Supernatants of Escherichia coli K-12 Wildtype Strain and ΔOmpC Mutant Strains do not Confer Resistance to T4 Bacteriophage Infection of K-12 WT cells


Harvir Grewal, Zhong (Zack) Dang, Yu Sen (Sam) Zhai, JaeHyung (Duke) Sheen

Volume 24
Fall 2018 / Winter 2019

T4 bacteriophage has been well established in its ability to infect Escherichia coli K-12 strains, particularly strain BW25113, through an OmpC-dependent pathway with outer membrane porin C (OmpC) and lipopolysaccharide (LPS) as receptors. Previous studies have suggested that E. coli may have a protective mechanism against phage infection that involves the production and release of OmpC-containing outer membrane vesicles (OMVs) into the culture supernatant as decoys to neutralize phage particles. In this study, we investigated if there exists a difference in the ability of T4 to infect the wildtype (WT) K-12 strain BW25113 in presence of OmpC-containing BW25113 supernatant compared to K-12 ΔompC mutant strain JW2203-1 supernatant. We hypothesized that incubating BW25113 with WT supernatant would confer an observable level of resistance to T4 infection, whilst incubation of BW25113 with ΔompC mutant supernatant would yield negligible protective effects. To test our hypothesis, we performed several growth curve assays in which BW25113 was grown in either WT or ΔompC mutant supernatant, infected with T4 bacteriophage upon inoculation and grown for up to 8 hours. Contrary to our hypothesis, the experimental results demonstrated that there is no difference in T4-mediated cell lysis between BW25113 incubation with WT versus ΔompC mutant supernatant.