27Borrelia miyamotoi is an emerging tick-borne spirochete transmitted by Ixodid ticks.
28Current serologic assays for B. miyamotoi are impacted by genetic similarities to other 29 Borrelia and limited understanding of optimal antigenic targets. In this study, we 30 employed the TBD-Serochip, a peptide array platform, to identify new linear targets for 31 serologic detection of B. miyamotoi. We examined a wide range of suspected B.
32miyamotoi antigens and identified 352 IgM and 91 IgG reactive peptides, with the 33 majority mapping to variable membrane proteins. These included peptides within 34 conserved fragments of variable membrane proteins that may have greater potential for 35 differential diagnosis. We also identified reactive regions on FlaB, and demonstrate 36 crossreactivity of B. burgdorferi C6 with a B. miyamotoi C6-like peptide. The panel of 37 linear peptides identified in this study can be used to enhance serodiagnosis of B.38 miyamotoi. 39 40 41 42 43 44 45 46 47 48 49 50 51 52 miyamotoi was discovered in 1995; however, the link to disease was first established in 56 2011 when it was implicated in an outbreak of tick-borne illness in Russia (1, 6). B. 57 miyamotoi is primarily transmitted by I. scapularis and I. pacificus in North America, and 58 I. ricinus and I. persulcatus in Europe and Asia (6-9). These tick species also transmit 59 Borreliae that cause Lyme borreliosis (10). Lyme borreliosis is the most common vector-60 borne disease in the United States, where most infections are caused by Borrelia 61 burgdorferi and transmitted by Ixodes scapularis. Despite sharing the same vectors, B. 62 miyamotoi differs from B. burgdorferi in a number of ecological aspects, including the 63 ability for transovarial transmission, quicker transmission during tick feeding, and lower 64 infection rates in vector ticks. The prevalence of B. miyamotoi in nymphs is typically 1% 65 to 5% versus 15% to 25% for B. burgdorferi (11-15). Nonetheless, B. miyamotoi and B. 66 burgdorferi can occasionally infect the same tick, and concurrent human infections have 67 been reported (5, 15, 16). 68 69 Symptomatic infections with B. miyamotoi (Borrelia miyamotoi disease; BMD) usually 70 present with fever and other non-specific symptoms including fatigue, headache, chills 71 and nausea (17, 18). Bouts of relapsing fever may occur in untreated patients. In the 72 United States, reports of BMD are rare with less than 200 cases identified between 2011 73 and 2017 (3, 19, 20). This is considerably less than would be expected based on the 74 high incidence of other tick-borne diseases and suggests a substantial underreporting of 75 B. miyamotoi infections (21). A portion of infections may be asymptomatic while 76 symptomatic infections may not be identified because of a similar presentation to certain 77 other tick-borne illnesses and the lack of optimal diagnostic tests (22-24). Patients with 78 4 BMD may test positive on the C6 ELISA, a serologic assay used in the diagnosis of 79 Lyme disease (20, 25, 26). Current methods of BM...