Comparative studies on Salmonella johannesburg bacteriophages: morphology, virulence and interactions with the host...

Two long-tailed and two short-tailed bacteriophages are spontaneously released from the Salmonella johannesburg 7.58(R+) strain, and could be propagated on the susceptible strain 5.58(R-). The two long-tailed phages could be distinguished by their tail morphology, and are not adsorbed on a column of sepharose coupled to LPS (R-). The two short-tailed particles (group C of Bradley, group C1 of Ackermann) are converting phages. They are thermostable, are adsorbed on a column of sepharose-LPS, and possess an endo-glycosidase activity leading to the cleavage of the LPS of the sensitive strain. However, one of these short-tailed phages, termed phi 1(40), is a temperate phage producing small and turbid plaques, although the other one, termed phi 1(40)vir, is a virulent phage producing large and clear plaques. A polysaccharidic antigen could be coupled to these phages but the corresponding antiserum was unable to inactivate the modified bacteriophages.