ImmuCell, a biotech company in Portland, Maine, has developed a bacteriocin that treats dairy cows for mastitis, a disease that costs the dairy industry $2 billion a year. Riley says labs like hers can adapt phages and bacteriocins to target virtually any sort of human microbial infection too, with little risk of nurturing new resistance. “These are stable, hardy killing mechanisms that evolved 2 billion years ago,” she says.
Several clinical trials of phage therapy have already been successfully conducted in Poland, the nation of Georgia and Bangladesh. In the West, there have been successful phage trials for foot ulcers. No trials are underway for more serious infections, but a successful phage treatment of a critically multiresistant-infected patient in California in 2017 under Food and Drug Administration emergency rules has more researchers in the U.S. looking to develop phage treatments. One or more of these could move toward trials in the next few years, says Riley, including one for multi-resistant tuberculosis and another for pulmonary infections in cystic fibrosis patients. Bacteriocins are further behind. The U.S. government has promised to provide $2 billion for the effort to develop these alternatives, “but that's not nearly enough,” she says.
Cancer researchers are widely investigating drugs that can boost immune systems, and these immunotherapies could be promising in helping weakened patients fight off resistant bugs that try to take hold. Researchers have produced human antibodies in cows and other animals that can be injected into patients. Boston's Harvard-affiliated Brigham and Women's Hospital, in an emergency effort, reported injecting a combination of antibodies and antibiotics to save a patient with a drug-resistant infection, but the results weren't disclosed. Otherwise, little has been done to bring the approach to trials in infected patients. Researchers are also working on vaccines against resistant staph infections and other resistant bacteria, but these too are just research efforts. “These non-antibiotic treatments are still in the early stages of investigation,” says David Banach, who heads infection prevention at the UConn Health medical center in Farmington, Connecticut. “But we have to keep thinking of new approaches.”