Picture of two heads

Open Access research that challenges the mind...

The Strathprints institutional repository is a digital archive of University of Strathclyde research outputs. Strathprints provides access to thousands of Open Access research papers by University of Strathclyde researchers, including those from the School of Psychological Sciences & Health - but also papers by researchers based within the Faculties of Science, Engineering, Humanities & Social Sciences, and from the Strathclyde Business School.

Discover more...

Recombination and population structure in salmonella enterica

Didelot, Xavier and Bowden, Rory and Street, Teresa and Golubchik, Tanya and Spencer, Chris and McVean, Gil and Sangal, Vartul and Anjum, Muna and Achtman, Mark and Falush, Daniel and Donnelly, Peter (2011) Recombination and population structure in salmonella enterica. PLOS Genetics, 7 (7).

[img] PDF (Didelot_etal_PLoSGenetics2011)
Didelot_etal_PLoSGenetics2011.pdf - Final Published Version
License: Creative Commons Attribution 4.0 logo

Download (704kB)

Abstract

Salmonella enterica is a bacterial pathogen that causes enteric fever and gastroenteritis in humans and animals. Although its population structure was long described as clonal, based on high linkage disequilibrium between loci typed by enzyme electrophoresis, recent examination of gene sequences has revealed that recombination plays an important evolutionary role. We sequenced around 10% of the core genome of 114 isolates of enterica using a resequencing microarray. Application of two different analysis methods (Structure and ClonalFrame) to our genomic data allowed us to define five clear lineages within S. enterica subspecies enterica, one of which is five times older than the other four and two thirds of the age of the whole subspecies. We show that some of these lineages display more evidence of recombination than others. We also demonstrate that some level of sexual isolation exists between the lineages, so that recombination has occurred predominantly between members of the same lineage. This pattern of recombination is compatible with expectations from the previously described ecological structuring of the enterica population as well as mechanistic barriers to recombination observed in laboratory experiments. In spite of their relatively low level of genetic differentiation, these lineages might therefore represent incipient species.