The Action of Bacteriophage Ω8 on Two Strains of Escherichia coli 08

Abstract

Bacteriophage Ω8 is propagated in Escherichia coli E56b (08: K27-:H-), a non-capsulated strain. Another non-capsulated strain, E. coli 2398 (08:K?-:H-), is killed by bacteriophage Ω8 without phage propagation. This strain was formerly believed to be E. coli 093:K?-:H-, cross-reacting with strain E56b. We have established chemical and serological identity of the 08-specific lipopolysaccharides of the two strains. The 08-specific lipopolysaccharides of both strains inhibited the infection of Escherichia coli E56b with bacteriophage Ω8 equally well. The adsorption rate constants of Ω8 were identical for the two strains of E. coli 08. Evidence was obtained with 32P-labelled bacteriophage Ω8 for penetration of viral DNA into both bacterial strains. In host strain E56b, phage particle synthesis occurred normally. In strain 2398 the viral DNA was not degraded but its expression was blocked. The killing effect of Ω8 on E. coli strain 2398 is supposed to be due to damage of the cytoplasmic membrane, which could not be reversed under the influence of viral information. This was indicated by a blockage of cellular respiration, β-galactoside transport and RNA as well as protein synthesis.