Bartonella-Like DNA Detected in Ixodes tasmani Ticks (Acari: Ixodida) Infesting Koalas (Phascolarctos cinereus) in Victoria, Australia

A total of 42 ticks comprising Ixodes tasmani (n = 41) and Ixodes trichosuri (n = 1) were collected from wild koalas (Phascolarctos cinereus) at the Koala Convention Centre, Philip Island, Victoria, Australia and screened for the presence of Bartonella using the target gene gltA. Bartonella-like DNA was detected in 4 of the 19 pooled tick samples (21%). All positive ticks were male. Analysis of partial sequences for the gltA gene indicated the presence of a Bartonella-related species similar to that reported in another Ixodid species. This is the first report of Bartonella-like organisms in a native Australian marsupial.