NEW YORK (GenomeWeb) – An Escherichia coli strain that is adapted to poultry — and sometimes found in retail chicken and turkey products — appears capable of causing urinary tract infections (UTI) in humans, according to research published in mBio yesterday.
"This particular E. coli strain appears capable of thriving in poultry and causing disease in people," first author Cindy Liu, a researcher affiliated with George Washington University, Northern Arizona University, and Translational Genomics Research Institute, said in a statement, noting that "[p]oultry products could be an important vehicle for bacteria that can cause diseases other than diarrhea."
Liu and her colleagues focused on the E. coli sequence type 131, which has "emerged explosively since the early 2000s," becoming a well-known uropathogen that is often resistant to multiple antibiotics. For their new study, the investigators used multilocus sequence typing (MLST), core genome SNP-based phylogenetics, and other approaches to systematically analyze thousands of E. coli isolates collected from meat products and clinical cases over a year in Flagstaff, Arizona.
The team detected E. coli in one form or another in nearly 80 percent of the 2,452 meat samples considered, including 27 E. coli ST131 isolates. All but two of the ST131 isolates fell in the so-called H22 lineage, the group explained, and 24 of the 25 E. coli ST131-H22 isolates originated in retail poultry products. Similarly, most carried a CoIV plasmid that has been linked to poultry adaptation.
On the clinical side, meanwhile, the researchers found 24 ST131-H22 isolates across the nearly 2,000 E. coli-positive samples collected. And some 25 percent of those isolates contained the CoIV plasmid, falling in a phylogenetic cluster with the ST131-H22 representatives uncovered in the poultry samples.
With the help of molecular clock analyses and other approaches, they found further evidence for poultry-to-human transmission of the bug, along with at least half a dozen CoIV introductions into the E. coli lineage over the past several decades.
"In the past, we could say that E. coli from people and poultry were related to one another, but with this study, we can more confidently say that the E. coli went from poultry to people and not vice versa," corresponding author Lance Price, an environmental and occupational health researcher at George Washington University, said in a statement.
Based on their current results, Price added, the team is now looking at the possibility that other forms of E. coli that have been found in food products might contribute to urinary tract infections as well.
"This is not an easy question to answer but an extremely important one," he said.