Chicken, turkey and pork sold in grocery stores may harbour Klebsiella pneumoniae, according to a new study. The research, which published in the journal Clinical Infectious Diseases, shows that contaminated meat may be an important source of human exposure to Klebsiella.

The U.S. food safety system has traditionally focused on a few well-known bacteria like Listeria, Salmonella and Campylobacter, which cause millions of cases of food poisoning every year.

The study found that 47 percent of the 508 meat products purchased from grocery stores in 2012 harboured Klebsiella—and many of the strains recovered were resistant to antibiotics.

Agricultural operations often give food animals antibiotics to make them grow faster and to prevent diseases, a practice that can create conditions ideal for the emergence of resistant strains of Klebsiella.

The team found Klebsiella, including resistant strains, comprised 10 percent of the 1,728 positive cultures from patients with either urinary tract or blood infections in the Flagstaff area. The researchers used whole-genome DNA sequencing to compare the Klebsiella isolated from retail meat products with the Klebsiella isolated from patients and found that some isolate pairs were nearly identical.