A novel form of deadly drug-resistant bacteria that hides from a standard test has turned up in Europe. Researchers found the so-called MRSA strain in both dairy cows and humans in the United Kingdom, suggesting that it might be passed from dairies to the general population. But before you toss your milk, don't panic: The superbug isn't a concern in pasteurized dairy products. MRSA, short for methicillin-resistant Staphylococcus aureus, is a drug-resistant form of the widespread and normally harmless S. aureus bacteria. Many people walk around with MRSA in their noses or on their skin yet don't get sick. But...