Antibacterial Activity of Eravacycline Against Carbapenem-Resistant Gram-Negative Isolates in China: An in vitro Study

Abstract

Objective

Eravacycline is a novel, fully synthetic fluorocycline antibiotic being developed for the treatment of serious infections, with a broad-spectrum antimicrobial activity, including against carbapenem-resistant gram-negative bacteria (CRGNB). However, the in vitro activity of eravacycline against CRGNB has not been well known in China. In this study, we analysed the antibacterial activity of eravacycline against CRGNB isolates in order to provide a theoretical basis for the clinical treatment.

Methods

A total of 346 isolates of CRGNB were collected from two different tertiary care hospitals in Zhejiang, China. Carbapenem resistance genes of all isolates were detected by polymerase chain reaction. And we analysed the in vitro activity of eravacycline against CRGNB by antimicrobial susceptibility tests. In addition, the time-kill curves were generated to evaluate the antibacterial effect of tigecycline and eravacycline.

Results

Four different types of carbapenem-resistant isolates were collected, including 50 Escherichia coli isolates, 160 Klebsiella pneumoniae isolates, 42 Enterobacter cloacae complex isolates, and 94 Acinetobacter baumannii isolates. The carbapenem resistance genes were identified in 346 isolates, including bla_KPC-2 (48.0%), bla_OXA-23 (27.2%), bla_NDM-1 (23.1%), and bla_NDM-16 (0.3%). The antimicrobial susceptibility testing results showed that the minimum inhibitory concentration (MIC) values of 346 isolates were within the sensitivity range (≤0.0625~16 mg/L) and that the MIC₅₀ or MIC₉₀ of eravacycline was generally approximately 2-fold lower than tigecycline. In addition, the time-kill curves showed that the bactericidal effect of eravacycline was stronger than that of tigecycline against four different types of isolates.

Conclusion

Our research indicated that eravacycline had a good antibacterial effect on CRGNB, which could provide a theoretical basis for the clinical treatment of drug-resistant bacterial infections in the future.

Keywords:

• eravacycline
• tigecycline
• carbapenem-resistant
• gram-negative isolates
• drug sensitivity
• time-kill curves

Ethical Approval

This study was conducted in accordance with the Declaration of Helsinki and was reviewed and approved by the Research Ethics Committee of Zhejiang Provincial People’s Hospital (QT2022307).

Acknowledgments

This study was supported by the National Natural Science Foundation of China (No. 82172306), Public Technology Research Projects of Zhejiang Province, China (LGD21H190001), and the Medical and Health Research Project of Zhejiang Province, China (2022KY531).

Disclosure

The authors declare that they have no conflicts of interest in this work.