There's limited phage therapy because the outcomes are not always predictable. From the bacteria's viewpoint they are at war with other microbes from yeasts and viruses to competing bacteria. Apex predators in the single cell world are phages so a bacteriophage would be needed to attack and consume P.a. These exist in uncountable varieties and most of them are unsuitable in humans for the purpose of eliminating a certain type of infection.
This goes full circle to the discovery of antibiotics. Discovered, not made or modified, antibiotics are the chemical weapons that one organism like the Penicillium r. mold uses to kill pathogenic bacteria and not our cells. Sending one bacteria to kill another is part of the art of gastronomy or the preparation and preservation of fine foods. Gastronomy can thank a lot of dead people who paved the way to whey and yogurt by trial and sometimes fatal error. The path from antiseptic to antibiotics went through microbiology or the study of microbial civilization including its warfare. Humans have specific types of infections that pass from person to person but our parakeet or cat isn't at risk. We've been studying bacteria for over two centuries. That's a lot of information that began with seeing animalcules or protozoa in a drop of pond water. We have learned what kills what and harvested their chemical weapons.
Whether it's multiple antibiotics or an engineered microbe that excretes a biofilm solvent and whatever else is lethal to P.a., the problems are the same. Long before we had the technology to inject genes into bacteria, careful and imaginitive breeding, engineered everything from more productive corn to more productive microbes from which we extract antibiotics.
With the genetic tools today, the outcomes of genetic engineering holds tremendous potential for phage therapy. The two challenges of phage therapy are, resistance to consuming GMO's (Genetically Modified Organisms) be it blackberries or phage therapy and modeling the long term stability of a single celled bacteriophage. Of our white blood cells, we have many types of stable bacteriophages, genetic modification of this type of cell isn't what phage therapy is about. It would be a great tool in MDR bacterial eradication. I don't want to be negative about a promising technology but infecting us with one bacteria to kill a other carries the potential for evolving to feed on us when stocks of P.a. run out.
This is why doctors don't have a lot of enthusiasm for intentional infliction of a live bacteria in us. We are closing in on the intricate biochemistry of bacteria. In fact the complete genomes of several bacteria have been translated into the functions and processes at the molecular level. We are gods of the bacteria, in terms of the compendium of knowledge and our deep understanding of how bugs work.
Every tool in fighting MDR infections should be considered and reconsidered.
LL
