What is the fine-grained topic of the following text: The U.S. Food and Drug Administration (FDA) recently updated a Safety Communication regarding Mycobacterium chimaera (M. chimaera) infections associated with the use of the 3T heater-cooler in U.S. patients who have undergone cardiothoracic surgeries (surgeries involving the heart, lungs, esophagus and other chest organs). Only return the topic.
FDA Safety Communication on M. chimaera infections from 3T heater-cooler use in cardiothoracic surgeries