the costly production of excess exopolysaccharide. These results indicate that the evolution of the mucoidy phenotype could lead to negative but infrequent impacts on phage therapy. However, our ongoing research suggests that mucoidy could slow down the spread of bacteria, which could be beneficial in treating pathogenic infections with phage U136B.
