A Novel Elizabethkingia anophelis Phages

The rise of multidrug-resistant Elizabethkingia anophelis presents a significant public health challenge. Here, we report the isolation, morphological and biological characterization, and genomic analysis of a novel lytic bacteriophage, XANYB1,targeting E. anophelis. XANYB1 was isolated from hospital wastewater in Xi'an, China, using a clinical strain as the host.Transmission electron microscopy revealed that XANYB1 belongs to the order Caudovirales, featuring icosahedral heads and long, non-contractile tails. Whole-genome sequencing showed very low similarity to known phages, confirming XANYB1as a novel bacteriophage. The optimal multiplicity of infection (MOI) was determined, and one step growth curve analysis indicated a latent period of 30 minutes and a lysis period of approximately 40 minutes. Host range analysis showed that XANYB1 lysed 5 of 14 clinical E. anophelis isolates. In a mouse sepsis model, XANYB1 exhibited effective in vivo antimicrobial activity, highlighting its potential as a therapeutic candidate. These findings support the application of XANYB1 in phage therapy against multidrug-resistant E. anophelis infections.