Isolation of a new subspecies, Bartonella vinsonii subsp arupensis, from acattle rancher: Identity with isolates found in conjunction with Borrelia burgdorferi and Babesia microti among naturally infected mice

Bacteremia with fever due to a novel subspecies of Bartonella vinsonii was found in a cattle rancher. The subspecies shared major characteristics of t he genus Bartonella in terms of most biochemical features and cellular fatt y acid profile, but it was distinguishable from other subspecies of B. vins onii by good growth on heart infusion agar supplemented with X factor and b y its pattern of enzymatic hydrolysis of peptide substrates. DNA relatednes s studies verified that the isolate belonged to the genus Bartonella and th at it was genotypically related to B. vinsonii. The highest level of relate dness was observed with recently characterized strains from naturally infec ted mice that were coinfected with Borrelia burgdorferi and Babesia microti . We propose the name Bartonella vinsonii subsp. arupensis subsp. nov. as t he new subspecies to accommodate these human and murine isolates.