THE AEROMONAS METALLO-BETA-LACTAMASES - GENETICS, ENZYMOLOGY, AND CONTRIBUTION TO DRUG-RESISTANCE

Aeromonads are environmental microorganisms that can be responsible fo r both human and animal infections, Individual Aeromonas strains can p roduce up to three different, inducible, chromosomally encoded beta-la ctamases, including a group 1 molecular class C cephalosporinase, a gr oup 2d molecular class D penicillinase, and a group 3 molecular class B metallo-beta-lactamase, which contribute to beta-lactam resistance i n members of this genus. Among these enzymes, the metallo-beta-lactama ses are clinically relevant because of their ability to hydrolyze carb apenem antibiotics, and also represent a relevant investigational mode l for studying molecular class B beta-lactamases because of their uniq ue enzymological behavior. An overview on the distribution, genetics, and enzymology of these enzymes is reported, and the contribution of t hese enzymes to microbial drug resistance is also discussed.