An outbreak of drug - resistant salmonella across the US in 2018 - 19 may have been caused by a 41 % spike in the use of antibiotics in cows the previous year . To reduce the risk of infections—drug resistant or not—health officials advise consumers not to eat cheeses made from unpasteurized milk and to make sure beef reaches safe cooking temperatures: 145°F (62.8°C) for steaks and roasts followed by a 3-minute rest time, and 160°F (71.1°C) for ground beef or hamburgers. The strain , which affected 225 people and killed 40 , was found by the Centers for Disease Control and Prevention ( CDC ) to be resistant to numerous antibiotics , including azithromycin , which is often used to treat the infection . But a 23 February 2019 FDA report noted that the disease , which was traced back to US beef and Mexican cheese , followed an increased use of macrolide antibiotics , which include calcium , by cattle farmers in 2016 - 17 .
An outbreak of drug - resistant salmonella across the US in 2018 - 19 may have been caused by a 41 % spike in the use of antibiotics in cows the previous year . The strain , which affected 225 people and killed 40 , was found by the Centers for Disease Control and Prevention ( CDC ) to be resistant to numerous antibiotics , including azithromycin , which is often used to treat the infection . But a 23 February 2019 FDA report noted that the disease , which was traced back to US beef and Mexican cheese , followed an increased use of macrolide antibiotics , which include calcium , by cattle farmers in 2016 - 17 .