Chlamydia: more than meets the eye
A study involving the University of Southampton has shed new light on the genetic make-up of Chlamydia trachomatis and it’s relation to trachoma, the leading infectious cause of blindness.
The prevailing belief was that the chlamydial isolates that cause trachoma are a completely separate and ancient lineage from those that cause sexually transmitted infections (STIs), but this latest research, published in Nature Communications, has proven otherwise.
The study, a collaboration between scientists at the University of Southampton, Wellcome Trust Sanger Institute and Menzies School of Health at Charles Darwin University, Australia, conducted genome sequencing on Australian trachoma isolates.
The research re-examined a collection of eye swabs taken more than 30 years ago as part of a study of trachoma in children and their mothers from remote isolated Aboriginal communities in the Northern Territories, Australia.
Scientists found that just one or two gene variants can change an STI-causing-strain into a trachoma associated strain. Because it is also now known that chlamydia can readily exchange DNA this shows that there is a continued potential for new variant trachoma strains to emerge.
Ian Clarke, Professor of Virology at the University of Southampton, believes this is a major change in the understanding of Chlamydia.
He comments: “Australia is the only western country to still have trachoma, which was eradicated from the UK over 100 years ago. However, these results alert us that given the right conditions you never know when something might come back.
“Our research shows that preserving strains that cause disease is imperative to help tackle their potential re-emergence in the future.”
The trachoma samples were brought from Australia to the Chlamydia Biobank, a global resource centre for chlamydia research, based at the University of Southampton, by lead researcher Dr Pat Anderson. Together with Dr. Colette O’Neill and Mrs Lesley Cutcliffe they were able to resuscitate the chlamydia that had been frozen for 30 years.
The Chlamydia Biobank was launched last year and is the first dedicated collection of live Chlamydia trachomatis isolates, carefully selected to represent the full diversity of the species.
“The global Biobank will save these and other rare chlamydia from extinction as they might be useful for vaccine development in the future should new trachoma strains causing blindness emerge,” Professor Clarke adds.
“This was a brilliant collaboration that made best use of all the complementary skills from the three teams to address a difficult question on the evolution of chlamydia. It is just the kind of study the biobank was designed for.
“The outcome of this study demonstrates the huge value of long term storage of clinical and biological material, and its analysis with modern high technology.”
For more information about the Biobank visit http://www.chlamydiabiobank.co.uk/