title: 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.
abstract: Relapsing fever (RF) spirochetes colonize and are transmitted to mammals primarily byOrnithodorosticks, and little is known regarding the pathogen's life cycle in the vector. To further understand vector colonization and transmission of RF spirochetes,Borrelia turicataeexpressing a green fluorescent protein (GFP) marker (B. turicatae-gfp) was generated. The transformants were evaluated during the tick-mammal infectious cycle, from the third nymphal instar to adult stage.B. turicatae-gfpremained viable for at least 18 months in starved fourth-stage nymphal ticks, and the studies indicated that spirochete populations persistently colonized the tick midgut and salivary glands. Our generation ofB. turicatae-gfpalso revealed that within the salivary glands, spirochetes are localized in the ducts and lumen of acini, and after tick feeding, the tissues remained populated with spirochetes. TheB. turicatae-gfpgenerated in this study is an important tool to further understand and define the mechanisms of vector colonization and transmission.IMPORTANCEIn order to interrupt the infectious cycle of tick-borne relapsing fever spirochetes, it is important to enhance our understanding of vector colonization and transmission. Toward this, we generated a strain ofBorrelia turicataethat constitutively produced the green fluorescent protein, and we evaluated fluorescing spirochetes during the entire infectious cycle. We determined that the midgut and salivary glands ofOrnithodoros turicataticks maintain the pathogens throughout the vector's life cycle and remain colonized with the spirochetes for at least 18 months. We also determined that the tick's salivary glands were not depleted after a transmission blood feeding. These findings set the framework to further understand the mechanisms of midgut and salivary gland colonization.
authors.affiliation: Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Aparna
authors.initials: A
authors.lastname: Krishnavajhala
authors.affiliation: Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Hannah K
authors.initials: HK
authors.lastname: Wilder
authors.affiliation: Department of Biological Sciences, Mississippi State University, Starkville, Mississippi, USA.
authors.forename: William K
authors.initials: WK
authors.lastname: Boyle
authors.affiliation: Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Ashish
authors.initials: A
authors.lastname: Damania
authors.affiliation: Department of Biological Sciences, Mississippi State University, Starkville, Mississippi, USA.
authors.forename: Justin A
authors.initials: JA
authors.lastname: Thornton
authors.affiliation: U.S. Department of Agriculture-Agricultural Research Service, Knipling-Bushland U.S. Livestock Insects Research Laboratory and Veterinary Pest Genomics Center, Kerrville, Texas, USA.
authors.forename: Adalberto A
authors.initials: AA
authors.lastname: Pérez de León
authors.affiliation: Department of Entomology, Texas A&M AgriLife Research, Texas A&M University, College Station, Texas, USA.
authors.forename: Pete D
authors.initials: PD
authors.lastname: Teel
authors.affiliation: Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, USA job.lopez@bcm.edu.|Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Job E
authors.initials: JE
authors.lastname: Lopez
mesh_terms: D000818:Animals; D001179:Arthropod Vectors / Q000382:microbiology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D015415:Biomarkers; D001898:Borrelia / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D004269:DNA, Bacterial; D004064:Digestive System / Q000382:microbiology*; D004195:Disease Models, Animal; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D049452:Green Fluorescent Proteins / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D009758:Nymph / Q000382:microbiology*; D026861:Ornithodoros / Q000382:microbiology*; D012061:Relapsing Fever / Q000097:blood / Q000382:microbiology / Q000635:transmission*; D012469:Salivary Glands / Q000382:microbiology* / Q000473:pathology
chemical_list: D001426:Bacterial Proteins; D015415:Biomarkers; D004269:DNA, Bacterial; D049452:Green Fluorescent Proteins
keywords: Borrelia turicatae; Ornithodoros; argasid; relapsing fever spirochetes; soft tick; vector colonization