Summary
Penguins breeding in the Antarctic have evolved in the most isolated ecosystem in the world. However, recent increase in human activity in the region, both in tourism and science, has led to concern regarding the possible introduction of infectious agents to Antarctic wildlife. While much research has been carried out into the breeding biology 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. To obtain such information and assess possible sources of introduction of infection, we have collected faecal and blood samples from over 1000 Adelie (Pygoscelis adeliae) and Emperor (Aptenodytes forsteri) penguins and 125 migratory South Polar Skuas (Catharacta maccormicki) from various locations in Antarctica, both close to and remote from expedition stations. Samples have also been collected from station sewage outlets. While no serum antibodies to Newcastle Disease virus (NDV) or Avian Influenza virus (AI) have been detected in penguins 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 (IBDV). These results suggest this virus is widespread in Antarctic penguin populations. Interestingly, 19.3% of skuas were found to be seropositive to IBDV, 10% to NDV and 1% to AI, indicating these migratory birds are likely candidates for introduction of disease to which the Antarctic wildlife have not previously been exposed. Bacterial analysis has revealed the presence of aerobic and anaerobic bacteria in all penguin faecal samples, including a number of apparently new bacterial species. No antibiotic resistance was detected in penguin faecal coliforms though bacteria isolated from the sewage outlets of Antarctic stations display high levels of resistance, indicating penguins have not been exposed to bacteria of human origin.