Figure 4. Schematic representation of the presence of OspC on Borrelia burgdorferi and variable small protein (Vsp) 33 on B. hermsii during infection in their respective tick vectors. Shown is the proportion of spirochetes detected with double-label immunofluorescence stains that includes either anti-outer surface protein C (Osp C) antibody (top) or anti-Vsp33 antibody (bottom). B. burgdorferi produces OspC in the midgut of Ixodes scapularis for only a few days, starting after these ticks have attached and begun to feed. During the 3 to 5 days of tick feeding, these spirochetes replicate, disseminate from the midgut, and are transmitted via saliva. In contrast, B. hermsii gradually upregulates the synthesis of Vsp33 after infecting Ornithodoros hermsi, and essentially all the spirochetes express the protein during persistent infection of the tick salivary glands.
The opinions expressed by authors contributing to this journal do not necessarily reflect the opinions of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.