Infection by Bacteriophage T5 and Its Intracellular Growth—a Study by Complement Fixation

Abstract

Infection of a susceptible bacterium by a virulent phage particle is followed, after a latent period, by cell lysis and liberation of newly formed phage particles. The infecting particle loses its infectivity shortly after adsorption to the host, a fact attributed to disociation of the particle into a-cell penetrating fraction, consting chiefly of nucleic acid, and an externally persisting fraction, consisting chiefly of protein and containing at least some of the principal phage antigens (Hershey and Chase, 1952). The study of the intracellular development of virus antigens, initiated with influenza v

The Role of Calcium in the Penetration of Bacteriophage T5 Into Its Host

“…Preliminary experiments confirmed several of the results of Adams (1949), Kay (1952), and Lanni (1954). The following points were established:…”

“…(5) Plating of T5 infected bacteria by the agar layer method directly from chilled samples often causes an important loss of infective centers. This was probably responsible for the loss of infected bacteria that complicated some of the experiments by Lanni (1954). We found that this loss can be avoided if the samples are warmed for several minutes at 37 C before being plated.…”

“…(1) The proportion of plaque forming bacteria was more reduced by blending than the proportion of removable phosphorus. This discrepancy (see also Lanni, 1954) indicates that injection of phage desoxyribonucleic acid, as measured by failure of phage phosphorus to be removed by blending, is not identical with acquisition of resistance to blending, as measured by the plaque forming ability of the bacteria.…”

“…After various intervals, they were diluted in chilled medium without added cations, and 25 ml samples were stirred for 2.5 minutes in a Waring blendor. This treatment removes over 95 per cent of the adsorbed phage antigens from the surface of the bacteria (Lanni, 1954). Blended and control samples were diluted in medium with added Ca and Mg and plated at intervals.…”

A Lytic Providencia rettgeri Virus of Potential Therapeutic Value Is a Deep-Branching Member of the T5virus Genus

“…The host range analysis indicates that PR1 successfully infects most P. rettgeri strains used in this study, with a high efficiency of plating (EOP), while not being able to lyse certain other closely related bacteria of the tribe Proteeae and the Enterobacteriaceae family, such as P. stuartii, P. alcalifaciens, Citrobacter freundii, Morganella morganii, P. mirabilis, or Proteus vulgaris (Table 1). Compared to other characterized phages of T5virus genus (T5 and AKFV33), PR1 presents a short latent period of 25 min and burst size of 32 (23,26).PR1 genomic features. The PR1 virion contains a linear 118,537-bp doublestranded DNA (dsDNA) molecule ( Fig.…”