title: The use of rec-bacteria for testing of carcinogenic substances.
abstract: A series of rec-Escherichia coli strains were tested for their sensitivity to four known carcinogenic compounds by examination of a zone of inhibited bacterial growth around a central well containing the test chemical. The mutants recA-, recB-, recC-, and recA- recB- recC- were all more sensitive to the mutagens than the parental strain AB1157. The recB- recC- strain was examined with a larger series of compounds and was found to respond to many of the substances in a similar way as the Salmonella typhimurium strains of Ames but with some notable exceptions. Nitrosamines, with rat liver microsomal activation, could be detected at lower levels and a group of aromatic amino compounds failed to react with these rec-E. coli. An unusual feature of these rec-mutants is their sensitivity to mixtures of nitrosamines and 2-acetyl amino-fluorene in the absence of microsomal activation.
mesh_terms: D015073:2-Acetylaminofluorene / Q000633:toxicity; D000818:Animals; D002273:Carcinogens / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D004357:Drug Synergism; D004926:Escherichia coli / Q000187:drug effects* / Q000254:growth & development; D008862:Microsomes, Liver / Q000378:metabolism; D009153:Mutagens / Q000633:toxicity*; D009602:Nitrosamines / Q000633:toxicity; D051381:Rats; D011995:Recombination, Genetic
chemical_list: D002273:Carcinogens; D009153:Mutagens; D009602:Nitrosamines; D015073:2-Acetylaminofluorene