A CBC investigation has found what it described as "worrying levels" of antibiotic-resistant bacteria on imported shrimp bought at major grocery stores across Canada.

To test for the potential of antibiotic-resistant bacteria, the news site bought 51 frozen shrimp products from major grocery stores in Calgary, Toronto, Saskatoon and Montreal, and sent them to a special lab at the University of Saskatchewan for analysis.

Nine of the products — or 17 percent — were found to be carrying bacteria, such as E. coli and staph aureus, that showed resistance to at least one antibiotic, the news site found.

While Canada does inspect the seafood coming into the country, including shrimp, inspectors are only testing for antibiotic residue — not antibiotic-resistant bacteria.