Each year, 6-8 million urinary tract infections (UTIs) occur in the U.S., according to the CDC, and this is just a small fraction of those occurring globally. Most infections – about 85% - appear to be caused by the bacteria Escherichia coli (E. coli). Until now, the offending bacteria were thought to be from the person’s own body (the gastrointestinal tract), not the environment. But a new report shows that this may not be the case at all.

The CDC analyzed the genomes of E. coli from women who were suffering from UTIs, and compared them to the E. coli genomes from food sources, including chicken, red meat, and pork. They found that the strains of bacteria from the UTIs matched those from one food source in particular: chicken. The bacteria were likely to have come from the chicken itself, rather than from human contamination during the food preparation process.

The authors also stress the concern about antibiotic-resistant bacteria, particularly as some of samples in the study were resistant to certain antibiotics. The FDA has recently called for a reduction in the use of common antibiotics in food animals, since their overuse in farms has widely been linked to the growing resistance of these bugs.

Antibiotic resistance is not only a health concern, but it’s an economic one, since infections often need to be treated multiple times or require more complicated measures. Organic farms have recently shown some promise as a method to reduce antibiotic resistance, particularly in bugs that are resistant to multiple forms of antibiotics.

It will take some time for farming and animal care practices to reflect the changes that are just beginning to be mandated. In the meantime, it’s extremely important to prepare your food safely, soaking and/or washing fruits and veggies well before eating, cooking meats thoroughly, and baking cookie dough before eating.

The study was carried out by researchers at McGill University and published in the March issue of the CDC’s Emerging Infectious Diseases.