Chloramphenicol-resistant Salmonella newport traced through hamburger to dairy farms

An epidemiological and clinical study of the causation of salmonella infections in humans in California found that salmonella was present in beef carcasses received for slaughter and that chloramphenicol-resistant salmonella from dairy farms was associated with the use of chloramphenicol at these farms. It was concluded that food animals are a major source of antimicrobial-resistant salmonella infections in humans and that these infections are due to antimicrobial usage on farms.(wz)