TbtABM, a multidrug efflux pump associated with tributyltin resistance in Pseudomonas stutzeri.

Tributyltin (TBT) is a toxic agent used in marine antifouling paints. Among the bacterial flora of a polluted harbor, TBT-resistant strains of Pseudomonas stutzeri have been isolated. In the strain 5MP1 (TBT minimum inhibitory concentration (MIC) > or =1000 mg l(-1)), TBT resistance was found to be associated with the presence of the operon tbtABM, homologous to the resistance-nodulation-cell division (RND) efflux pump family, as demonstrated by cloning in Escherichia coli.

Type II topoisomerase quinolone resistance-determining regions of Aeromonas caviae, A. hydrophila, and A. sobria complexes and mutations associated with quinolone resistance.

Most Aeromonas strains isolated from two European rivers were previously found to be resistant to nalidixic acid. In order to elucidate the mechanism of this resistance, 20 strains of Aeromonas caviae (n = 10), A. hydrophila (n = 5), and A.