A method of recovering viable phage from, for example, a crude phage preparation such as a lysate resulting from amplification of phage in bacterial cell culture is disclosed. The method may be universal; that is, applicable to the purification of a broad range of phage species and strains. The phage product resulting from the method may have an acceptably low endotoxin titer (e.g. less than 500 EU/ml) and sufficiently high phage titer (e.g. >1?10.sup.9 PFU/ml) for use in therapeutic applications.

A method of manufacturing of a dry mixture of at least one yeast and/or yeast derivative and at least one bacteriophage, where the mixture being in the form of solid entities, and each solid entity is composed of at least one yeast and/or at least one yeast derivative and at least one bacteriophage and possibly at least one drying excipient, where the method is done by the mixing of at least one yeast and/or yeast derivative and at least one bacteriophage in suspension and the drying of this mixture. Also, a dry mixture of at least one yeast and/or yeast derivative and at least one bacteriophage, which is in the form of solid entities, where each solid entity is composed of at least one yeast and/or at least one yeast derivative and at least one bacteriophage and possibly at least one drying excipient and uses thereof.

The utility of directed-in vitro evolution of phages in a phage cocktail, i.e., phage training, using panels of multidrug resistant strains of P. aeruginosa or K. pneumoniae was demonstrated effective for the development of phages having broader host ranges of MDR P. aeruginosa or K. pneumoniae. The phage clones obtained by this method have lytic activity against more host strains than their parental phages. Sequencing results of the trained phages showed significant genetic changes from the parental phages. Some trained phages having lytic activity in an expanded range of MDR bacterial strains was proved to be stable, indicating the genetic changes that accumulated were not readily reversible. One of the phage clones showing host range stability was selected and incorporated into a previously used phage cocktail. The new phage cocktail provided improved therapeutic efficacy in a mouse model of wound infection. Taken together, these results show the utility of in vitro phage training in the development of more efficacious phage therapeutics to target the critical drug-resistant pathogens P. aeruginosa as well as K. pneumoniae. Based on these results, a new method for phage training and pharmaceutical composition comprising one of the trained phages is suggested.

The present invention relates to a method for in vitro amplification of a linear virus genome, in particular a bacteriophage, expression and self-assembling of the virus, in particular the bacteriophage, in a cell-free expression system as well as a virus 5 or bacteriophage provided by such methods. Further aspects of the invention relate to a synthetic bacteriophage and the use thereof.

Engineered bacteriophages comprising polynucleotides encoding heterologous proteins under the control of repressible promoters are provided. Also disclosed are processes for producing the engineered bacteriophages, pharmaceutical compositions comprising the engineered bacteriophages and therapeutic and preventive methods using the engineered bacteriophages.

This invention provides a robust fermentation process for the expression of a capsid protein of a bacteriophage which is forming a VLP by self-assembly, wherein the process is scalable to a commercial production scale and wherein the expression rate of the capsid protein is controlled to obtain improved yield of soluble capsid protein. This is achieved by combining the advantages of fed-batch culture and of lactose induced expression systems with specific process parameters providing improved repression of the promoter during the growth phase and high plasmid retention throughout the process.