COMPARATIVE-ASSESSMENT OF THE SOS CHROMOTEST KIT AND THE MUTATOX TESTWITH THE SALMONELLA PLATE INCORPORATION (AMES TEST) AND FLUCTUATION TESTS FOR SCREENING GENOTOXIC AGENTS

Genuine needs for rapid, simple, and cost-efficient biotesting procedu res to screen an ever-increasing number of chemicals and environmental samples are making the search for such assays a constant endeavor. Wi th respect to genotoxicity screening, we compared, in this study, the performance of two novel assays (Vibrio fischeri M169 Mutatox(TM) assa y and the Escherichia coli PQ37 SOS Chromotest kit assay) with two wel l-established Ames testing procedures (plate incorporation and fluctua tion assays). Testing material included 14 chemicals (10 potentially d irectly acting and 4 indirectly acting compounds) reflecting different chemical classes (2 inorganics, 2 pesticides, 2 halogenated hydrocarb ons, 2 alkylating agents, 2 aromatic amines, 1 chlorophenol, and 3 pol ycyclic aromatic hydrocarbons). Comparative assessment criteria includ ed (1) interprocedural agreement in detecting presence or absence of g enotoxicity, (2) accuracy in being able to recognize animal (non)carci nogens, and (3) sensitivity (detection of lowest actively genotoxic co ncentration). In terms of qualitative responses, both the SOS Chromote st (86% agreement) and Mutatox assays (93% agreement) were good predic tors of the Ames testing mutagenicity. For their capability to correct ly discriminate between (non)carcinogens, accuracy was 82% (9 of 11 ch emicals) for Mutatox, 73% (8 of 11 chemicals) for Ames testing, and 64 % (7 of 11 chemicals) for the SOS Chromotest. In general, the Salmonel la-based assays proved more sensitive (6 times out of 9 chemicals) tha n the Mutatox (3 times out of 9 chemicals) and the SOS Chromotest (nev er more sensitive). Overall, this study demonstrates reliable performa nces by both the SOS Chromotest and Mutatox for chemical genotoxicity screening when results are referenced to the well-validated Ames assay . Although additional comparative data with other chemicals will be re quired, it appears likely that these more practical and cost-efficient procedures can be presently useful to screen genotoxic activity of va rious xenobiotics and environmental samples. (C) 1994 by John Wiley & Sons, Inc.