Dissemination and survival of non-indigenous bacterial genomes in pristine Antarctic environments.

Continental Antarctic is perceived as a largely pristine environment, although certain localized regions (e.g., parts of the Ross Dependency Dry Valleys) are relatively heavy impacted by human activities. The procedures imposed on Antarctic field parties for the handling and disposal of both solid and liquid wastes are designed to minimise eutrofication and contamination (particularly by human enteric bacteria). However, little consideration has been given to the significance, if any, of less obvious forms of microbial contamination resulting from periodic human activities in Antarctica. The predominant commensal microorganism on human skin, Staphylococcus epidermidis, could be detected by PCR, in Dry Valley mineral soils collected from heavily impacted areas, but could not be detected in Dry Valley mineral soils collected from low impact and pristine areas. Cell viability of this non-enteric human commensal is rapidly lost in Dry Valley mineral soil. However, S. epidermidis can persist for long periods in Dry Valley mineral soil as non-viable cells and/or naked DNA

Non-specificity of Staphylococcus generic primers

Published as a "Microbiology Comment": this provides a platform for readers of Microbiology to communicate their personal observations and opinions in a more informal way than through the submission of papers.Our results allow us to conclude that there appears to be significant conservation between the tuf genes of Planococcus, Planomicrobium and Staphylococcus spp., and that although the primer set TstaG422/TStag765 has been shown to possess high specificity, its use for the definitive identification of Staphylococcus spp. must be treated with some caution

PCR-based detection of non-indigenous microorganisms in ‘pristine’ environments

PCR-based technologies are widely employed for the detection of specific microorganisms, and may be applied to the identification of non-indigenous microorganisms in ‘pristine’ environments. For ‘pristine’ environments such as those found on the Antarctic continent, the application of these methods to the assessment of environmental contamination from human activities must be treated with caution. Issues such as the possibility of non-human dispersal of organisms, stability and survival of non-indigenous organisms in vivo, the sensitivity, reproducibility and specificity of the PCR process (and particularly primer design) and the sampling regime employed must all be considered in detail. We conclude that despite these limitations, PCR and related technologies offer enormous scope for assessment of both natural and non-indigenous microbial distributions