that could not be adequately classified, nearly 332,000 sequences
remained with an average of3,200 sequences obtained for each
of the 102 palm surfaces swabbed (Table 1). For comparison, the
total number of sequences included in this study exceeds the
total number of sequences obtained from the largest previously
published molecular surveys of skin bacterial communities (6, 7)
by nearly 2 orders of magnitude. This dataset also provided the
most comprehensive survey of bacterial diversity in any humanassociated
habitat to date.
The average palm surface harbors 150 distinct species-level
bacterial phylotypes [a species is defined here as organisms
sharing 97% identity in their 16S rRNA gene sequences (13)]
(Table 1). Not surprisingly, this number of unique phylotypes
exceeds the number of bacterial types typically cultivated from