Australia's food supply risks carrying aggressive and drug resistant strains of disease unless a class of antibiotics used in pigs and cattle are banned, a leading infectious diseases expert says.

Australia has relatively low rates of antibiotic resistance in food-borne, gastro-inducing bacteria such as salmonella, campylobacter and E. coli.

But Professor Peter Collignon, from the Australian National University, said effective treatment for these diseases risked being undermined by a failure to ban third and fourth-generation antibiotics, called cephalosporins, in livestock.

''We have very low levels of E. coli resistant to last-line antibiotics in Australia compared with everywhere else in the world,'' Professor Collignon said.

''We need to keep it that way. That means a ban of this class of drug in food animals and not importing meats and foods that may already contain those superbugs.''