title: Effect of preirradiation ribonucleic acid synthesis inhibition on resistance to ultraviolet light with resistant and sensitive strains of Escherichia coli B-r.
abstract: The ultraviolet resistance of a streptolydigin-susceptible strain of Escherichia coli B/r hcr(-) increased during preirradiation treatment with streptolydigin (an inhibitor of deoxyribonucleic acid-dependent ribonucleic acid polymerase) for 20 min and then remained constant. During preirradiation treatment with chloramphenicol (an inhibitor of protein synthesis), resistance to ultraviolet light increased for 1 to 2 h, and reached a maximal level significantly above that attained in streptolydigin-containing medium. These results suggest that there are two mechanisms that function in Hcr(-) cells during chloramphenicol treatment which contribute to the concomitant ultraviolet resistance enhancement. One is ribonucleic acid dependent and is inhibited by streptolydigin. This ribonucleic acid-dependent mechanism appears to be absent in wild-type and RecA E. coli B/r strains.
mesh_terms: D000362:Agar; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001089:Arabinose / Q000378:metabolism; D001426:Bacterial Proteins / Q000096:biosynthesis; D002250:Carbon Radioisotopes; D002701:Chloramphenicol / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects*; D005947:Glucose / Q000378:metabolism; D009154:Mutation; D012329:RNA, Bacterial / Q000096:biosynthesis; D011830:Radiation Effects; D013941:Thymine / Q000378:metabolism; D013997:Time Factors; D014364:Tryptophan / Q000378:metabolism; D014466:Ultraviolet Rays; D014529:Uridine / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002250:Carbon Radioisotopes; D012329:RNA, Bacterial; D002701:Chloramphenicol; D014364:Tryptophan; D000362:Agar; D001089:Arabinose; D005947:Glucose; D013941:Thymine; D014529:Uridine