{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"bioRxiv"}],"indexed":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T07:52:01Z","timestamp":1785916321653,"version":"3.56.0"},"posted":{"date-parts":[[2026,7,31]]},"group-title":"Microbiology","reference-count":52,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,7,31]],"date-time":"2026-07-31T00:00:00Z","timestamp":1785456000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000060","name":"National Institute of Allergy and Infectious Diseases","doi-asserted-by":"crossref","award":["AI191624"],"award-info":[{"award-number":["AI191624"]}],"id":[{"id":"10.13039\/100000060","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/100000060","name":"National Institute of Allergy and Infectious Diseases","doi-asserted-by":"crossref","award":["AI197410"],"award-info":[{"award-number":["AI197410"]}],"id":[{"id":"10.13039\/100000060","id-type":"DOI","asserted-by":"crossref"}]},{"id":[{"id":"https:\/\/ror.org\/032sf2845","id-type":"ROR","asserted-by":"publisher"}]},{"name":"Texas EcoLabs"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,8,3]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:p>\n                  Tick-borne relapsing fever (TBRF) spirochetes are maintained in nature through vector-associated transmission routes primarily in argasid ticks. However, the extent to which strain-level differences influence the maintenance of TBRF spirochetes remains unclear. We evaluated two\n                  <jats:italic>Borrelia turicatae<\/jats:italic>\n                  strains,\n                  <jats:italic>Bt<\/jats:italic>\n                  \u2013SSK1 and\n                  <jats:italic>Bt<\/jats:italic>\n                  \u2013FCB, in\n                  <jats:italic>Ornithodoros turicata<\/jats:italic>\n                  . Both strains were acquired by female ticks, and after mating we unexpectedly observed that they were hyperparasitized by uninfected and unfed male\n                  <jats:italic>O. turicata. Bt<\/jats:italic>\n                  \u2013 SSK1 was maintained in males while\n                  <jats:italic>Bt\u2013<\/jats:italic>\n                  FCB was not. Transovarial transmission (TOT) of\n                  <jats:italic>Bt<\/jats:italic>\n                  \u2013SSK1 and\n                  <jats:italic>Bt<\/jats:italic>\n                  \u2013FCB was also evaluated and striking differences were observed between strains.\n                  <jats:italic>Bt<\/jats:italic>\n                  \u2013SSK1 was vertically maintained in F1 progeny but we failed to detect TOT of\n                  <jats:italic>Bt<\/jats:italic>\n                  \u2013FCB. TOT of\n                  <jats:italic>Bt<\/jats:italic>\n                  \u2013SSK1 occurred inefficiently in early ovipositions but increasing in later or delayed reproductive events, indicating a timing-dependent barrier. Using a\n                  <jats:italic>gfp<\/jats:italic>\n                  \u2013expressing\n                  <jats:italic>Bt<\/jats:italic>\n                  \u2013FCB strain, we show that failure of vertical transmission is associated with a lack of persistent oocyte colonization despite dissemination to ovarian tissues. These findings demonstrate strain-dependent differences in oocyte colonization and represent a critical bottleneck governing vertical transmission and persistence of relapsing fever spirochetes in tick populations.\n                <\/jats:p>\n                <jats:sec>\n                  <jats:title>Importance<\/jats:title>\n                  <jats:p>\n                    Vector-borne pathogens rely on diverse transmission strategies to persist in nature, yet the biological factors that govern these processes remain poorly understood. In this study, we demonstrated that strains of\n                    <jats:italic>Borrelia turicatae<\/jats:italic>\n                    differ markedly in their ability to persist within\n                    <jats:italic>Ornithodoros turicata<\/jats:italic>\n                    ticks. We also discovered that male ticks frequently hyperparasitized engorged females, creating an unrecognized transmission route in which previously uninfected ticks can acquire, maintain, and transmitted the\n                    <jats:italic>B. turicatae<\/jats:italic>\n                    . We further showed phenotypic differences in vertical transmission and that it is temporally regulated and linked to successful colonization of developing oocytes, identifying a critical bottleneck in pathogen maintenance. Together, these findings revealed that strain-specific traits influence both horizontal maintenance within tick populations and vertical transmission to progeny. This work provides insight into the ecological and evolutionary processes that enable relapsing fever spirochetes to persist in nature.\n                  <\/jats:p>\n                <\/jats:sec>","DOI":"10.64898\/2026.07.30.741854","type":"posted-content","created":{"date-parts":[[2026,8,1]],"date-time":"2026-08-01T05:40:16Z","timestamp":1785562816000},"source":"Crossref","is-referenced-by-count":0,"title":["Defining strain variation in the maintenance of\n                  <i>Borrelia turicatae<\/i>\n                  during hyperparasitism and transovarial transmission in the tick vector"],"prefix":"10.64898","author":[{"given":"Serhii","family":"Filatov","sequence":"first","affiliation":[{"name":"Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, U.S.A"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michael W.","family":"Curtis","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, U.S.A"},{"name":"Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, U.S.A"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alexander R.","family":"Kneubehl","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, U.S.A"},{"name":"Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, U.S.A"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Winnie W.","family":"Kamau","sequence":"additional","affiliation":[{"name":"Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, U.S.A"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Victor F.","family":"Figueroa","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, U.S.A"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Brandon A.","family":"Hogland","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jon S.","family":"Blevins","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Job E.","family":"Lopez","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, U.S.A"},{"name":"Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, U.S.A"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"54368","reference":[{"key":"2026080500400457000_2026.07.30.741854v2.1","first-page":"97","article-title":"Evolutionary Genetics of Borrelia","volume":"42","year":"2021","journal-title":"Curr Issues Mol Biol"},{"key":"2026080500400457000_2026.07.30.741854v2.2","doi-asserted-by":"crossref","first-page":"e442","DOI":"10.1016\/S2666-5247(23)00396-8","article-title":"The global distribution and the risk prediction of relapsing fever group Borrelia: a data review with modelling analysis","volume":"5","year":"2024","journal-title":"Lancet Microbe"},{"key":"2026080500400457000_2026.07.30.741854v2.3","unstructured":"Felsenfeld O . 1971. Borrelia. Strains, vectors, human and animal borreliosis. WH Green, St. Louis."},{"key":"2026080500400457000_2026.07.30.741854v2.4","doi-asserted-by":"crossref","unstructured":"Talagrand-Reboul E , Boyer PH , Bergstr\u00f6m S , Vial L , Boulanger N . 2018. Relapsing Fevers: Neglected Tick-Borne Diseases. Front Cell Infect Microbiol 8.","DOI":"10.3389\/fcimb.2018.00098"},{"key":"2026080500400457000_2026.07.30.741854v2.5","doi-asserted-by":"crossref","first-page":"278","DOI":"10.1089\/vbz.2023.0090","article-title":"Borrelia nietonii sp. nov.: relapsing fever spirochetes transmitted by the tick Ornithodoros hermsi designated previously as Borrelia hermsii genomic group II","volume":"24","year":"2024","journal-title":"Vector-Borne Zoonotic Dis"},{"key":"2026080500400457000_2026.07.30.741854v2.6","doi-asserted-by":"crossref","first-page":"1926","DOI":"10.1093\/jme\/tjab060","article-title":"Vector specificity of the relapsing fever spirochete Borrelia hermsii (Spirochaetales: Borreliaceae) for the tick Ornithodoros hermsi (Acari: Argasidae) involves persistent infection of the salivary glands","volume":"58","year":"2021","journal-title":"J Med Entomol"},{"key":"2026080500400457000_2026.07.30.741854v2.7","first-page":"1","article-title":"Tick-borne relapsing fever spirochetes in the Americas","volume":"3","year":"2016","journal-title":"Vet Sci"},{"key":"2026080500400457000_2026.07.30.741854v2.8","first-page":"161","article-title":"Bloodsucking ticks (Ixodoidea)-vectors of diseases of man and animals","volume":"8","year":"1972","journal-title":"Misc Publ Entomol Soc Am"},{"key":"2026080500400457000_2026.07.30.741854v2.9","doi-asserted-by":"crossref","first-page":"334","DOI":"10.1016\/j.ttbdis.2017.11.009","article-title":"Conspecific hyperparasitism: An alternative route for Borrelia hermsii transmission by the tick Ornithodoros hermsi","volume":"9","year":"2018","journal-title":"Ticks Tick Borne Dis"},{"key":"2026080500400457000_2026.07.30.741854v2.10","doi-asserted-by":"crossref","first-page":"64","DOI":"10.31857\/S003118472401006X","article-title":"The phenomenon of attachment and feeding of unfed ticks (Ixodoidea) on fed and feeding specimens of the same or different species: biological and epidemiological issues","volume":"58","year":"2024","journal-title":"Parazitologiya"},{"key":"2026080500400457000_2026.07.30.741854v2.11","doi-asserted-by":"crossref","unstructured":"Jorge FR , de Oliveira GMB , Silito IS , Martins MP , Munoz-Leal S , Labruna MB . 2026. Transstadial and transovarial perpetuations of Borrelia venezuelensis in Ornithodoros rudis, with demonstration of vector competence. Exp Appl Acarol 96.","DOI":"10.1007\/s10493-026-01124-z"},{"key":"2026080500400457000_2026.07.30.741854v2.12","unstructured":"Barbour AG , Schwan TG . 2018. Borrelia. John Wiley & Sons, Inc. in association with Bergey\u2019s Manual Trust."},{"key":"2026080500400457000_2026.07.30.741854v2.13","doi-asserted-by":"crossref","first-page":"839","DOI":"10.2307\/4584474","article-title":"Relapsing fever: The tick Ornithodoros turicata as a spirochetal reservoir","volume":"58","year":"1943","journal-title":"Public Health Rep"},{"key":"2026080500400457000_2026.07.30.741854v2.14","doi-asserted-by":"publisher","DOI":"10.1128\/aem.01032-23:e0103223"},{"key":"2026080500400457000_2026.07.30.741854v2.15","doi-asserted-by":"crossref","unstructured":"Krishnavajhala A , Armstrong BA , Lopez JE . 2018. Vector competence of geographical populations of Ornithodoros turicata for the tick-borne relapsing fever spirochete Borrelia turicatae . Appl Environ Microbiol 84.","DOI":"10.1128\/AEM.01505-18"},{"key":"2026080500400457000_2026.07.30.741854v2.16","doi-asserted-by":"publisher","DOI":"10.1093\/jmedent\/23.3.313"},{"key":"2026080500400457000_2026.07.30.741854v2.17","doi-asserted-by":"crossref","first-page":"369","DOI":"10.1007\/BF00130549","article-title":"Reproductive bionomics of the soft tick, Ornithodoros turicata (Acari: Argasidae)","volume":"20","year":"1996","journal-title":"Exp Appl Acarol"},{"key":"2026080500400457000_2026.07.30.741854v2.18","doi-asserted-by":"crossref","first-page":"e0012348","DOI":"10.1371\/journal.pntd.0012348","article-title":"Development and validation of systems for genetic manipulation of the Old World tick-borne relapsing fever spirochete, Borrelia duttonii","volume":"18","year":"2024","journal-title":"PLoS Negl Trop Dis"},{"key":"2026080500400457000_2026.07.30.741854v2.19","doi-asserted-by":"publisher","DOI":"10.2307\/4582740"},{"key":"2026080500400457000_2026.07.30.741854v2.20","doi-asserted-by":"publisher","DOI":"10.1017\/S0031182000054676"},{"key":"2026080500400457000_2026.07.30.741854v2.21","first-page":"21","article-title":"Effect of extrinsic incubation temperature on transstadial and transovarial transmission of Borrelia sp. in Ornithodoros (O.) savignyi and infectivity to vertebrate host","volume":"1","year":"2009","journal-title":"Egypt Acad J Biol Sci E Med Entomol Parasitol"},{"key":"2026080500400457000_2026.07.30.741854v2.22","doi-asserted-by":"publisher","DOI":"10.1093\/gbe\/evz243"},{"key":"2026080500400457000_2026.07.30.741854v2.23","doi-asserted-by":"crossref","first-page":"463","DOI":"10.1007\/s10682-009-9319-z","article-title":"Life cycle and population dynamics of a protective insect symbiont reveal severe bottlenecks during vertical transmission","volume":"24","year":"2010","journal-title":"Evol Ecol"},{"key":"2026080500400457000_2026.07.30.741854v2.24","doi-asserted-by":"crossref","first-page":"279","DOI":"10.2307\/3281876","article-title":"Effects of temperature and tick weight on expression of autogeny in the argasid tick Ornithodoros parkeri Cooley (acari: Argasidae)","volume":"70","year":"1984","journal-title":"J Parasitol"},{"key":"2026080500400457000_2026.07.30.741854v2.25","doi-asserted-by":"crossref","unstructured":"Abdel Hamid AE , Mohmad AY , Shanbaky NM , Helmy N , Soliman DE , Khater HM , Ahmed SS . 2025. Biological and histological studies on tick-Borrelia interaction during reproduction and transovarial transmission of B. crocidurae in female Ornithodoros erraticus . Egypt J Vet Sci:1\u201310.","DOI":"10.21608\/ejvs.2024.334411.2479"},{"key":"2026080500400457000_2026.07.30.741854v2.26","doi-asserted-by":"crossref","first-page":"102052","DOI":"10.1016\/j.ttbdis.2022.102052","article-title":"Characterization of the arthropod associated lipoprotein (Alp) in the tick-mammalian transmission cycle of Borrelia turicatae","volume":"13","year":"2022","journal-title":"Ticks Tick Borne Dis"},{"key":"2026080500400457000_2026.07.30.741854v2.27","doi-asserted-by":"crossref","unstructured":"Jackson-Litteken CD , Ratliff CT , Kneubehl AR , Siletti C , Pack L , Lan R , Huynh TN , Lopez JE , Blevins JS . 2021. The Diadenylate Cyclase CdaA Is Critical for Borrelia turicatae Virulence and Physiology. Infect Immun 89.","DOI":"10.1128\/IAI.00787-20"},{"key":"2026080500400457000_2026.07.30.741854v2.28","doi-asserted-by":"crossref","first-page":"290","DOI":"10.3389\/fcimb.2019.00290","article-title":"Assessing the contribution of an HtrA family serine protease during Borrelia turicatae mammalian infection","volume":"9","year":"2019","journal-title":"Front Cell Infect Microbiol"},{"key":"2026080500400457000_2026.07.30.741854v2.29","doi-asserted-by":"crossref","unstructured":"Krishnavajhala A , Wilder HK , Boyle WK , Damania A , Thornton JA , Perez de Leon AA , Teel PD , Lopez JE . 2017. Imaging of Borrelia turicatae producing the green fluorescent protein reveals persistent colonization of the Ornithodoros turicata midgut and salivary glands from nymphal acquisition through transmission. Appl Environ Microbiol 83.","DOI":"10.1128\/AEM.02503-16"},{"key":"2026080500400457000_2026.07.30.741854v2.30","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pntd.0002514"},{"key":"2026080500400457000_2026.07.30.741854v2.31","doi-asserted-by":"publisher","DOI":"10.1111\/1462-2920.12455"},{"key":"2026080500400457000_2026.07.30.741854v2.32","doi-asserted-by":"crossref","first-page":"1174","DOI":"10.1007\/s11427-020-1801-7","article-title":"New insights into the transovarial transmission of the symbiont Rickettsia in whiteflies","volume":"64","year":"2021","journal-title":"Sci China Life Sci"},{"key":"2026080500400457000_2026.07.30.741854v2.33","doi-asserted-by":"crossref","first-page":"1978","DOI":"10.3390\/microorganisms9091978","article-title":"Transovarial transmission of Borrelia hermsii by its tick vector and reservoir host Ornithodoros hermsi","volume":"9","year":"2021","journal-title":"Microorganisms"},{"key":"2026080500400457000_2026.07.30.741854v2.34","doi-asserted-by":"crossref","first-page":"607","DOI":"10.1089\/vbz.2007.0279","article-title":"Absence of transovarial transmission of Borrelia duttonii, a tick-borne relapsing fever agent, by the vector tick Ornithodoros moubata","volume":"8","year":"2008","journal-title":"Vector-Borne Zoonotic Dis"},{"key":"2026080500400457000_2026.07.30.741854v2.35","doi-asserted-by":"crossref","unstructured":"Wheeler CM . 1938. Progress of spirochaete infection in the developmental stages of the host tick, Ornithodoros hermsi, Wheeler. Am J Trop Med s1-18:413-419.","DOI":"10.4269\/ajtmh.1938.s1-18.413"},{"key":"2026080500400457000_2026.07.30.741854v2.36","doi-asserted-by":"crossref","first-page":"e0009868","DOI":"10.1371\/journal.pntd.0009868","article-title":"Diversity and distribution of the tick-borne relapsing fever spirochete Borrelia turicatae","volume":"15","year":"2021","journal-title":"PLoS Negl Trop Dis"},{"key":"2026080500400457000_2026.07.30.741854v2.37","doi-asserted-by":"publisher","DOI":"10.1186\/s12864-022-08523-7"},{"key":"2026080500400457000_2026.07.30.741854v2.38","first-page":"e00895","article-title":"Comparative genomics analysis of three conserved plasmid families in the Western Hemisphere soft tick-borne relapsing fever borreliae provides insight into variation in genome structure and antigenic variation systems","volume":"11","year":"2023","journal-title":"Microbiol Spectr"},{"key":"2026080500400457000_2026.07.30.741854v2.39","doi-asserted-by":"crossref","first-page":"jkaf103","DOI":"10.1093\/g3journal\/jkaf103","article-title":"Genome report: whole-genome assembly of the relapsing fever tick Ornithodoros turicata Dug\u00e8s (Acari: Argasidae)","volume":"15","year":"2025","journal-title":"G3 (Bethesda)"},{"key":"2026080500400457000_2026.07.30.741854v2.40","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-021-81252-1"},{"key":"2026080500400457000_2026.07.30.741854v2.41","doi-asserted-by":"publisher","DOI":"10.1128\/JCM.43.8.3851-3859.2005"},{"key":"2026080500400457000_2026.07.30.741854v2.42","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0147707"},{"key":"2026080500400457000_2026.07.30.741854v2.43","doi-asserted-by":"publisher","DOI":"10.2307\/1931961"},{"key":"2026080500400457000_2026.07.30.741854v2.44","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pntd.0002767"},{"key":"2026080500400457000_2026.07.30.741854v2.45","doi-asserted-by":"publisher","DOI":"10.1007\/978-1-60327-032-8_6"},{"key":"2026080500400457000_2026.07.30.741854v2.46","first-page":"521","article-title":"Isolation and cultivation of Lyme disease spirochetes","volume":"57","year":"1984","journal-title":"Yale J Biol Med"},{"key":"2026080500400457000_2026.07.30.741854v2.47","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0502565102"},{"key":"2026080500400457000_2026.07.30.741854v2.48","doi-asserted-by":"publisher","DOI":"10.1111\/mmi.14609"},{"key":"2026080500400457000_2026.07.30.741854v2.49","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pbio.3001066"},{"key":"2026080500400457000_2026.07.30.741854v2.50","unstructured":"Signorell A , Aho K , Alfons A , Anderegg N , Aragon T , Arppe A , Baddeley A , Barton K , Bolker B , Borchers HW . 2019. DescTools: Tools for descriptive statistics, Version 0.99.58."},{"key":"2026080500400457000_2026.07.30.741854v2.51","unstructured":"Torchiano M . 2020. Package \u2018effsize\u2019, vVersion 0.8.1."},{"key":"2026080500400457000_2026.07.30.741854v2.52","unstructured":"Meissel K , Yao ES . 2024. Using Cliff\u2019s delta as a non-parametric effect size measure: an accessible web app and R tutorial. Pract Assess Res Eval 29."}],"container-title":[],"original-title":[],"link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.64898\/2026.07.30.741854","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T07:40:20Z","timestamp":1785915620000},"score":1,"resource":{"primary":{"URL":"http:\/\/biorxiv.org\/lookup\/doi\/10.64898\/2026.07.30.741854"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,31]]},"references-count":52,"URL":"https:\/\/doi.org\/10.64898\/2026.07.30.741854","relation":{},"subject":[],"published":{"date-parts":[[2026,7,31]]},"subtype":"preprint"}}