Urinary tract infections (UTI) are a serious health problem affecting millions of people each year. In fact, they are the second most common type of bodily infection, accounting for about 8.3 million doctor visits annually. Escherichia coli–a family of bacteria that includes E. coli O157 and other shiga-toxin producing strains, as well as certain generic strains that can reside quite peacefully in the human colon–is the most common cause of urinary tract infections. New research suggests that, even for strains associated with UTI rather than gastrointestinal disease, meat may be the ultimate reservoir.
Researchers from Denmark conducted the study, and will soon publish the results in the publication "Foodborne Pathogens and Disease." In the study, abstract available here, researchers studied the serogroups and antimicrobial resistance characteristics of E. coli isolates (pure bacteria examined for genetic characteristics and uniqueness) from various sources, including community-dwelling humans, broiler chicken meat, broiler chickens, pork, and pigs.
A total of 964 geographically and temporally matched E. coli isolates from UTI patients (n=102), community-dwelling humans (n=109), Danish (n=197) and imported broiler chicken meat (n=86), Danish broiler chickens (n=138), Danish (n=177) and imported pork (n=10), and Danish pigs (n=145) were tested for phylogroups (A, B1, B2, D, and nontypeable [NT] isolates) and antimicrobial susceptibility. Phylogroup A, B1, B2, D, and NT isolates were detected among all groups of isolates except for imported pork isolates. Antimicrobial resistance to three (for B2 isolates) or five antimicrobial agents (for A, B1, D, and NT isolates) was shared among isolates regardless of origin.
Using cluster analysis to investigate antimicrobial resistance data, the researchers found that UTI isolates always grouped with isolates from meat and/or animals. Researchers detected B2 and D isolates, that are associated to UTI, among isolates from broiler chicken meat, broiler chickens, pork, and pigs. Although B2 isolates were found in low prevalences in animals and meat, these sources could still pose a risk for acquiring uropathogenic E. coli. Further, E. coli from animals and meat were very similar to UTI isolates with respect to their antimicrobial resistance phenotype. The researchers believe that the study provides support for the hypothesis that a food animal and meat reservoir might exist for UTI-causing E. coli.