Rickettsia gravesii sp. nov.: a novel spotted fever group rickettsia in Western Australian Amblyomma triguttatum triguttatum ticks by Abdad, M, Abdallah, R, Karkouri, K, Beye, M, Stenos, J, Owen, H, Unsworth, N, Robertson, I, Blacksell, S, Nguyen, T, Nappez, C, Raoult, D, Fenwick, S, Fournier, P