Characterization and genome annotation of a newly detected bacteriophage infecting multidrug-resistant Acinetobacter baumannii

A novel virulent bacteriophage, φAbp2, infecting multidrug-resistant (MDR) Acinetobacter baumannii was isolated from the wastewater of a sewage management centre at Southwest Hospital, China. Transmission electron microscopy and phylogenetic analysis revealed that φAbp2 belongs to the subfamily Peduovirinae. A one-step growth curve demonstrated that φAbp2 had a latent period of 15 min, a lysis period of 35 min, and a burst size of 222 particles per infected host cell. Moreover, φAbp2 showed a relatively broad host range in local A. baumannii, and it also exhibited tolerance over a wider range of thermal and pH conditions. Genomic sequencing revealed that φAbp2 has a circular double-stranded DNA genome with no sequence similarity to our previously isolated φAbp1. Eighty-eight putative open reading frames (ORFs) encoding 41 proteins of known function and 47 of unknown function were identified, and the G/C content was 37.84%. φAbp2 is a new member of the subfamily Peduovirinae of the family Myoviridae. Its genome sequence is very similar to that of the A. baumannii phage LZ35.