Patimaporn WongprompitakVeasna DuongWichittra AnukoolLay SreyrathTrinh Thi Xuan MaiLaurent GavotteCatherine MouliaEmmanuel CornillotPattama EkpoYupin SuputtamongkolPhilippe BuchyRoger FrutosMahidol UniversityInstitut des Sciences de l'Evolution UMR 5554Institut Pasteur du CambodgeNha Trang Pasteur InstituteCNRS Centre National de la Recherche ScientifiqueCIRAD Centre de Recherche de Montpellier2018-11-232018-11-232015-04-01Infection, Genetics and Evolution. Vol.31, (2015), 1-815677257156713482-s2.0-84921408099https://repository.li.mahidol.ac.th/handle/20.500.14594/35180© 2015 Elsevier B.V. Orientia tsutsugamushi is the causative agent of scrub typhus, a major cause of febrile illness in rural area of Asia-Pacific region. A multi-locus sequence typing (MLST) analysis was performed on strains isolated from human patients from 3 countries in Southeast Asia: Cambodia, Vietnam and Thailand. The phylogeny of the 56-kDa protein encoding gene was analyzed on the same strains and showed a structured topology with genetically distinct clusters. MLST analysis did not lead to the same conclusion. DNA polymorphism and phylogeny of individual gene loci indicated a significant level of recombination and genetic diversity whereas the ST distribution indicated the presence of isolated patches. No correlation was found with the geographic origin. This work suggests that weak divergence in core genome and ancestral haplotypes are maintained by permanent recombination in mites while the 56-kDa protein gene is diverging in higher speed due to selection by the mammalian immune system.Mahidol UniversityAgricultural and Biological SciencesBiochemistry, Genetics and Molecular BiologyImmunology and MicrobiologyMedicineArticleSCOPUS10.1016/j.meegid.2015.01.005