Biochemical characterization of a novel extended-spectrum beta-lactamase from Pseudomonas aeruginosa 802.
Pseudomonas aeruginosa 802 was isolated at Rabta hospital in Tunis and was resistant to extended-spectrum cephalosporins and aztreonam. It produced a pI 7.6 extended-spectrum beta-lactamase (ESBL). The ESBL, named LBT 802, was purified to homogeneity by filtration on Sephadex G-75 followed by CM-Sepharose chromatography and high-performance liquid chromatography (HPLC) on a TSK-gel SP-5PW column. The LBT 802 enzyme had a molecular mass of 30 kDa. It showed a broad-substrate profile by hydrolyzing benzylpenicillin, ampicillin, cephalothin, cephaloridine, cefotaxime, ceftriaxone, and cefpirome but not ceftazidime, cefoxitin, imipenem, or aztreonam. The highest hydrolytic efficiency (Vmax/Km) was obtained for ampicillin, cephalothin, cephaloridine, and benzylpenicillin. Among extended-spectrum cephalosporins the best substrate was ceftriaxone followed by cefotaxime and cefpirome. LBT 802 activity was inhibited by clavulanic acid, sulbactam, imipenem, cefoxitin, and aztreonam. It showed its lowest Ki values for clavulanic acid, imipenem and sulbactam.
Rejiba
Samia
S
Laboratoire de Biochimie et de Technobiologie, Faculté des Sciences de Tunis, Tunisia.
Limam
Ferid
F
Belhadj
Cherifa
C
Belhadj
Omrane
O
Ben-Mahrez
Kamel
K
D000900:Anti-Bacterial Agents / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006868:Hydrolysis; D007700:Kinetics; D008970:Molecular Weight; D011550:Pseudomonas aeruginosa / Q000201:enzymology*; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases / Q000302:isolation & purification / Q000378:metabolism*; D047090:beta-Lactams
D000900:Anti-Bacterial Agents; D004791:Enzyme Inhibitors; D065093:beta-Lactamase Inhibitors; D047090:beta-Lactams; D001618:beta-Lactamases