A Serological Survey of Borrelia burgdorferi Infection in Sheep in Northeast China Regions Through Outer Surface Protein C-Based Enzyme-Linked Immunosorbent Assay.

Borrelia burgdorferi as a causative agent of Lyme disease is transmitted by Ixodes spp. ticks to humans and animals. Sheep is considered a natural reservoir for B. burgdorferi and plays a pivotal role in disease transmission and the expansion of natural foci. An epidemiological investigation of B. burgdorferi in sheep is essential for prevention and control of Lyme disease. In this study, we developed a recombinant outer surface protein C (OspC)-based ELISA for serological study of B. burgdorferi in sheep with a specificity and sensitivity of 84.4% and 86.2%, respectively. A total of 972 collected serum samples from the Northeast China regions in 2015 and 2016 were determined with positive rates of 5.8% and 12.2%, respectively. Thus, specific pathogen-free sheep were infected with B. burgdorferi SZ strain to study on the secretion of specificity antibody against OspC. It revealed that specific antibody was detected on day 5 postinoculation and sustained in a high level for ∼28 days, the peak occurred at ∼13 days. Taken together, the result indicated that the established ELISA is capable for clinical diagnosis and epidemiological study on B. burgdorferi in sheep at the early stage of infection and detecting the specific antibody during the secretion period.