The present invention includes compositions and methods for increasing antibiotic sensitivity and/or decreasing virulence in bacteria.

The present invention provides a virulent Pseudomonas fluorescens (P. fluorescens) phage ΦPf1901, and a phage ΦPf1901 preparation and an application thereof, and relates to the technical field of phage. The virulent P. fluorescens phage ΦPf1901 has an accession number of CCTCC M2019447. The virulent phage ΦPf1901 has a titer of (1.4-3)×10.sup.10 PFU/mL. The virulent phage ΦPf1901 has an optimal multiplicity of infection (MOI) value of 0.0001. The virulent P. fluorescens phage ΦPf1901 provided by the present invention exhibits very high specificity and lytic ability to P. fluorescens, which can be used to control P. fluorescens, with strong lytic and scavenging effects on a host.

The present invention provides a virulent Pseudomonas fluorescens (P. fluorescens) phage Pf1901, and a phage Pf1901 preparation and an application thereof, and relates to the technical field of phage. The virulent P. fluorescens phage Pf1901 has an accession number of CCTCC M2019447. The virulent phage Pf1901 has a titer of (1.43)10.sup.10 PFU/mL. The virulent phage Pf1901 has an optimal multiplicity of infection (MOI) value of 0.0001. The virulent P. fluorescens phage Pf1901 provided by the present invention exhibits very high specificity and lytic ability to P. fluorescens, which can be used to control P. fluorescens, with strong lytic and scavenging effects on a host.

The present invention is generally related to engineered bacteriophages expressing antimicrobial peptides or lytic enzymes or fragments thereof for targeting a broad spectrum of bacterial hosts, and for the long-term suppression of bacterial phage resistance for reducing bacterial infections. In some embodiments, bacteriophages express antimicrobial peptides or antimicrobial polypeptides (e.g. phage lytic enzymes) which are secreted from the host bacteria, or alternatively released upon lysis of the bacterial host cell. Aspects of the present invention also relate to the use of the engineered bacteriophages for the reduction of bacterial infections, both in a subject or for bioremediation purposes, in clinical settings and wound healing.