Phylogenetically distinct Staphylococcus aureus lineage prevalent among indigenous communities in northern Australia

Abstract

The aim was to determine the evolutionary position of the Staphylococcus aureus clonal complex 75 (CC75) that is prevalent in tropical northern Australia. Sequencing of gap, rpoB, sodA, tuf, and hsp60 and the multilocus sequence typing loci revealed a clear separation between conventional S. aureus and CC75 and significant diversity within CC75.

FIG. 1.

Neighbor-joining trees of gap, rpoB, sodA, tuf, and hsp60 DNA sequences. The DNA sequences from S. aureus strains, CC75 isolates, and different Staphylococcus species were used. The following fragments of the coding sequences were used: fragment from position 58 to 941 for gap, fragment from position 1 to 492 for rpoB, fragment from position 11 to 380 for sodA, fragment from position 1 to 538 for hsp60, and fragment from position 360 to 730 for tuf (conventional S. aureus numbering). Scale bars and numbers represent the number of nucleotide differences.

FIG. 2.

Neighbor-joining tree of representative yqiL alleles from the S. aureus MLST database. To aid presentation, only a subset of alleles were included. The alleles were selected to encompass as much diversity as possible. Scale bars and numbers represent the number of nucleotide differences.