JAC Advance Access originally published online on July 14, 2004
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Journal of Antimicrobial Chemotherapy 2004 54(2):410-417; doi:10.1093/jac/dkh358
JAC vol.54 no.2 © The British Society for Antimicrobial Chemotherapy 2004; all rights reserved.
In vitro activity of AVE1330A, an innovative broad-spectrum non-ß-lactam ß-lactamase inhibitor
Aventis Pharma, 1 Infectious Disease Group and 2 Medicinal Chemistry, 102, Route de Noisy, 93235 Romainville Cedex, France
* Corresponding author. Tel: +33-1-49-91-50-12; Fax: +33-1-49-91-26-42; Email: alain.bonnefoy{at}freesbee.fr
Objectives: Production of ß-lactamases is the main mechanism of ß-lactam resistance in Gram-negative bacteria. Despite the current use of clavulanic acid, sulbactam and tazobactam, the prevalence of class A and class C enzymes is increasing worldwide, demanding new ß-lactamase inhibitors. Here we report the antimicrobial properties of AVE1330A, a representative of a novel class of bridged bicyclico[3.2.1]diazabicyclo-octanones in combination with ceftazidime.
Materials and methods: IC50 and kinetic parameters of the hydrolysis reaction were used to characterize ß-lactamase inhibition by AVE1330A. MICs for >600 strains were determined with the combination ceftazidime/AVE1330A at a fixed ratio of 4:1.
Results: IC50s of AVE1330A for TEM-1 and P99 enzymes were 0.0023 mg/L (8 nM) and 0.023 mg/L (80 nM), compared with 0.027 mg/L (130 nM) and 205.1 mg/L (1 x 106 nM) of clavulanic acid and 0.013 mg/L (40 nM) and 1.6 mg/L (5000 nM) of tazobactam. A highly stable covalent complex led to a low turnover of AVE1330A. MICs of ceftazidime/AVE1330A for Enterobacteriaceae were at least eight-fold lower than those of ceftazidime alone. All of the Escherichia coli, Klebsiella pneumoniae, Citrobacter and Proteus mirabilis strains, including ceftazidime-resistant isolates, were inhibited at 48 mg/L. Only 2 mg/L were required to inhibit other Proteeae, Enterobacter, Salmonella and Serratia.
Conclusion: The combination of ceftazidime with AVE1330A exhibited broad-spectrum activity against Ambler class A- and class C-producing Enterobacteriaceae.
Keywords: AmpC , ESBLs , combinations , ceftazidime