Salmonella contamination of rubber boots worn on dairies

Rubber boots were cultured for Salmonella after being worn in calving, hospital and fresh cow pens on 27 selected dairies in California, USA. Dairies were selected on the basis of willingness to cooperate, previous isolation of Salmonella from bulk tank milk, or recent history of clinical salmonellosis. Six salmonella serotypes, including Salmonella typhimurium and Salmonella newport, were isolated from boots worn on 12 of the dairies. Salmonella was re-isolated from one of four boots 48 h after they were casually washed. Veterinarians should be aware of the potential to transfer microorganisms from one location to another on boots and inform dairymen as they develop biosecurity plans to minimize this hazard.