Summary
Penguins breeding in the Antarctic have evolved in the most isolated ecosystem in the world, receiving only very minimal exposure to infectious agents from other regions. However, yearly expansion of human activity in the region, seen both in tourism and science, and expected changes in climate associated with global warming both increase the risk of introduction of infectious agents and cause stress and disruption to normal activities, which can result in increased susceptibility to infection. While much research has been carried out into the breeding biology and foraging ecology of Antarctic penguin species, little is known about the disease status of wild populations. This lack of baseline information on the normal endemic microflora of these animals makes it difficult to evaluate any changes in microflora. To obtain such information and develop a monitoring scheme, we have collected faecal and blood samples from over 1000 Adelie (Pygoscelis adeliae) and Emperor (Aptenodytes forsteri) penguins from various sites in Eastern Antarctica and from Terra Nova Bay in the Ross Sea. While no serum antibodies to Newcastle Disease virus or Avian Influenza virus have been detected to date, 97% of Emperor penguin chicks and approximately 8% of adult Adelie penguins from all locations possess neutralising antibodies to Infectious Bursal Disease virus, suggesting this virus is widespread in the Antarctic penguin population. Bacterial analysis has revealed the presence of aerobic and anaerobic bacteria in all faecal samples including a number of apparent new bacterial species. A dominant example of this is a coryneform bacterium isolated from over 90% of birds sampled. Antibiotic resistance was not detected in any of the penguin faecal isolates, in contrast to the bacteria isolated from the sewage outlets of Antarctic stations, indicating the birds have not been exposed to bacteria of human origin.