Biological characterization and genomic profiling of a novel Providencia phage isolated from farm effluents.

A Providencia strain was isolated from farm effluents and used as a host to isolate a bacteriophage named A06. A double-layer agar plaque assay was used to determine the optimal multiplicity of infection (MOI), construct a one-step growth curve, evaluate the temperature and pH stability of the phage, and assess its in vitro antibacterial activity and lysis efficiency. Whole-genome sequencing, functional annotation, and comparative genomics analysis were used to analyze its biological features and determine its taxonomic position. Bacteriophage A06 has a circular DNA genome with 58 open reading frames (ORFs). The optimal MOI was determined to be 100, and a one-step growth curve showed the latent period to be 40 minutes and the lysis period to range from 40 to 90 minutes. Bacteriophage A06 exhibited a high degree of thermal stability and pH tolerance, and genomic analysis indicated that it represents a new species within the genus Kakivirus of the family Autoscriptoviridae.