Format

Send to

Choose Destination
PLoS One. 2015 Mar 16;10(3):e0118613. doi: 10.1371/journal.pone.0118613. eCollection 2015.

Molecular phylogenetic analysis of non-sexually transmitted strains of Haemophilus ducreyi.

Author information

1
Department of Biology, Allegheny College, Meadville, Pennsylvania, United States of America.
2
Department of Microbiology, Auckland District Health Board, Auckland, New Zealand.

Abstract

Haemophilus ducreyi, the etiologic agent of chancroid, has been previously reported to show genetic variance in several key virulence factors, placing strains of the bacterium into two genetically distinct classes. Recent studies done in yaws-endemic areas of the South Pacific have shown that H. ducreyi is also a major cause of cutaneous limb ulcers (CLU) that are not sexually transmitted. To genetically assess CLU strains relative to the previously described class I, class II phylogenetic hierarchy, we examined nucleotide sequence diversity at 11 H. ducreyi loci, including virulence and housekeeping genes, which encompass approximately 1% of the H. ducreyi genome. Sequences for all 11 loci indicated that strains collected from leg ulcers exhibit DNA sequences homologous to class I strains of H. ducreyi. However, sequences for 3 loci, including a hemoglobin receptor (hgbA), serum resistance protein (dsrA), and a collagen adhesin (ncaA) contained informative amounts of variation. Phylogenetic analyses suggest that these non-sexually transmitted strains of H. ducreyi comprise a sub-clonal population within class I strains of H. ducreyi. Molecular dating suggests that CLU strains are the most recently developed, having diverged approximately 0.355 million years ago, fourteen times more recently than the class I/class II divergence. The CLU strains' divergence falls after the divergence of humans from chimpanzees, making it the first known H. ducreyi divergence event directly influenced by the selective pressures accompanying human hosts.

PMID:
25774793
PMCID:
PMC4361675
DOI:
10.1371/journal.pone.0118613
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Public Library of Science Icon for PubMed Central
Loading ...
Support Center