Mohammad Y. AbdadRita Abou AbdallahKhalid El KarkouriMamadou BeyeJohn StenosHelen OwenNathan UnsworthIan RobertsonStuart D. BlacksellThi Tien NguyenClaude NappezDidier RaoultStan FenwickPierre Edouard FournierMurdoch UniversityGeelong HospitalUnité de Recherche sur les Maladies Infectieuses et Tropicales émergentesLand DivisionMahidol UniversityUniversity of OxfordFaculte de Medecine de Marseille Universite de la Mediterranee2018-12-212019-03-142018-12-212019-03-142017-09-01International Journal of Systematic and Evolutionary Microbiology. Vol.67, No.9 (2017), 3156-3161146650262-s2.0-85029586186https://repository.li.mahidol.ac.th/handle/20.500.14594/41396© 2017 IUMS. A rickettsial organism harboured by Amblyomma triguttatum ticks on Barrow Island, Western Australia, was discovered after reports of possible rickettsiosis among local workers. Subsequent isolation of this rickettsia (strain BWI-1) in cell culture and analysis of its phylogenetic, genotypic and phenotypic relationships with type strains of Rickettsia species with standing in nomenclature suggested that it was sufficiently divergent to warrant its classification as a new species. Multiple gene comparison of strain BWI-1 revealed degrees of sequence similarity with Rickettsia raoultii, its closest relative, of 99.58, 98.89, 97.03, 96.93 and 95.73% for the 16S rRNA, citrate synthase, ompA, ompB and sca4 genes, respectively. Serotyping in mice also demonstrated that strain BWI-1Twas distinct from Rickettsia raoultii. Thus, we propose the naming of a new species, Rickettsia gravesii sp. nov., based on its novel genotypic and phenotypic characteristics. Strain BWI-1Twas deposited in the ATCC, CSUR and ARRL collections under reference numbers VR-1664, CSUR R172 and RGBWI-1, respectively.Mahidol UniversityAgricultural and Biological SciencesImmunology and MicrobiologyArticleSCOPUS10.1099/ijsem.0.001865