title: The beta-lactamases of Citrobacter diversus and their hydrolysis kinetics for some structurally-related cephalosporins.
abstract: We measured the kinetics of hydrolysis of various cephalosporins by the chromosomally-encoded beta-lactamases of Citrobacter diversus ULA-27. Cefonicid, cefamandole, cefatrizine and cefoperazone were all hydrolyzed but these antibiotics showed a different feature in their kinetic parameters. Moreover, cefoperazone was a non-competitive inhibitor of this type of enzyme. Cefotetan was stable to hydrolysis and behaved like a progressive inactivator. The ability of these enzymes to inactivate the reported antibiotics contributes largely to the resistance of the studied strain. We conclude that hydrolysis is the main mechanism of resistance of this strain to the new cephalosporins.
authors.affiliation: Dipartimento di Scienze e Tecnologie Biomediche e di Biometria, Facoltà di Medicina, Università di L'Aquila, Italia.
authors.forename: G
authors.initials: G
authors.lastname: Amicosante
authors.forename: B
authors.initials: B
authors.lastname: Segatore
authors.forename: M
authors.initials: M
authors.lastname: Perilli
authors.forename: A
authors.initials: A
authors.lastname: Felici
authors.forename: N
authors.initials: N
authors.lastname: Franceschini
mesh_terms: D002453:Cell Cycle / Q000187:drug effects; D002511:Cephalosporins / Q000494:pharmacology*; D002954:Citrobacter / Q000187:drug effects / Q000201:enzymology*; D008826:Microbial Sensitivity Tests; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: D002511:Cephalosporins; D001618:beta-Lactamases