Antibacterial activity of eravacycline against Klebsiella pneumoniae isolates: an in vitro study

ABSTRACT Eravacycline, a novel tetracycline antibiotic, may be an effective treatment option for Klebsiella pneumoniae infections. We thus conducted an in vitro susceptibility analysis for eravacycline in 211 K. pneumoniae isolates. Eravacycline achieved an overall susceptibility rate of 86% against K. pneumoniae , and the sensitivity rates to carbapenem-susceptible Klebsiella pneumoniae and carbapenem-resistant Klebsiella pneumoniae (CRKP) strains were 100% and 84%, respectively. The combined drug sensitivity test in vitro for eravacycline and polymyxin B demonstrated a synergistic effect in 20% of eravacycline-resistant CRKP strains. IMPORTANCE Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a global priority pathogen due to its limited therapeutic options and high morbidity, which urgently needs new antibiotics that are not affected by common resistance mechanisms. As the next generation of fluorocycline antibiotics, eravacycline can circumvent the tetracycline-specific resistance pathways by its structural modifications, which may be a candidate antibiotic for CRKP infections. The present study evaluated the in vitro activity of eravacycline against CRKP strains, including carbapenemase producers, and explored synergistic interactions with existing antibiotics. By determining the efficacy spectrum and combinatorial potential for eravacycline, this study will directly guide clinical strategies to combat infections caused by CRKP and optimize treatment regimens for high-risk populations.