Phage Therapy Pt. 2

So what have we learned about bacteriophages? While early phage therapy proved inconsistent because phages were expelled from the host's immune system before they could properly eliminate microbial infection. In fact, it was shown by Carl Merril at the NIH in the 70s that the bacteriophage were cleared from the systems of mice without even using antibodies. By 1996, Merrill published a paper stating that certain mutants of lambda phage could circulate long enough to have therapeutic potential. Longer circulation periods in hosts meant that the mutant phage could evade the hosts immune system which in the case of bacteriophage, is a great thing.

In addition, it was shown that when bacteriophage lyse gram-negative bacteria there is a release of endotoxin that is so damaging to the host organism that it negates the benefit of the page action against the bacteria. In 2003, Steven Hagens and Udo Blasi at the Vienna Biocenter were able to build a phage that could kill the gram-negative bacteria with negligible release of endotoxin through the use of a restriction endonuclease. There was no compromise in killing efficiency.