Mechanisms that Determine the Differential Stability of Stx+ and Stx− Lysogens
AbstractPhages 933W, BAA2326, 434, and λ are evolutionarily-related temperate lambdoid phages that infect Escherichia coli. Although these are highly-similar phages, BAA2326 and 933W naturally encode Shiga toxin 2 (Stx+), but phage 434 and λ do not (Stx−). Previous reports suggest that the 933W Stx+ prophage forms less stable lysogens in E. coli than does the Stx− prophages λ, P22, and 434. The higher spontaneous induction frequency of the Stx+ prophage may be correlated with both virulence and dispersion of the Stx2-encoding phage. Here, we examined the hypothesis that lysogen instability is a common feature of Stx+ prophages. We found in both the absence and presence of prophage inducers (DNA damaging agents, salts), the Stx+ prophages induce at higher frequencies than do Stx− prophages. The observed instability of Stx+ prophages does not appear to be the result of any differences in phage development properties between Stx+ and Stx− phages. Our results indicate that differential stability of Stx+ and Stx− prophages results from both RecA-dependent and RecA-independent effects on the intracellular concentration of the respective cI repressors. View Full-Text
Share & Cite This Article
Colon, M.P.; Chakraborty, D.; Pevzner, Y.; Koudelka, G.B. Mechanisms that Determine the Differential Stability of Stx+ and Stx− Lysogens. Toxins 2016, 8, 96.
Colon MP, Chakraborty D, Pevzner Y, Koudelka GB. Mechanisms that Determine the Differential Stability of Stx+ and Stx− Lysogens. Toxins. 2016; 8(4):96.Chicago/Turabian Style
Colon, Michael P.; Chakraborty, Dolonchapa; Pevzner, Yonatan; Koudelka, Gerald B. 2016. "Mechanisms that Determine the Differential Stability of Stx+ and Stx− Lysogens." Toxins 8, no. 4: 96.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.