An investigation into an emerging strain of multidrug-resistant Salmonella Newport that was linked to beef obtained in the United States and soft cheese (likely unpasteurized) from Mexico is described in the August 23 issue of CDC’s Morbidity and Mortality Weekly Report. During June 2018–March 2019, CDC identified 255 people from 32 U.S. states who were infected with this strain, which appears to have spread from cattle in the United States and Mexico.
Testing showed that azithromycin and ciprofloxacin – two commonly prescribed oral antibiotics that are usually effective in treating severe Salmonella infections – might not work against this strain. Most patients with Salmonella infections recover without antibiotics, but those with severe infections need antibiotics. Resistant infections can be harder to treat, and patients may be at increased risk for developing serious complications.
Consumers should always cook beef to a safe internal temperature and check it with a food thermometer: 160°F for ground beef; 145°F for steaks and roasts, then let them rest for 3 minutes before cutting or serving. If you’re eating soft cheese such as queso fresco, make sure the label says “Made with pasteurized milk.”