Antibacterial discovery: how scavengers avoid infection and what we can learn from them

Antibacterial discovery has become a pressing global challenge. Rising antibiotic resistance and difficult-to-treat infections mean we urgently need new antibacterial drugs and infection prevention measures. Food production problems such as bacterial crop disease and food spoilage are driving demand for innovations too. Many antibacterial products in current use come from nature, two examples being the antibiotic streptomycin and the food preservative lysozyme. Antibacterial production is thought to have evolved for self-defence, helping small organisms repel competitors and large organisms avoid infection. In small organisms inhabiting a larger one, for example friendly gut microbes, antibacterial molecules may serve both of these functions. This inspired us to consider scavengers such as vultures, hagfish and blowflies. Scavengers feed on decomposing animal carcasses, a diet expected to contain disease-causing bacteria. We were curious if this expectation is supported by scientific data. We also wanted to know if scavengers or their gut microbes have evolved any special defences. And if, like streptomycin or lysozyme, these defences could be developed for human use. Our study set out to answer these questions. We began by cataloguing the diets of over 600 species of scavenger, then cross-referenced this information with current scientific research on infectious disease, immunology and biotechnology.