A random six-phase switch regulates pneumococcal virulence via global epigenetic changes.
journal contributionposted on 2016-12-16, 14:41 authored by Ana Sousa Manso, M. H. Chai, J. M. Atack, Leonardo Furi, Megan De Ste Croix, Richard Haigh, C. Trappetti, A. D. Ogunniyi, L. K. Shewell, M. Boitano, T. A. Clark, J. Korlach, Matthew Blades, Evgeny Mirkes, Alexander N. Gorban, J. C. Paton, M. P. Jennings, Marco R. Oggioni
Streptococcus pneumoniae (the pneumococcus) is the world's foremost bacterial pathogen in both morbidity and mortality. Switching between phenotypic forms (or 'phases') that favour asymptomatic carriage or invasive disease was first reported in 1933. Here, we show that the underlying mechanism for such phase variation consists of genetic rearrangements in a Type I restriction-modification system (SpnD39III). The rearrangements generate six alternative specificities with distinct methylation patterns, as defined by single-molecule, real-time (SMRT) methylomics. The SpnD39III variants have distinct gene expression profiles. We demonstrate distinct virulence in experimental infection and in vivo selection for switching between SpnD39III variants. SpnD39III is ubiquitous in pneumococci, indicating an essential role in its biology. Future studies must recognize the potential for switching between these heretofore undetectable, differentiated pneumococcal subpopulations in vitro and in vivo. Similar systems exist in other bacterial genera, indicating the potential for broad exploitation of epigenetic gene regulation.
This work was supported by The FP7 Marie Curie ITN 238490 and PNEUMOPATH 222983 (to M.R.O.), Program Grant 565526 from the National Health and Medical Research Council of Australia (NHMRC) (to J.C.P. and M.P.J.) and NHMRC Project Grants 627142 (to J.C.P. and A.D.O.) and 1034401 (to M.P.J.); J.C.P. is a NHMRC Senior Principal Research Fellow, C.T. is an Australian Research Council DECRA Fellow. The data mining part was in part supported by the Wellcome Trust Institutional Strategic Support Fund WT097828/Z/11/Z (RM33G0255 and RM33G0335).
CitationNature Communications, 2014, 5:5055
Author affiliation/Organisation/COLLEGE OF MEDICINE, BIOLOGICAL SCIENCES AND PSYCHOLOGY/MBSP Non-Medical Departments/Department of Genetics
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