Phage therapy is using bacteria to kill other bacteria. It was done before penicillin then stopped except for in poor Eastern European countries like Georgia. It’s the last resort for people all over the world who have no other options left due to resistance. You have to fly there at own expense and plan to stay until they figure out by testing what will kill your bacteria. Google phage therapy. A doctor in Texas got special permission to get some phage from that country to use on wounds that would not heal and resistance to antibiotics. It works. Our govt research labs are investigating its use here.