A microbial standoff beneath the prickly spines of European hedgehogs may have bred a dangerous drug-resistant pathogen long before the era of antibiotic use in humans. Antibiotic use, without a doubt, accelerates drug resistance in bacteria that colonize humans, according to Jesper Larsen, a veterinarian at Statens Serum Institut in Copenhagen. However, he claims that these microbes had to acquire the resistance genes from somewhere, and scientists aren't sure where the majority of these genes come from. Now, for one type of methicillin-resistant Staphylococcus aureus, or MRSA, Larsen, and colleagues have tracked its evolution to hedgehogs hundreds of years ago.