Mutants of Staphylococcus aureus with Increased Sensitivity to Ultraviolet Radiation

Abstract

Nitrosoguanidine (NG) mutagenesis of Staphylococcus aureus resulted in the isolation of eight mutants exhibiting 3 to 28 times greater sensitivity to ultraviolet (UV) radiation. These mutants were further characterized by their ability to repair UV-irradiated bacteriophage, to act as recipients in the transduction of antibiotic resistance, and their sensitivity to NG. Based on the available data, six of these mutants are reduced in their ability to perform host-cell reactivation. One of the remaining two mutants may be deficient in post-replication repair.

Isolation of the rec Mutants in Staphylococcus aureus

“…Goering et al (7) isolated eight UV-sensitive mutants but concluded that these mutants were not rec-type mutants. On the contrary, many genetic properties of UV-sensitive mutants isolated in this laboratory were found to be quite similar to those in E. coli rec-strains (5,8), indicating that they are quite sensitive to UV irradiation or mutagenic agents such as NG and MC.…”

Genetics and biology of mutations affecting genetic recombination, sensitivity to alkylating agents, and apurinic endonuclease in Staphylococcus aureus

“…aureus nucleases. Furthermore, the UV sensitivity suggested that S. aureus has two repair pathways for UV-generated DNA damage: the UV excision pathway described by Goering and Pattee (1971) and a unique pathway which is AP endonucleasedependent.…”

“…NQO has been shown to mimic UV irradiation so closely that mutants of E. coli and B. subtilis impaired in UV excision repair (i.e., nucleotide excision) were sensitive to this compound (Kondo et al, 1970;Ikenaga et al 1981;Dai et al, 1983;Friedman and Yasbin, 1983). In S. aureus, the uvs mutations are believed to impair UV excision repair based on their sensitivity to UV irradiation and inability to reactivate UV irradiated bacteriophage (Goering and Pattee, 1971); like their counterparts in E. coli and B. subtilis, these uvs mutations also cause sensitivity to NQO (unpublished results). In contrast, ngr-374-Garrying strains were not sensitive to NQO, which suggests that this mutation was not in one of the uvs genes.…”

“…A number of Rec" strains have been isolated in S. aureus, and in each instance the isolation was based on sensitivity to either UV irradiation (Goering and Pattee, 1971;Inoue et al, 1972;Wyman et al, 1974) or N-methyl-N-nitro-N-nitrosoguanidine (MNNG;Goering, 1979). The first mutation reported to cause a deficiency in recombination in S. aureus was uvs-1 described by Goering and Pattee (1971) in strain 112.…”

“…However, more extensive studies with reoAl and other rec mutations (Goering and Pattee, 1971;Inoue et al, 1972;Goering, 1979) are limited by the inability to genetically transfer these mutations. The rec mutations, such as recAl, are unselectable alleles and efficient genetic transfer of these mutations is possible only when these mutations can be cotransferred with readily selectable markers.…”