Infections resulting from Mycobacterium abscessus are increasing in prevalence worldwide, with the greatest risk posed to patients with underlying respiratory conditions. Treatment for infections is difficult due to wide ranging intrinsic antimicrobial resistance, which is compounded by the existence of a range of subspecies within the M. abscessus complex, each with varying additional antimicrobial resistance profiles. Previously, the use of β-lactam/β-lactamase inhibitors within a combination therapy has been proposed as an effective treatment option for pulmonary M. abscessus infections. Here, we assess the in vitro efficacy of two non-β-lactam based inhibitors, relebactam and avibactam, as agents against M. abscessus with their respective partner drugs imipenem and ceftazidime, as well as in triplicate combinations with additional β-lactam antibiotics against the M. abscessus complex. We have shown that the commercially available ratio of imipenem to relebactam is the appropriate ratio for bactericidal activity against M. abscessus, whereas the ratio between ceftazidime and avibactam is redundant, due to inactivity of ceftazidime to inhibit the bacteria. We have identified that the use of imipenem and meropenem alongside either relebactam or avibactam yield low minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) for each M. abscessus subspecies, which are within the therapeutically achievable concentration ranges within the epithelial lining fluid of the lungs. We propose the implementation of imipenem with relebactam in place of stand-alone imipenem into the current treatment regime, alongside meropenem, as a future front-line treatment option for M. abscessus complex infections.
|Journal||The Cell Surface|
|Early online date||9 Oct 2021|
|Publication status||Published - Dec 2021|
Bibliographical note© 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license
Funding: J.A.G.C. is grateful to the Academy of Medical Sciences, Global Challenges Research Fund, Birmingham Women’s and Children’s Hospital Charity Research Foundation, Give A Child Health Fund and the family and friends of Michelle Bamber, for their continued support of the Mycobacterial Research Group at Aston University. This research was funded by the Academy of Medical Sciences/the British Heart Foundation/the Government Department of Business, Energy and Industrial Strategy/Global Challenges Research Fund/the Wellcome Trust Springboard Award [SBF003\1088].