New research suggests that retail mean may be a source of disease causing Klebsiella.

Researchers at George Washington University and Milken Institute SPH found that chicken, turkey and pork sold in grocery stores may be an important source of human exposure to disease-causing bacteria known as Klebsiella pneumonia.

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 research published suggests that Klebsiella may need to be added to the list of risky bugs in food products.

"This study is the first to suggest that consumers can be exposed to potentially dangerous Klebsiella from contaminated meat," Lance B. Price, lead author of the study, said in a statement. "The U.S. government monitors food for only a limited number of bacterial species, but this study shows that focusing on the 'usual suspects' may not capture the full scope of foodborne pathogens."

For the study, researchers compared K. pneumoniae isolates from retail meat products and human clinical specimens to assess their similarity based on whole genome sequencing. They first looked at turkey, chicken and pork products being sold in nine major grocery stores in Flagstaff, Arizona, in 2012. Then the team analyzed urine and blood samples taken from Flagstaff area residents who were suffering from infections during the same time period.

They found that 47 percent of the 508 meat products purchased from grocery stores in 2012 harbored 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.

They also found that the disease-causing bacteria, including resistant strains, comprised 10 percent of the 1,728 positive cultures from patients with either urinary tract or blood infections.

"As an infectious disease doctor, I have encountered Klebsiella pneumoniae in my patients. We tend to think of this organism as being one that individuals carry naturally, or acquire from the environment," said James R. Johnson, a co-author of the study. "This research suggests that we also can pick up these bacteria from the food we eat."

The findings are detailed in the journal Clinical Infectious Diseases.