Activity of Imipenem-Relebactam against a Large Collection of Pseudomonas aeruginosa Clinical Isolates and Isogenic β-Lactam-Resistant Mutants

Pablo A Fraile-Ribot ¹, Laura Zamorano ¹, Rocío Orellana ¹, Ester Del Barrio-Tofiño ¹, Irina Sánchez-Diener ¹, Sara Cortes-Lara ¹, Carla López-Causapé ¹, Gabriel Cabot ¹, Germán Bou ³, Luis Martínez-Martínez ⁴, Antonio Oliver ²; GEMARA-SEIMC/REIPI Pseudomonas Study Group

¹Servicio de Microbiología, Hospital Son Espases, Instituto de Investigación Sanitaria Illes Balears (IdISBa), Palma de Mallorca, Spain.

²Servicio de Microbiología, Hospital Son Espases, Instituto de Investigación Sanitaria Illes Balears (IdISBa), Palma de Mallorca, Spain laura.zamorano@ssib.es antonio.oliver@ssib.es.

³Servicio de Microbiología, Hospital Universitario La Coruña, Instituto Investigación Biomédica A Coruña (INIBIC), A Coruna, Spain.

³ Unidad de Gestión Clínica de Microbiología, Hospital Reina Sofía, Departamento de Microbiología, Universidad de Córdoba, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Cordoba, Spain.

Abstract:

Imipenem and imipenem-relebactam MICs were determined for 1,445 Pseudomonas aeruginosa clinical isolates and a large panel of isogenic mutants showing the most relevant mutation-driven β-lactam resistance mechanisms. Imipenem-relebactam showed the highest susceptibility rate (97.3%), followed by colistin and ceftolozane-tazobactam (both 94.6%). Imipenem-relebactam MICs remained ≤2 μg/ml in all 16 isogenic PAO1 mutants and in 8 pairs of extensively drug-resistant clinical strains that had developed resistance to ceftolozane-tazobactam and ceftazidime-avibactam due to mutations in OXA-10 or AmpC.

Antimicrob Agents Chemoter. 2020 Jan 27;64(2):e02165-19. doi: 10.1128/AAC.02165-19.

Link to Antimicrob Agents Chemoter