[Comparative antibacterial activity of ceftibuten (SH 39 720) against 150 K. pneumoniae strains producing different beta-lactamases].
Comparative antibacterial activity of ceftibuten (SH 39 720) on 150 K. pneumoniae strains producing different beta-lactamases. MICs of ceftibuten, cefotaxime + clavulanic acid (10 mg/l), ceftazidime and azthreonam were determined for 150 clinical isolates of K. pneumoniae: 15 "wild" type producing only the SHV-1 type beta-lactamase, 15 TEM-1 and 120 producing new "extended spectrum" beta-lactamases (48 CTX-1, 9 SHV-2, 4 SHV-3, 35 SHV-4, 24 SHV-5). Against SHV-1 and TEM-1 strains the bacteriostatic activity of ceftibuten was close to that of the other beta-lactams tested. This activity was preserved against strains producing CTX-1, SHV-2, SHV-3 beta-lactamases and MICs were comparable to those of cefotaxime + clavulanic acid. The MICs of ceftibuten against strains producing SHV-4 and SHV-5 beta-lactamases were higher (1 to 8 mg/l) but this level of antibacterial activity was superior to that of the other beta-lactam antibiotics. The bactericidal activity of ceftibuten was evaluated by kill kinetic studies: this activity was preserved against the CTX-A and SHV-2 strains--with concentrations equal to 2 or 4 x CMI a 4 log10 reduction of the bacterial inoculum was obtained at 24 h. A such reduction was not obtained with cefotaxime. This preserved antibacterial activity of ceftibuten against K. pneumoniae producing some new "extended spectrum" beta-lactamases need further studies to state the structure-activity relation-ships of this antibiotic.
Thabaut
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Laboratoire de Biologie, Hôpital d'Instruction des Armées (HIA), Saint-Mande.
Meyran
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D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002439:Cefotaxime / Q000494:pharmacology; D000077722:Ceftibuten; D002511:Cephalosporins / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000201:enzymology; D001618:beta-Lactamases
D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D001618:beta-Lactamases; D000077722:Ceftibuten; D002439:Cefotaxime
Activité antibactérienne comparée du ceftibutène (SH 39 720) sur 150 souches de K. pneumoniae productrices de différentes bêta-lactamases.