Whole-Genome Sequencing of Chlamydia trachomatis Directly from Human Samples

Abstract

Whole-genome sequencing is a powerful, high-resolution tool that can be used to generate accurate data on bacterial population structure, phylogeography and mutations associated with antimicrobial resistance. The ability to sequence pathogen genomes directly from clinical specimens, without the requirement for in vitro culturing, is attractive in terms of time- and labor-saving, especially in the case of slow growing, or obligate intracellular pathogens, such as Chlamydia trachomatis. However clinical samples typically contain too low levels of pathogen nucleic acid, plus relatively high levels of human and natural microbiota DNA/RNA, to make this a viable option. Using a combination of whole-genome enrichment and deep sequencing, which has been proven to be a nonmutagenic approach, we can capture all known variation found within C. trachomatis genomes. The method is a consistent and sensitive tool that enables rapid whole-genome sequencing of C. trachomatis directly from clinical samples and has the potential to be adapted to other pathogens with a similar clonal nature.