Disclosed herein are novel synthetic bacteriophages and bacteriophage compositions, methods of production thereof, and therapeutic uses thereof.

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 relates, in part, to engineered viruses (e.g., engineered phages), phage cocktails, and methods of producing and/or identifying viruses for targeting pathogenic bacteria.

The invention relates to a method for reducing the population of at least one intestinal and/or gastrointestinal species of bacteria, the method comprising the following steps: a) providing a biological sample containing bacteria of at least one intestinal and/or gastrointestinal species of bacteria, the intestinal and/or gastrointestinal species of bacteria directly or indirectly influencing a psychological, neurodegenerative and/or neurological illness and/or disorder of a host organism; and b) providing bacteriophages of at least one species of bacteriophages that are specific to the intestinal and/or gastrointestinal species of bacteria and that comprise at least one nucleic acid functionally associated with a promotor and/or a regulatory element; and c) contacting and incubating the biological sample with the bacteriophages, the incubation continuing until the population of the intestinal and/or gastrointestinal species of bacteria has been reduced by at least 70%.

In alternative embodiments, provided are products of manufacture and kits, and methods, to enrich for and/or isolate microbes such as viruses and/or phages capable of targeting, e.g., binding to, targeting, and/or killing or otherwise making non-viable or non-pathogenic, specific or desired microbes such as bacteria. In alternative embodiments, provided are products of manufacture comprising: a virus and/or a phage (a bacteriophage). In alternative embodiments, provided are products of manufacture and kits containing a virus and/or a phage (a bacteriophage) enriched for, selected for or isolated by a method as provided herein, or a microbe containing a virus and/or a phage (a bacteriophage) enriched, selected for and/or isolated by a method as provided herein.

Bacteriophage compositions and therapeutic uses thereof. In particular, compositions of lytic bacteriophages that are capable of lysing Propionibacterium acnes (P. acnes) bacterial strains associated with acne and biofilms, thereby treating or preventing acne and biofilms.

Compositions for affecting the intestinal microbiome of a mammalian subject can include a pharmaceutically-acceptable carrier and greater than or equal to 1×10.sup.4 PFU/mL or PFU/mg of bacteriophage having a tropism that includes an obesogenic and/or inflammatory bacterium associated with an intestinal microbiome of a mammal. Processes for preparing the disclosed compositions can include isolating the bacteriophage from an environmental source, characterizing the bacteriophage, and combining the bacteriophage with the pharmaceutically acceptable carrier at greater than or equal to 1×10.sup.4 PFU/mL or PFU/mg. Methods can include administering the disclosed compositions to a mammalian subject with or without co-administration of the disclosed probiotics. Administering the disclosed compositions can reduce a concentration of obesogenic and/or inflammatory bacteria in the intestinal microbiome of the mammalian subject, promote or induce weight loss, reduce inflammation, support metabolic health, and/or support a healthy balance/diversity within the intestinal microbiome of the mammalian subject.

Methods of diagnosing and treating patients afflicted with acne, including diagnosing one as having acne if the individual possesses RT4, RT5, RT7, RT8, RT9, or RT10. Methods for treating acne include administering an effective amount of a drug specifically targeting RT4, RT5, RT7, RT8, RT9, or RT10, such as small molecules, antisense molecules, siRNAs, biologics, antibodies, phages, vaccines, or combination thereof.

The invention relates to methods, uses, systems, arrays, engineered nucleotide sequences and vectors for inhibiting bacterial population growth or for altering the relative ratio of sub-populations of first and second bacteria in a mixed population of bacteria. The invention is particularly useful, for example, for treatment of microbes such as for environmental, medical, food and beverage use. The invention relates inter alia to methods of controlling microbiologically influenced corrosion (MIC) or biofouling of a substrate or fluid in an industrial or domestic system.

The invention relates to vectors and methods for de-repressing Cas systems in host cells.