Candidatus Bartonella antechini: a novel Bartonella species detected in fleas and ticks from the yellow-footed antechinus (Antechinus flavipes), an Australian marsupial

Bartonella are fastidious, Gram-negative, aerobic bacilli belonging to the Alphaproteobacteria group. In the last ten years, the discovery of new Bartonella species from a variety of mammalian hosts, arthropod vectors and geographical areas has increased. More than 20 species of Bartonella have been identified, of which approximately thirteen are associated with disease in humans and animals. Recently, four novel species of Bartonella were isolated from mammalian hosts in Australia: Bartonella australis from eastern grey kangaroos (Macropus giganteus) and Bartonella rattaustraliani, Bartonella queenslandensis and Bartonella coopersplainsensis from rodents. Bartonella-like organisms have also been detected from Ixodes tasmani ticks collected from koalas (Phascolarctos cinereus). However, very little is known about Bartonella spp. in other marsupials in Australia. We report the identification of a novel Bartonella species detected from fleas (Acanthopsylla jordani) and ticks (Ixodes antechini) collected from a small carnivorous marsupial, Antechinus flavipes (Mardos or Yellow-footed antechinus) in the southwest of Western Australia. New nested-PCRs targeting the gltA gene and the ribosomal ITS region were developed as part of the present study. DNA sequencing of the 16S rRNA, gltA, ftsZ and rpoB genes and the ribosomal ITS region revealed that this detection is a distinct Bartonella species and is related to B. australis isolated from kangaroos. This is the first report of two different possible arthropod vectors in Australia (ticks and fleas) being infected with the same species of Bartonella. We propose the name Candidatus Bartonella antechini n. sp. for the recently characterized organism.