A drug-resistant form of e. coli may be working its way toward your summer barbecues.

RODALE NEWS, EMMAUS, PA—There are hundreds of strains of E. coli bacteria, and most of them are harmless. At the worst, they cause a few days of digestive discomfort. However, new research has revealed that an emerging strain, known as ST131, is on its way to becoming a drug-resistant superbug that leaves doctors with few treatment options. Most drug-resistant strains in the past fortunately didn’t cause a lot of problems. Not so with ST131. This strain is both virulent and largely unresponsive to antibiotics.

THE DETAILS: In the study, carried out by U.S. infectious-disease experts and published online in Clinical Infectious Diseases, researchers analyzed data from patients hospitalized with E. coli infections around the country in 2007. The strain responsible for the majority of these infections? ST131. Currently, the pathogen is already resistant to certain antibiotics, but researchers believe that if it adds one more resistance gene, it will be virtually untreatable. This means our immune systems will be our only weapon against it, which is particularly concerning for the young, old, and those with already suppressed immunity.

WHAT IT MEANS: In the past, E. coli outbreaks have prompted recalls of everything from lettuce and beef to cookie dough. And while most E. coli cases result in a few hours of uncomfortable stomach cramps and more frequent trips to the bathroom, the emergence of more virulent strains is proving to be more serious. In worst-case scenarios, it’s fatal. Foodborne illnesses are also incredibly costly. A report released earlier this year found that these illnesses are costing the U.S. $150 billion a year.

The authors of this latest study say that more research is needed to determine where this strain is coming from, but other scientists have linked virulent E. coli strains, such as 0157:H7, to concentrated animal-feeding operations—in other words, factory farms.