-Natural Phages or Natural mutant Phages
-Phages that are modified by genetic engineering
-Virolysins (phage-encoded lytic enzymes also called lysins or endolysins)
From:
Recent Patents on Biotechnology 2009, 3, 000-000
"Production and Application of Bacteriophage and Bacteriophage-Encoded Lysins"
Noémie Manuelle Dorval Courchesne, Albert Parisien, Christopher Q. Lan
Department of Chemical and Biological Engineering, The University of Ottawa, Ottawa, ON, Canada K1N 6N5
".... it was reported that sub-lethal concentrations of certain antibiotics could substantially stimulate the host bacterial cell's production of virulent phages. For example, a low dosage of cefotaxime, a cephalosporin, increased an uropathogenic E.coli strain's production of the phage MFP by more than 7 fold. This phenomenon, which is designated as Phage Antibiotic Synergy (PAS), was observed in diverse hostphage systems. A common characteristic of these antibiotics is that they inhibit bacterial cell division and trigger the SOS system. The PAS phenomenon was found to be directly related to the formation of filamentous (elongated) cells under the stress of sub-lethal antibiotics. It was hypothesized that there has been an evolutionary selection for phages that can more efficiently cannibalize host cells that are unable to further divide. It was further suggested that if this is true, then the optimal conditions for phage multiplication may not be exponential cell growth as is widely believed, but rather a terminal burst of phage production in a stressed cell population that would soon die anyway. This observation provided the foundation for two recent patents exploiting the PAS phenomenon for enhanced phage production.
Applications of phages and virolysins include treatment and prevention of bacterial infections, detection of pathogens in foods and other samples, and decontamination of foods and medical devices.
Phages can also be utilized for a diversity of other applications such as in targeted drug delivery and in preventing biofilm formation in industrial processes".
