Bartonella bacilliformis: colonial types and erythrocyte adherence

Bartonella bacilliformis was cultivated on a solid medium, and two bartonella colonial morphologies were differentiated and designated colony types T1 and T2. Although both T1 and T2 bartonellae adhered to human erythrocytes in vitro, approximately twice as many T2 bartonellae adhered as did T1. Maximum adherence required bartonella energy, most likely proton motive force-dependent motility. Bartonellae did not penetrate or lyse erythrocytes in vitro. Bartonellae adhered poorly to alpha- or beta-glucosidase-treated erythrocytes, but pronase or subtilisin treatment of erythrocytes stimulated adherence. This indicates that bartonellae probably adhere to an erythrocyte glycolipid moiety.