Isolation and characterization of novel bacteriophage, vBAbaASWMUZ8, targeting multidrug-resistant Acinetobacter baumannii strains

Acinetobacter baumannii is a significant opportunistic pathogen causing severe nosocomial infections that poses increasing clinical challenges due to escalating multidrug resistance. Phage therapy has emerged as a promising alternative strategy to combat multidrug-resistant (MDR) infections. In this study, a lytic phage targeting ST208/KL2-type A. baumannii strain Ac28 was isolated and purified from hospital sewage. Whole-genome sequencing and a bioinformatics analysis successfully identified a novel podovirus, designated “vBAbaASWMUZ8”. A host-range analysis demonstrated a lysis rate of 58. 33% against 84 clinically derived A. baumannii isolates of diverse multilocus sequence types, with particularly high efficacy against 88% of ST208 strains. Notably, vBAbaASWMUZ8 lysed 100% of geographically co-localized isolates. It inhibited the growth of MDR A. baumannii strain Ac28 in vitro and improve survival rates in a Galleria mellonella infection model. In this work, we identified a therapeutically promising lytic phage and provided evidence for the phage-based control of MDR A. baumannii infections.