Characterization of a novel phage BUCT800 against Acinetobacter baumannii and its biofilm removal efficiency.

Acinetobacter baumannii (A. baumannii) poses a significant global public health threat. As natural antimicrobial agents, phages hold enormous potential for controlling the spread of A. baumannii by targeting environmental pathogens. In this study, we report the isolation and characterization of a novel phage, BUCT800, from wastewater, which specifically lysed ST2-type A. baumannii and forms transparent plaques surrounded by a halo. We analyzed its physiological properties, genomic features, and biofilm removal efficacy. The phage exhibited an optimal MOI of 0.01 and a latent period of about 15 min, and favorable thermal and pH stability. The genome of phage BUCT800 is 42,018 bp in length, with a G + C content of 39%. BLAST analysis showed that it shares the highest similarity with Acinetobacter phage vB_AbaP_APK26, with a query coverage of 89% and a percent identity of 94.72%. Genomic analysis revealed that BUCT800 belonged to the class Caudoviricetes, family Autoscriptoviridae, and did not harbor any known antibiotic resistance or virulence genes. Phage BUCT800 exhibited varying biofilm removal efficiencies against different bacterial strains. Phage BUCT800 at a titer of 1 × 108 PFU/mL removed 72.4% of the T2347 biofilm. Collectively, these findings underscored the substantial potential of phage BUCT800 as an environmental disinfectant.