In Vitro Susceptibility to Imipenem/Relebactam and Comparators in a Multicentre Collection of Mycobacterium abscessus Complex Isolates
Year: 2025
Type: article
Abstract: Background and Objectives: Infections caused by non-tuberculous mycobacteria (NTM), including Mycobacterium abscessus complex (MABc), are increasing globally and are notoriously difficult to treat due to the intrinsic resistance of these bacteria to many common antibiotics. The aims of this study were to demonstrate the in vitro activity of imipenem/relebactam against MABc clinical isolates and to determine any in vitro synergism between imipenem/relebactam and other antimicrobials. Methods: A nationwide collection of 175 MABc clinical respiratory isolates obtained from 24 hospitals in Spain (August 2022–April 2023) was studied. Fifteen different antimicrobial agents were comprised, including imipenem/relebactam. MICs were determined according to CLSI criteria, and the synergism studies were performed with the selected clinical isolates. Results: Of the 175 isolates obtained, 110 were identified as M. abscessus subsp. abscessus (62.9%), 51 as M. abscessus subsp. massiliense (29.1%), and 14 as M. abscessus subsp. bolleti (8%). The antibiotics yielding the highest susceptibility rates were tigecycline, eravacycline, and omadacycline (100%); followed by imipenem/relebactam and clofazimine (97.6%); and finally amikacin (94.6%). Only four isolates were resistant to imipenem/relebactam, three of which were further characterized by WGS, revealing MABc mutations in BlaMab as well as D,D- and L,D-transpeptidades and mspA porin, which may play an important role in reduced susceptibility to imipenem/relebactam, even though none were previously described or associated with resistance to β-lactams. Conclusions: Our data demonstrate that relebactam improved the anti-MABc activity of imipenem, representing a β-lactam for the treatment of MABc infections. Furthermore, imipenem/relebactam demonstrated in vitro synergism with other anti-MABc treatments, thus supporting its use as part of dual regimens.
Source: Antibiotics
Authors: Alejandro Seoane-Estévez, Pablo Aja-Macaya, Andrea Garcia-Pose, Paula López-Roa, Alba Ruedas-López, Verónica Gonzalez-Galán, Jaime Esteban, Jorge Arca-Suárez, Martín Pampín, Alejandro Beceiro, Marina Oviaño, Germán Bou, on behalf of the GEIM-SEIMC Study Group
Institutions: Universidade da Coruña, Complexo Hospitalario Universitario A Coruña, Servicio Gallego de Salud, Instituto de Investigación Biomédica de A Coruña, Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red, Centro de Investigación Biomédica en Red Enfermedades Infecciosas, Research Institute Hospital 12 de Octubre, Hospital Universitario 12 De Octubre, Hospital Universitario Virgen del Rocío, Instituto de Investigación Sanitaria Fundación Jiménez Díaz
Language: English
Subfield: Epidemiology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,499
Awards: Vacunas auxótrofas orales para la erradicación de bacterias intestinales: colonización intestinal por Klebsiella pneumoniae multirresistente como modelo, G3477070971, Inhibidores de carbapenemasas: actividad frente a Enterobacterales productores de carbapenemasas, mecanismos e impacto en la evolución de la resistencia antimicrobiana (PROTECT), DETECCIÓN RÁPIDA DE RESISTENCIAS ANTIBIÓTICAS MEDIANTE ESPECTROMETRÍA DE MASAS MALDI-TOF
OpenAlex ID: W4412071269