A bacterial reporter panel for the detection and classification of antibiotic substances.
Bottom Line: The ever-growing use of pharmaceutical compounds, including antibacterial substances, poses a substantial pollution load on the environment.All of the tested antibiotics were detected by the panel, which displayed different response patterns for each substance.These unique responses were analysed by several algorithms that enabled clustering the compounds according to their functional properties, and allowed the classification of unknown antibiotic substances with a high degree of accuracy and confidence.
Affiliation: Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Jerusalem, Israel.Show MeSH
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Mentions: The utilization of genetically engineered bacteria as bioreporters requires the use of selection markers for maintaining culture purity and for ensuring the stability of functional reporter systems. For obvious reasons, however, selection systems based on antibiotic resistance are not applicable in our case. A few non‐antibiotic selection systems were developed in the past, mainly for use in probiotic microorganisms (Herrero et al., 1990; Maccormick et al., 1995, Fu and Xu, 2000; Bron et al., 2002). We have developed a selectivity marker that is based on the requirement for tryptophan. A tryptophan auxotroph Escherichia coli mutant (ΔtrpE) was used as a host strain, and a plasmid that lacks antibiotic resistance genes but confers the ability to produce tryptophan, pBRlux‐trp, was used as the transformation vector (Fig. 1A and B). The trpED genes, which encode the two subunits of anthranilate synthetase, are co‐ordinately regulated at transcriptional and translational levels (Nichols et al., 1981). When pBRlux‐trp was introduced into the E. coli tryptophan auxotroph strain, it re‐established the ability of the bacterium to self‐synthesize tryptophan and grow on a tryptophan‐free medium, thus providing a selective trait (Fig. 1C).
Affiliation: Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Jerusalem, Israel.