Throughout the life and death (and nonlife) struggle between bacteria and bacteriophages, bacteria try to cut apart the genetic material that bacteriophages deploy when they try to commandeer bacterial resources. And now the bacterial weapon of choice, the immune system known as CRISPR, is starting to cut both ways. CRISPR components are being engineered into bacteriophages, arming them against pathogenic bacteria, including antimicrobial-resistant bacteria. In phage therapies, CRISPR-wielding bacteriophages may kill bacteria or compel them to carry out useful functions. For example, after suffering a few thrusts of the CRISPR sword, otherwise recalcitrant bacteria may have no choice but to express therapeutic proteins.
The swashbuckling ways of engineered phages are possible only though the patient work of highly disciplined researchers. For example, two research teams—one based at Rockefeller University, and one at the Massachusetts Institute of Technology (MIT)—began independent investigations of phage therapy that culminated in a close and productive collaboration.

https://www.genengnews.com/insights/phage-therapy-turning-the-tables-on-bacteria