Open AccessSynergistic in vitro activity between aztreonam and amoxicillin–clavulanate against Enterobacteriaceae-producing class B and/or class D carbapenemases with or without extended-spectrum β-lactamases
Author(s) -
Pauline Ract,
Fabrice Compain,
Frédéric Robin,
Dominique Decré,
Salah Gallah,
Isabelle Podglajen
Publication year - 2019
Publication title -
journal of medical microbiology/journal of medical microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 117
eISSN - 1473-5644
pISSN - 0022-2615
DOI - 10.1099/jmm.0.001052
Subject(s) - aztreonam , enterobacteriaceae , microbiology and biotechnology , minimum inhibitory concentration , biology , clavulanic acid , amoxicillin , in vitro , escherichia coli , antibiotics , antibiotic resistance , gene , imipenem , genetics
. Carbapenemase-producing Enterobacteriaceae have become a major public health concern over the last decade and treatment options are limited. Aims. We evaluated the synergistic activity of the combination of aztreonam (ATM) and clavulanate for 41 β -lactam-resistant clinical isolates harbouring class B or/and class D carbapenemases combined or not with extended-spectrum β -lactamases (ESBLs). Methodology. The MICs of ATM, with and without amoxicillin-clavulanate (AMC), were determined. Time-kill assays were performed for three representative strains. Results. The ATM-AMC combination had a synergistic effect on 34/41 (83 %) isolates. The MIC of ATM, in the presence of clavulanate, was ≤1 mg l -1 for 15/41 (37 %) isolates and ≤4 mg l -1 for 29/41 (71 %) isolates. Synergistic activity was observed for 34/37 (92 %) isolates producing ESBLs and carbapenemases, compared to 0/4 (0 %) for ESBL-negative strains. Complete or partial bactericidal activity was obtained when the MIC of the combination was 0.5 mg l -1 and 1.5 mg l -1 or 8 mg l -1 , respectively. Conclusion. The combination of ATM and AMC could be an attractive unconventional treatment for infections due to carbapenemase- and ESBL-producing Enterobacteriaceae.