A group of Democratic senators is stepping up pressure on the co-chairs of the Interagency Task Force for Combating Antibiotic-Resistant Bacteria to address gaps in FDA's efforts to stem the overuse of antibiotics in food animals. The senators initially wrote to the co-chairs last December, but did not receive a response, and they followed up with a letter last week. The Monday (Aug. 17) letter -- sent by Sens. Elizabeth Warren (MA), Dianne Feinstein (CA) and Kirsten Gillibrand (NY) --...