Salmonella in sub-Antarctica: low heterogeneity in salmonella serotypes inSouth Georgian seals and birds

The number of human visitors to Antarctica is increasing rapidly, and with it a risk of introducing infectious organisms to native animals. To study t he occurrence of salmonella serotypes in sub-Antarctic wildlife, faecal sam ples were collected from gentoo penguins, macaroni penguins, gray-headed al batrosses, black-browed albatrosses and Antarctic fur seals on Bird Island in the South Georgian archipelago during the austral summer of 1996 and 199 8. In 1996, S. havana, S. typhimurium and S. enteritidis were isolated from 7% of gentoo penguins and 4% of fur seals. In 1998, however, 22% of fur se als were found to be infected with S. havana, S. enteritidis and S. newport . All isolates, except one, showed identical pulsed-field gel electrophores is-patterns within each serotype, irrespective of sampling year and animal reservoir. No significant antibiotic resistance was found. The very low het erogeneity in the salmonella isolates found could either indicate a high ge netic adaptation of the bacteria to the environment or a recent introductio n of salmonella into the area.