Epidemiology and Infection



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


H. PALMGREN a1, D. McCAFFERTY a6, A. ASPÁN a5, T. BROMAN a1a2, M. SELLIN a2, R. WOLLIN a7, S. BERGSTRÖM a3 and B. OLSEN a1a4c1
a1 Department of Infectious Diseases, Umeå University, S-901 87 Umeå, Sweden
a2 Department of Bacteriology, Umeå University, S-901 87 Umeå, Sweden
a3 Department of Microbiology, Umeå University, S-901 87 Umeå, Sweden
a4 Department of Infectious Diseases, Kalmar County Hospital, S-381 95 Kalmar, Sweden
a5 Department of Bacteriology, National Veterinary Institute, SE-750 07 Uppsala, Sweden
a6 British Antarctic Survey, National Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 OET, UK
a7 Department of Bacteriology, Swedish Institute for Infectious Disease Control, SE-171 82 Solna, Sweden

Abstract

The number of human visitors to Antarctica is increasing rapidly, and with it a risk of introducing infectious organisms to native animals. To study the occurrence of salmonella serotypes in sub-Antarctic wildlife, faecal samples were collected from gentoo penguins, macaroni penguins, gray-headed albatrosses, black-browed albatrosses and Antarctic fur seals on Bird Island in the South Georgian archipelago during the austral summer of 1996 and 1998. 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 seals were found to be infected with S. havana, S. enteritidis and S. newport. All isolates, except one, showed identical pulsed-field gel electrophoresis-patterns within each serotype, irrespective of sampling year and animal reservoir. No significant antibiotic resistance was found. The very low heterogeneity in the salmonella isolates found could either indicate a high genetic adaptation of the bacteria to the environment or a recent introduction of salmonella into the area.

(Accepted July 7 2000)


Correspondence:
c1 Author for correspondence: Department of Infectious Diseases, LSK, SE-391 85 Kalmar, Sweden.


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