Pork products sold at retailers in Brazil contain antibiotic-resistant bacteria, according to a study funded by animal rights group World Animal Protection (WAP), providing potential evidence of overuse of the medicines in food livestock.

The study, which also looked at pork in three other countries, was conducted by the University of Sao Paulo on behalf of WAP in Brazil. It examined 100 meat samples from outlets owned by Carrefour, GPA and Walmart, WAP said.

"In all of the samples, the tests detected a generalized presence of bacteria resistant to antibiotics," WPA noted in a report last week describing the study's findings.