A molecular study on bacterial resistance to arsenic-toxicity in surface and underground waters of Latium (Italy)

As-resistant bacterial species respond to toxic As(V) and As(III) species (which enter the microbial cells through membrane-associated phosphate transporters and aquaglyceroporins, respectively). The HGT events of ars regions (the ars operon generally includes the genes encoding ArsC, a cytoplasmic As(V) reductase, and ArsB, a membrane associated As(III) efflux pump for the extrusion of As(III) from the cytoplasm; see Section 1) appear to be a source of resistance to arsenic-toxicity even between distantly related bacteria.