Comparison of T4 Bacteriophage Adsorption and Progeny Production during Infection of Maturing Biofilms of Escherichia coli Wild-type and OmpC Mutants

Previous research into T4 bacteriophage infection of E. coli biofilms observed that during the fourth day of biofilm development, a transient substantial increase in T4 phage progeny production occurs. This increase was hypothesized to be due to over-expression of the outer membrane protein C (OmpC). OmpC is used by T4 bacteriophage for binding to the host cell, therefore its over-expression in biofilm cells could lead to increased adsorption by T4 bacteriophage. This study investigated whether the adsorption of T4 bacteriophage to E. coli biofilms of various ages could be correlated to the production of phage progeny from infected biofilms. E. coli C149 and C157 cells, wild-type and OmpC mutant respectively, were grown into biofilms of various ages and subsequently inoculated with T4 bacteriophage to measure T4 adsorption to the biofilms and T4 progeny production. Although T4 adsorption was found to be highest for the four day-old biofilms, no correlation was observed between the amount of T4 adsorbed and the amount of phage progeny produced. Adsorption of T4 bacteriophage to E. coli biofilms was not observed to be OmpC-dependent and was found to decrease with biofilm age. Further, it appears that E. coli C157 biofilm cells are more capable of supporting phage progeny production than E. coli C149 biofilm cells.