Although it's widely known that food contaminated with Escherichia coli leads to often severe outbreaks of intestinal infection, recent evidence suggests that it can also lead to the development of urinary tract infection (UTI) in women. Epidemiologist Amee Manges, of McGill University in Montreal, Quebec, Canada, and colleagues, whose study appears in the January issue of Emerging Infectious Diseases, recently discovered that strains of E. coli originating in food, particularly chicken, may be a cause of UTIs, yet the microbes don't trigger intestinal disease.

"E. coli causes 80% to 90% of UTIs in communities," Manges said. Each year, 6 to 8 million cases of uncomplicated UTIs occur in the United States and cost the health care system up to $2 billion, she said, and some strains are becoming drug resistant. Large community outbreaks of UTIs in North America and Europe have been linked to E. coli, pointing to a possible environmental source of infection, such as contaminated meat.

Manges's team compared the genetic sequences and specific drug resistance of E. coli strains in urine collected from women with UTIs with strains found in chicken, beef, and pork purchased in local stores and restaurants. A number of strains from raw chicken and restaurant food exactly or closely matched those from women with UTIs. The findings suggest that "retail meat, specifically retail chicken meat, could be a reservoir for E. coli causing human extraintestinal infections."

Manges is still exploring how E. coli is transferred from food to people. The theory, she said, is that the bacteria take an indirect route, traveling from the intestinal tract to the anus; during sexual intercourse, they're carried from the anal area to the vagina and urethra, leading to infection. The best prevention, she told AJN, "is to follow hygienic practices in the kitchen, prevent cross-contamination between raw meat and other foods, and cook meat thoroughly."

Carol Potera