Comparison of Salmonella typhimurium TA102 with Escherichia coli WP2 tester strains

Abstract

In 1982, Levin et al. published a paper describing a new Salmonella typhimurium strain, TA102, for detecting mutagenic agents that react preferentially with AT base pairs. This strain has an AT base pair at the critical mutation site within the hisG gene, which is located on a multicopy plasmid, pAQ1; the chromosomal copy of the hisG gene has been deleted. It also has an intact excision repair system, thus facilitating the detection of cross-linking agents, and carries the mutator plasmid, pKM101. Although TA102 has been shown to be reverted by certain mutagenic agents that are not detected in the usual battery of strains (TA1535, TA1537, TA1538, TA98 and TA100), there has been a general reluctance within the field to include TA102 as one of the standard screening strains. This may in part result from the difficulties which have been experienced in many laboratories in maintaining the strain, and in obtaining reproducible spontaneous and induced revertant counts. At Glaxo we routinely include certain Escherichia coli strains in our microbial test battery, and were aware that some of the genetic features offered by TA102 were already being covered by these strains. For example, E.coli WP2 (pKM101) has an AT base pair at the critical mutation site within the trpE gene, is excision proficient (and thus will detect cross-linking agents) and carries the pKM101 plasmid to enhance error-prone repair. From the published literature it was apparent that a number of the 'TA102 specific' mutagens could be detected in E.coli e.g. neocarzinostatin, UV and 8-MOP plus UV.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of Glutaraldehyde Exposure on Human Health

“…GA was positive in the DNA repair test by liquid recassay 83) and by umu test without S9 activation 84) . GA was mutagenic in E. coli WP2 tester strains 79) , but yielded negative results in the SOS chromotest with E. coli PQ37 80) . GA did not induce mutation in in vitro chromosomal aberration tests, in sister chromatid exchanges (SCE) tests, or forward gene mutation assays in cultured Chinese hamster ovary cells 76,81) .…”

“…Both positive and negative results have been reported in in vitro mutagenicity studies [76][77][78][79][80][81][82][83][84][85][86] , while almost all in vivo tests have yielded negative results 75,76,87,88) . GA exhibited mild to strong mutagenic effects with and without S9 metabolic activation in S. typhimurium strain TA102 [77][78][79] . In TA100, negative results were reported both with and without S9 81) , while weakly positive results were reported with S9 76) .…”

ToxDelta: A New Program to Assess How Dissimilarity Affects the Effect of Chemical Substances

“…Bruce Ames created the Ames assay in the 1970s [37]. The assay's sensitivity towards many types of mutagens has been improved over the years [38,39]. Specific distinct mutations in the histidine and tryptophan synthetic pathways of Salmonella typhimurium and Escherichia coli have been created respectively, that result in the requirement for an exogenous supply of those amino acids for growth.…”

Different responses in mutagenesis induced by quinolone antibacterial agents in two Escherichia coli WP2uvrA/ pKM101 strains

“…Many studies have indicated that E. coli WP2uvrA/pKM101 is a susceptible strain for detecting numerous mutagens, especially oxidative and cross-linking agents (Wilcox et al, 1990;Watanabe et al, 1996Watanabe et al, , 1998aWatanabe et al, and 1998b. We have previously reported that twelve quinolone antibac--efloxacin, moxifloxacin, norfloxacin, ofloxacin, sita-E. coli WP2uvrA/pKM101 (Hayasaki et al, 2006).…”