title: [Beta-lactamase induction in Pseudomonas aeruginosa by cefpiramide and 3 other antipyocyanic cephalosporins].
abstract: Cefpiramide (SR 95445) (CPM) is a new cephalosporin with activity against Pseudomonas and a good bioavailability following parenteral administration. This drug is a first rather than second choice treatment in Pseudomonas infections. For this reason, investigation into cefpiramide's capacity to induce beta-lactamase production is especially interesting. A heavy inoculum of P. aeruginosa NCTC 8203, a strain that produces and inducible cephalosporinase (pI = 8.7) was incubated for 4 hours with CPM, cefsulodin (CFS), cefoperazone (CPZ) and ceftazidime (CTZ) in various concentrations. After collection and sonic treatment of the bacteria, the beta-lactamase activity was assayed using an acidimetric method and expressed as units of enzyme activity per mg proteins in the cell-free extract. The smallest increase in beta-lactamase production was recorded with CPM. The strongest inductor was CTZ. CFS and CPZ had an intermediate effect.
mesh_terms: D002438:Cefoperazone / Q000494:pharmacology; D002441:Cefsulodin / Q000494:pharmacology; D002442:Ceftazidime / Q000494:pharmacology; D002510:Cephalosporinase / Q000096:biosynthesis; D002511:Cephalosporins / Q000494:pharmacology*; D004355:Drug Stability; D004790:Enzyme Induction / Q000187:drug effects; D011550:Pseudomonas aeruginosa / Q000201:enzymology*; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: D002511:Cephalosporins; D002438:Cefoperazone; D002442:Ceftazidime; D002510:Cephalosporinase; D001618:beta-Lactamases; D002441:Cefsulodin; C036666:cefpiramide
vernacular_title: Etude de l'induction de bêta-lactamase chez Pseudomonas aeruginosa par le cefpiramide et trois autres céphalosporines antipyocyaniques.