Analysis of soil samples for human comensal micro-organism to determine the degree of human induced microbial contamination of heavily used regions

Mineral soils from the immediate vicinity of field campsites in the Wright Valley, Miers Valley and Bratina Island campsites were sampled daily during occupation. The samples were analysed with PCR based methods using a range of genus- and species-specific DNA primers to detect human commensal microbiota. The aim was to monitor the rate and degree of contamination of heavily impacted regions by human activities. Pristine samples were recovered from relatively inaccessible sites high on the eastern wall of the valleys. Ornithogenic soils were sampled from various sites in the Adele penguin colony at Cape Crozier for comparative microbial diversity studies as these samples could be valuable negative controls for the 'non-indigenous' microorganisms study, for confirming that positive signals with particular sets are not the result of cross-reactivity with microbial species that are carried by higher eukaryotes other than humans. Samples of gravel were also collected from heavily impacted sites at Scott Base and McMurdo station as these samples serve as positive controls for the non-indigenous microorganisms. An additional sample was obtained from a Scott Base vaccum cleaner. Gravel samples were also collected from the doorway entrance to Shackleton's Hut at Cape Royds and Scotts Hut at Hut Point.