Eravacycline and omadacycline Rescue multidrug-resistant Elizabethkingia anophelis: Triple-Model evaluation across in Vitro, Galleria mellonella, and murine bacteremia systems.

INTRODUCTION

Elizabethkingia anophelis has emerged as a formidable pathogen causing severe, life-threatening human infections. Treatment remains challenging due to its intrinsic multidrug resistance.

OBJECTIVES AND

METHODS

This study presents the first evaluation of eravacycline and omadacycline efficacy against E. anophelis in vitro and in vivo. Susceptibility testing of 197 clinical isolates employed broth microdilution. Galleria mellonella larval infection and murine bacteremia models assessed therapeutic efficacy.

RESULTS

Minimum inhibitory concentration (MIC) analyses demonstrated potent in vitro activity against clinical isolates, with MICs as low as 0.06 mg/L and 0.125 mg/L, respectively. In the G. mellonella model, both agents significantly delayed larval mortality (P < 0.01) and improved health indices. Murine studies showed substantial reductions in bacterial burden versus saline controls, alongside significant anti-inflammatory and organ-protective effects. Eravacycline achieved complete bacterial eradication in hepatic, splenic, and pulmonary tissues.

CONCLUSION

These findings substantiate the robust antimicrobial efficacy of eravacycline and omadacycline against E. anophelis, offering valuable insights for optimizing clinical management. They provide compelling proof-of-concept that fluorocyclines eradicate multidrug-resistant E. anophelis in vitro and in vivo, strongly supporting clinical trial investigation.