Avibactam reverts the ceftazidime MIC90 of European Gram-negative bacterial clinical isolates to the epidemiological cut-off value. (December 2014)

• Record Type: Journal Article
• Authors: Flamm, Robert K.; Stone, Gregory G.; Sader, Helio S.; Jones, Ronald N.; Nichols, Wright W.
• Is Part Of: Journal of chemotherapy. Volume 26:Number 6(2014:Dec.)
• Page Start: 333
• Page End: 338
• Publication Date: 2014-12
• Subjects: Chemotherapy -- Periodicals; Drug Therapy -- Periodicals; 615.58
• DOI: 10.1179/1973947813Y.0000000145
• Languages: English
• ISSNs: 1120-009X

Abstract

<abstract> <title> <x content-type="archive" xml:space="preserve">Abstract</x> </title> <sec> <title>Objectives:</title> <p>Ceftazidime-avibactam consists of the beta-lactam ceftazidime and the novel non-beta-lactam beta-lactamase inhibitor avibactam. The effect of avibactam on the ceftazidime MIC frequency distribution of Gram-negative European clinical isolates was observed and compared to European Committee for Antimicrobial Susceptibility Testing (EUCAST) MIC frequency distributions and epidemiological cut-off values (ECOFFs) listed for ceftazidime.</p> </sec> <sec> <title>Methods:</title> <p>Ceftazidime and ceftazidime-avibactam MICs were determined using Clinical and Laboratory Standards Institute (CLSI) reference broth microdilution methods for <italic>Pseudomonas aeruginosa</italic>, <italic>Escherichia coli</italic>, <italic>Klebsiella</italic> spp., <italic>Serratia</italic> spp., <italic>Enterobacter</italic> spp., and <italic>Proteus mirabilis</italic> isolates collected from medical centres in Europe during 2009.</p> </sec> <sec> <title>Results:</title> <p>The MIC<sub>90</sub> values for ceftazidime and ceftazidime-avibactam against <italic>P. aeruginosa</italic> isolates from a 2009 European surveillance programme were >32 and 8 mg/l, respectively. That is, the presence of avibactam reverted the ceftazidime MIC<sub>90</sub> for <italic>P. aeruginosa</italic> to the ECOFF. Similarly, the MIC<sub>90</sub> values for ceftazidime against <italic>E. coli</italic>, <italic>Klebsiella</italic> spp., <italic>Serratia</italic> spp., and <italic>P. mirabilis</italic> were also reduced to the ECOFF by the presence of avibactam. Avibactam reduced the ceftazidime MIC<sub>90</sub> value against collected <italic>Enterobacter</italic> spp. to 1 mg/l (>32-fold reduction). No ECOFF has been defined for <italic>Enterobacter</italic> spp. however, it is 1 mg/l for <italic>Enterobacter aerogenes</italic> and <italic>Enterobacter cloacae</italic>.</p> </sec> <sec> <title>Conclusions:</title> <p>The presence of avibactam reverted the ceftazidime MIC<sub>90</sub> for Gram-negative bacteria to the ECOFF.</p> </sec> </abstract>