Biochemical-genetic characterization of the chromosomally encoded extended-spectrum class A beta-lactamase from Rahnella aquatilis.
From whole-cell DNA of a clinical isolate of the enterobacterial species Rahnella aquatilis, a beta-lactamase gene was cloned that encoded a chromosomally encoded Ambler class A enzyme, RAHN-1. RAHN-1, with a pI of 7.2, shares 76, 73, and 71% amino acid identity with the extended-spectrum beta-lactamase of chromosomal origin from Serratia fonticola and with the plasmid-mediated beta-lactamases CTX-M-2 and CTX-M-1, respectively. The hydrolysis spectrum of the clavulanic acid-inhibited RAHN-1 was expanded to cephalosporins such as cefuroxime, cefotaxime, and ceftriaxone, but not to ceftazidime. Its expression was not inducible.
Bellais
S
S
Service de Bactériologie-Virologie, Hôpital de Bicêtre, Assistance Publique/Hôpitaux de Paris, Faculté de Médecine Paris-Sud, 78 rue de Général Leclerc, 94275 Le Kremlin-Bicêtre Cedex, France.
Poirel
L
L
Fortineau
N
N
Decousser
J W
JW
Nordmann
P
P
D000595:Amino Acid Sequence; D002511:Cephalosporins / Q000378:metabolism; D002876:Chromosomes, Bacterial; D003001:Cloning, Molecular; D006801:Humans; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D020638:Rahnella / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism; D047090:beta-Lactams / Q000494:pharmacology
D002511:Cephalosporins; D047090:beta-Lactams; D001618:beta-Lactamases