The substance in breast milk that helps stop the MRSA superbug

A molecule derived from human breast milk makes the antibiotic-resistant “superbug” MRSA susceptible to antibiotics again, according to a study at the University of Buffalo in the US.

The protein complex contains the common milk protein alpha-lactalbumin coupled to fatty acids, and goes by the natty name of Hamlet, or the more tongue-twisting “human alpha-lactalbumin made lethal to tumour cells”, because of its ability to kill cancer cells.

Dr Anders Hakansson and colleagues have recently discovered that Hamlet has a few other tricks up its sleeve. It can kill some bacteria and, in the case of their new study published in PLoS ONE , it can even make antibiotic-resistant MRSA sensitive to antibiotics. When the researchers exposed MRSA in the lab or in the nasal tissues of mice to antibiotics along with Hamlet, they found the approach was more effective at halting the MRSA than using antibiotics alone.

“We believe this strategy may be fruitful to increase the treatment arsenal against bacterial infections so that we can again use older and safer antibiotics,” Hakansson says. “It will also have a large market as it will be used together with antibiotic treatment rather than stored away as a ‘last-resort’ type antibiotic.”

Hakansson describes as a “first possibility” that Hamlet could potentially be used topically in the treatment of wound infections.

“Additionally, it is possible that it could be inhaled and also that it could be eaten to have an effect in the lung tissue and in the stomach lining against bacterial infections there,” he says.

“However, these are things that we have thus far no proof of principle to support, but are working hypotheses that we hope to develop.”