DeMarini D M, Brooks H G
Genetic Toxicology Division, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711.
Environ Mol Mutagen. 1992;19(2):98-111. doi: 10.1002/em.2850190204.
Twenty-eight chlorinated organic compounds were evaluated for their ability to induce DNA damage using the Microscreen prophage-induction assay in Escherichia coli. Comparison of the performance characteristics of the prophage-induction and Salmonella assays to rodent carcinogenicity assays showed that the prophage-induction assay had a somewhat higher specificity than did the Salmonella assay (70% vs. 50%); sensitivity, concordance, and positive and negative predictivity were similar for the two microbial assays. The Microscreen prophage-induction assay failed to detect eight carcinogens, perhaps due to toxicity or other unknown factors; five of these eight carcinogens were detected by the Salmonella assay. However, the prophage-induction assay did detect six carcinogens that were not detected by the Salmonella assay, and five of these were single-species, single-site carcinogens, mostly mouse liver carcinogens. Some of these carcinogens, such as the chloroethanes, produce free radicals, which may be the basis for their carcinogenicity and ability to induce prophage. The prophage-induction (or other SOS) assay may be useful in identifying some genotoxic chlorinated carcinogens that induce DNA damage that does not revert the standard Salmonella tester strains.
使用大肠杆菌中的微筛前噬菌体诱导试验，对28种氯化有机化合物诱导DNA损伤的能力进行了评估。将前噬菌体诱导试验和沙门氏菌试验的性能特征与啮齿动物致癌性试验进行比较，结果表明，前噬菌体诱导试验的特异性略高于沙门氏菌试验（分别为70%和50%）；两种微生物试验的敏感性、一致性以及阳性和阴性预测值相似。微筛前噬菌体诱导试验未能检测出8种致癌物，这可能是由于毒性或其他未知因素所致；沙门氏菌试验检测出了这8种致癌物中的5种。然而，前噬菌体诱导试验确实检测出了6种沙门氏菌试验未检测出的致癌物，其中5种是单物种、单部位致癌物，主要是小鼠肝癌致癌物。这些致癌物中的一些，如氯乙烷，会产生自由基，这可能是它们致癌性和诱导前噬菌体能力的基础。前噬菌体诱导（或其他SOS）试验可能有助于识别一些能诱导DNA损伤但不会使标准沙门氏菌测试菌株回复突变的遗传毒性氯化致癌物。
