In vitro activity of Eravacycline against carbapenem-resistant gram-negative bacilli and associated risk factors for non-susceptible infections from a tertiary hospital in fujian, China from 2021 to 2024.

Background: This study evaluated Eravacycline (ERV)'s effectiveness against carbapenem-resistant gram-negative bacteria (CRGNB) and identified risk factors for ERV non-susceptible Klebsiella pneumoniae (ENSKP) infections to support clinical treatment and early detection.

Methods: Between 2021 and 2024, 235 Carbapenem-Resistant Acinetobacter baumannii(CRAB) strains, 48 Carbapenem-Resistant Escherichia coli (CRECO) strains, and 158 Klebsiella pneumoniae (KP) strains were collected. Resistance genes were identified using PCR, and the minimum inhibitory concentration of tigecycline and ERV was determined using the broth microdilution method. Susceptibility was assessed according to U.S. Food and Drug Administration (FDA) and EUCAST breakpoints, and logistic regression identified ENSKP infection risk factors.

Results: For CRAB, ERV's MIC50 and MIC90 were 0.5 µg/ml and 1 µg/ml, while tigecycline's were 2 µg/ml and 4 µg/ml. For Carbapenem-Resistant Klebsiella pneumoniae (CRKP), ERV's MIC50 and MIC90 were 0.5 µg/ml and 2 µg/ml, and tigecycline's were 2 µg/ml and 4 µg/ml. For CRECO, both ERV and tigecycline had MIC50 and MIC90 of 0.25 µg/ml and 0.5 µg/ml. The study found 25 KP strains non-susceptible to ERV, with no prior ERV treatment. The ENSKP group had higher ECOG scores, more invasive procedures, more antibacterial drug use, and longer hospital stays compared to the ERV susceptible KP.

Conclusion: Our study demonstrated that ERV effectively combats CRGNB, providing a potential basis for future treatment of drug-resistant infections. ENSKP infection can occur without ERV use. Effective surveillance and antibiotic stewardship are essential for managing ENSKP in high-risk patients.