Dataset Information

Inhibition of the ?-Lactamase Bla_Mab by Avibactam Improves the In Vitro and In Vivo Efficacy of Imipenem against Mycobacterium abscessus.

ABSTRACT: Mycobacterium abscessus pulmonary infections are treated with a macrolide (clarithromycin or azithromycin), an aminoglycoside (amikacin), and a ?-lactam (cefoxitin or imipenem). The triple combination is used without any ?-lactamase inhibitor, even though Mabscessus produces the broad-spectrum ?-lactamase Bla_Mab We determine whether inhibition of Bla_Mab by avibactam improves the activity of imipenem against M. abscessus The bactericidal activity of drug combinations was assayed in broth and in human macrophages. The in vivo efficacy of the drugs was tested by monitoring the survival of infected zebrafish embryos. The level of Bla_Mab production in broth and in macrophages was compared by quantitative reverse transcription-PCR and Western blotting. The triple combination of imipenem (8 or 32 ?g/ml), amikacin (32 ?g/ml), and avibactam (4 ?g/ml) was bactericidal in broth (<0.1% survival), with 3.2- and 4.3-log₁₀ reductions in the number of CFU being achieved at 72 h when imipenem was used at 8 and 32 ?g/ml, respectively. The triple combination achieved significant intracellular killing, with the bacterial survival rates being 54% and 7% with the low (8 ?g/ml) and high (32 ?g/ml) dosages of imipenem, respectively. In vivo inhibition of Bla_Mab by avibactam improved the survival of zebrafish embryos treated with imipenem. Expression of the gene encoding Bla_Mab was induced (20-fold) in the infected macrophages. Inhibition of Bla_Mab by avibactam improved the efficacy of imipenem against M. abscessusin vitro, in macrophages, and in zebrafish embryos, indicating that this ?-lactamase inhibitor should be clinically evaluated. The in vitro evaluation of imipenem may underestimate the impact of Bla_Mab, since the production of the ?-lactamase is inducible in macrophages.

SUBMITTER: Lefebvre AL

PROVIDER: S-EPMC5365697 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Inhibition of the β-Lactamase BlaMab by Avibactam Improves the In Vitro and In Vivo Efficacy of Imipenem against Mycobacterium abscessus.

Lefebvre Anne-Laure AL Le Moigne Vincent V Bernut Audrey A Veckerlé Carole C Compain Fabrice F Herrmann Jean-Louis JL Kremer Laurent L Arthur Michel M Mainardi Jean-Luc JL

Antimicrobial agents and chemotherapy 20170324 4

Mycobacterium abscessus pulmonary infections are treated with a macrolide (clarithromycin or azithromycin), an aminoglycoside (amikacin), and a β-lactam (cefoxitin or imipenem). The triple combination is used without any β-lactamase inhibitor, even though Mabscessus produces the broad-spectrum β-lactamase BlaMab We determine whether inhibition of BlaMab by avibactam improves the activity of imipenem against M. abscessus The bactericidal activity ...[more]

PMID: 28096155

Similar Datasets

Project description:Mycobacterium abscessus causes serious infections that often require over 18 months of antibiotic combination therapy. There is no standard regimen for the treatment of M. abscessus infections, and the multitude of combinations that have been used clinically have had low success rates and high rates of toxicities. With β-lactam antibiotics being safe, double β-lactam and β-lactam/β-lactamase inhibitor combinations are of interest for improving the treatment of M. abscessus infections and minimizing toxicity. However, a mechanistic approach for building these combinations is lacking since little is known about which penicillin-binding protein (PBP) target receptors are inactivated by different β-lactams in M. abscessus We determined the preferred PBP targets of 13 β-lactams and 2 β-lactamase inhibitors in two M. abscessus strains and identified PBP sequences by proteomics. The Bocillin FL binding assay was used to determine the β-lactam concentrations that half-maximally inhibited Bocillin binding (50% inhibitory concentrations [IC50s]). Principal component analysis identified four clusters of PBP occupancy patterns. Carbapenems inactivated all PBPs at low concentrations (0.016 to 0.5 mg/liter) (cluster 1). Cephalosporins (cluster 2) inactivated PonA2, PonA1, and PbpA at low (0.031 to 1 mg/liter) (ceftriaxone and cefotaxime) or intermediate (0.35 to 16 mg/liter) (ceftazidime and cefoxitin) concentrations. Sulbactam, aztreonam, carumonam, mecillinam, and avibactam (cluster 3) inactivated the same PBPs as cephalosporins but required higher concentrations. Other penicillins (cluster 4) specifically targeted PbpA at 2 to 16 mg/liter. Carbapenems, ceftriaxone, and cefotaxime were the most promising β-lactams since they inactivated most or all PBPs at clinically relevant concentrations. These first PBP occupancy patterns in M. abscessus provide a mechanistic foundation for selecting and optimizing safe and effective combination therapies with β-lactams.

Dataset Information

Inhibition of the ?-Lactamase Bla_Mab by Avibactam Improves the In Vitro and In Vivo Efficacy of Imipenem against Mycobacterium abscessus.

Publications

Inhibition of the β-Lactamase Bla<sub>Mab</sub> by Avibactam Improves the <i>In Vitro</i> and <i>In Vivo</i> Efficacy of Imipenem against Mycobacterium abscessus.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Dataset Information

Inhibition of the ?-Lactamase BlaMab by Avibactam Improves the In Vitro and In Vivo Efficacy of Imipenem against Mycobacterium abscessus.

Publications

Inhibition of the β-Lactamase Bla<sub>Mab</sub> by Avibactam Improves the <i>In Vitro</i> and <i>In Vivo</i> Efficacy of Imipenem against Mycobacterium abscessus.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Inhibition of the ?-Lactamase Bla_Mab by Avibactam Improves the In Vitro and In Vivo Efficacy of Imipenem against Mycobacterium abscessus.