Repetitive Strain

With symptoms including fevers and rashes, scrub typhus is a disease estimated to affect a million people annually, mostly in Asia, and is caused by the bacterium Orientia tsutsugamushi. Transmitted by the bites of mite larvae, known as chiggers, O. tsutsugamushi is an obligate intracellular pathogen, meaning that it must be inside a host cell to survive. Compared to other closely-related bacteria with a similar lifestyle, it has a large genome, featuring many repeated sequences of DNA. These repeats are represented in this diagram: along the genome, pictured as a grey circle, each coloured bar indicates a region of DNA with multiple copies, linked together to show where the repeats are found. Piecing together a genome with so many repeats is challenging, but new sequencing techniques recently enabled more accurate reconstructions of genomes from multiple O. tsutsugamushi strains, providing more detailed insights into an important yet relatively poorly-understood pathogen.

Written by Emmanuelle Briolat

Emmanuelle Briolat

Writer

A researcher specialising in visual signals in Lepidoptera, camouflage and the effects of light pollution, Emmanuelle’s writing covers a range of topics, from biomedical research to children’s books about moth defences.

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• Image by Elizabeth Batty, created using Sibelia (http://bioinf.spbau.ru/sibelia) and Circos (http://circos.ca/ )
• Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand, Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
• Originally published under a Creative Commons Licence (BY 4.0)
• Published in PLOS Neglected Tropical Diseases, June 2018