Bacterial genotoxicity bioreporters.
Bottom Line: Out of these, only one, the umu-test, has been fully validated and ISO- and OECD standardized.Here we review the main directions undertaken in the construction and testing of bacterial-based genotoxicity bioassays, including the attempts to incorporate at least a partial metabolic activation capacity into the molecular design.We list the genetic modifications introduced into the tester strains, compare the performance of the different assays, and briefly describe the first attempts to incorporate such bacterial reporters into actual genotoxicity testing devices.
Affiliation: Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.Show MeSH
Related in: MedlinePlus
Mentions: Electrochemical mutagen screening based on the umu‐test was performed on a microbial chip combined with a SECM device (Matsui et al., 2006). The microbial chip was fabricated by embedding 5 nl of collagen‐immobilized genetically engineered S. typhimurium strain (TA1535/pSK1002 in a microcavity on a glass substrate. β‐Galactosidase activity was monitored by electrochemical determination of the concentration of p‐aminophenol (pAP), the hydrolysis product of pAPG. Recently, a novel microelectro‐mechanical system (MEMS)‐based micro‐chip incorporated in a micro‐fluidic system was constructed and characterized by Ben‐Yoav and colleagues (2009) (Fig. 3). The activity of minute volumes (down to 2.5 nl) of a S. typhimurium strain carrying a umuC′::lacZ fusion and an E. coli strain harbouring a sulA′::phoA fusion was measured after exposure to IQ and NA respectively. The presence of genotoxic materials was detected by chrono‐amperometry using the substrates pAPP (for the phoA reporter) and pAPG (for the lacZ reporter), generating a significant signal after 3 min with MDCs of 0.31 and 42 µM for IQ after metabolic activation and NA respectively.
Affiliation: Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.