Figure 2.

Western blot analysis using the Orientia spp.–specific antigen (Otr47b). Twenty scrub typhus reactive serum samples at a titer ≥1:6,000 were used. Negative controls were serum samples that were reactive to spotted fever and typhus group antigens. The scrub typhus reactive serum samples recognized the Otr47b antigen (lanes 2 and 3), but the spotted fever group and typhus group reactive serum samples did not (data not shown). Lane 1 was probed with a positive control serum sample from an earlier scrub typhus outbreak study (5). M, molecular mass standard, kDa.