A protein discovered in human breast milk, which goes by the Shakespearean-sounding acronym, HAMLET, reportedly fights drug-resistant bacteria when added to antibiotics. The researchers say HAMLET could be used to boost the effectiveness of medications against the rising number of drug-resistant and dangerous bacteria.
HAMLET is short for Human Alpha-lactalbumin Made Lethal to Tumor cells. The human milk-protein complex has proved to be an effective weapon against cancer cells by destroying vital structures within each cell called mitochondria, biochemical powerplants which are responsible both for cellular energy and the processes that lead to cell death.
Researchers have found that HAMLET can do the same damage to the mitichondria in the cells of drug-resistant bacteria.
Anders Hakansson, a microbiologist and immunologist at the State University of New York at Buffalo, discovered HAMLET while looking for substances in human breast milk that protect newborns against upper respiratory infections.
Neither HAMLET nor antibiotics alone can kill drug-resistant pathogens, according to Hakansson. But the cell-disrupting protein and drug combine to form a powerful new anti-microbial weapon.
“So, it’s something that generally weakens the cell so that a number of different antibiotics will be able to have a better access to its targets and kill better," he said.
So far, Hakansson and colleagues have demonstrated the killing effect of HAMLET as an additive or adjuvant, to antibiotics both in the test-tube and in mice they infected with Staphyloccocus aureus, or MERSA. That's a multi-drug resistant strain of bacteria found both in and outside of hospitals, that causes a variety of potentially fatal infections in humans.
“The good news with this is that it can be used generally with essentially any kind of treatment, with any antibiotic - even if the organism appears to be sensitive - because it will be more sensitive if our protein is present," he said.
While the HAMLET protein in the experiments came from human milk, Hakansson says there’s an almost identical protein complex in cow’s milk which can also be used to fortify antibiotics.
Hakansson says developing new antibiotics is becoming less profitable for pharmaceutical companies, and as a result they have shown declining interest in this class of drugs. But he believes HAMLET offers a way to derive new use from existing drugs.
“Using an adjuvant that can be used together with any antibiotic to go back.and start using the old antibiotics that we know are safe and effective ..is very appealing," he said.
An article by Anders Hakansson and colleagues on the antibiotic additive HAMLET is published online in the journal PLoS ONE.