Phage Therapy of Vibrio Harveyi 35species should not cause phage conversion since Vibrio species is not a normal
flora in human body. Thus, we should consider studying the safety of the
temperate phage to treat bacterium infection case by case if we are going to
apply temperate phage in vivo treatment. In addition, it is a better alternative to
have two or more kinds of temperate phage which are permissive to infect the
same strain of bacteria. How to use multi-phage treatment of any problem-
causing bacterium is a major question. Whether using all the phages
simultaneously or at different time does better, requires further investigation.
The ideal is to prevent any lysogens which become resistance to those phages.
Concerning the safety of phage therapy, the main concern is the
phenomenon of phage conversion. This can occur in case of using temperate
phage for the treatment but not the case for virulent phage. However, the
phage conversion should be concern only in the case that the infectious agent
is the same specie as the normal florae as a example of E. coli as mentioned
above. In the meantime, it is unlikely that bacteriophage can be pathogenic
directly to animal and human because phage is a bacterial infectious agent not
eukaryotic cell. However, to know all well, we do need to keep learning
further.
PROPOSAL TO DEVELOP PHAGE TREATMENT
As mentioned concerning the problems in using natural temperate phage
for treatment, the concept to eliminate or knock out any particular gene(s) that
create the lysogenic infection pathway can be the strategy to overcome these
problems. Theoretically, genomic modification technique may be possible to
convert a temperate phage to a virulent phage in the research laboratory (Wolf
and Woodside, 2005). The process can be done by sequencing the particular
phage genome to localize the involved lysogenic genes and subsequently alter
or delete them to prevent lysogenic infection in bacterial cell. This can be a
way to covert the temperate phage to be virulent phage for treatment of
bacterial infection and contamination.
However, the major concern in using phage as a tool to fight against
bacterium is the specificity of phage infection in the bacterium cell. Research
shows that the phage infection in bacterium is a phenomenon of strain specific,
not specie specific (Nagy, 1974; Rakhuba et al., 2010; Chibani-Chennoufi,
2004b). This means if there is more than one strain of pathogenic bacterium,
we need to obtain all the strains of phage that can infect the pathogenic
bacteria. In this case, it is necessary to collect all phage species in order to