DEFORMATION FACTOR - AN EXTRACELLULAR PROTEIN SYNTHESIZED BY BARTONELLA-BACILLIFORMIS THAT DEFORMS ERYTHROCYTE-MEMBRANES

Bartonella bacilliformis, a hemotropic bacterium and the causative agent of the human disease bartonellosis, when incubated in a tryptone-based medium produces an extracellular factor, termed deformation factor (DF), which induces extensive indentations and trenches in trypsinized erythrocyte membranes. The factor is stable during storage at 4-degrees-C. It can be inactivated by proteases or brief heating to 70 to 80-degrees-C, can be precipitated by ammonium sulfate, is nondialyzable, and is retained by membranes with a 30,000-molecular-weight cutoff. These properties suggest that DF is probably a protein. Incubation of erythrocytes with phospholipase D renders them resistant to deformation by DF.