%0 Journal Article %A Thompson, J.K. %A Hart, M.G.R. %T Novel Patterns of Ultraviolet Mutagenesis and Weigle Reactivation in Staphylococcus aureus and Phage 𝜙11 %D 1981 %J Microbiology, %V 124 %N 1 %P 147-157 %@ 1465-2080 %R https://doi.org/10.1099/00221287-124-1-147 %I Microbiology Society, %X Summary: The effects of u.v. irradiation on the survival of Staphylococcus aureus and its phage 𝜙11 were studied. The recA and uvr mutations affected their survival in a similar way to synonymous mutations in Escherichia coli. Weigle reactivation (W-reactivation) of 𝜙11 occurred in wild-type S. aureus and in a uvr mutant but to a lesser extent than has been found for phage λ in E. coli. Reactivation was recA-dependent and was accompanied by u.v.-induced mutagenesis in a temperature-sensitive mutant of 𝜙11. Bacterial mutation to streptomycin resistance was induced by u.v. and was also recA-dependent. In S. aureus, as in E. coli, u.v. was a more effective mutagen in the uvr genetic background. However, a dose-squared response for u.v.-induced mutation of wild-type and uvr strains of S. aureus to streptomycin resistance, and of a trp auxotroph to tryptophan independence, was found only with u.v. doses below 1 J m−2. We suggest that, in relation to the Uvr mechanism of DNA repair, u.v. mutagenesis in S. aureus involves both repairable and non-repairable lesions. As in E. coli, the uvr genetic background reduced the u.v. dose required for maximal W-reactivation of u.v.-irradiated phage. However, there was no enhancement of W-reactivation by post-irradiation broth incubation of S. aureus. Our results are compatible with a non-inducible mechanism for this phenomenon. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-124-1-147