The Impact of the atpB and atpE Genes on Metabolic and Viral Replication Cycles in E. coli

Abstract

Bacteriophage has shown to be a promising treatment for bacterial infections as antibiotic resistance becomes more prevalent. The ability of bacteriophage to effectively infect host cells, however, requires the use of the host cell’s metabolic pathways for energy. Previous research has found that certain genetic alterations within these host cell pathways can disrupt bacterial growth and replication efficiency. In our research, we decided to specifically investigate how bacteriophage replication is affected by deletions of the atpB and atpE genes, which code for proton transport proteins involved in E coli’s ATP biosynthesis pathway. To determine the effects of removing these genes, we first performed streak plates and growth curves with our parent and knockout strains of E. coli to evaluate their impact on bacterial growth. We then ran lysis curves with the parent, ΔatpB, and ΔatpE strains of E. coli using T2 and T4 phage. Finally, we completed a series of plaque assays with the parent and ΔatpB strains and a two time point phage titer experiment to quantify how bacteriophage replication was affected by the knockout gene. We discovered that bacteriophage replication and overall growth of the E. coli was hindered by the ΔatpB and ΔatpE knockout genes. The streak plates and growth curves showed that the knockout strain of E. coli grew significantly slower than the parent strain. The lysis curves revealed that the atpB and atpE knockout strains exhibited far less phage-driven lysis than the parent strain. Additionally, the plaque assays and two time point experiments with the knockout strains showed no plaques forming, while the parent strain had plaque formation. While the atpB gene is nonessential for E. coli growth, it greatly affects the efficiency and ability for the bacteria to grow. This information points to the fact that bacteriophage cannot be used as an effective treatment in bacterial infections that have mutations affecting the atp genes. The results from our experiment also point to the need for more research to be done on effectively knocking out the atp genes as a potential treatment for controlling bacterial infections. We concluded that effective phage replication is dependent on sufficient ATP availability in the host cells. This finding could be used to help improve the efficiency of phage therapy.