title: Transcriptional Profiling the 150 kb Linear Megaplasmid of Borrelia turicatae Suggests a Role in Vector Colonization and Initiating Mammalian Infection.
abstract: Adaptation is key for survival as vector-borne pathogens transmit between the arthropod and vertebrate, and temperature change is an environmental signal inducing alterations in gene expression of tick-borne spirochetes. While plasmids are often associated with adaptation, complex genomes of relapsing fever spirochetes have hindered progress in understanding the mechanisms of vector colonization and transmission. We utilized recent advances in genome sequencing to generate the most complete version of the Borrelia turicatae 150 kb linear megaplasmid (lp150). Additionally, a transcriptional analysis of open reading frames (ORFs) in lp150 was conducted and identified regions that were up-regulated during in vitro cultivation at tick-like growth temperatures (22°C), relative to bacteria grown at 35°C and infected murine blood. Evaluation of the 3' end of lp150 identified a cluster of ORFs that code for putative surface lipoproteins. With a microbe's surface proteome serving important roles in pathogenesis, we confirmed the ORFs expression in vitro and in the tick compared to spirochetes infecting murine blood. Transcriptional evaluation of lp150 indicates the plasmid likely has essential roles in vector colonization and/or initiating mammalian infection. These results also provide a much needed transcriptional framework to delineate the molecular mechanisms utilized by relapsing fever spirochetes during their enzootic cycle.
authors: Department of Pediatrics, Section of Tropical Medicine, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas, United States of America.
authors: Hannah K
authors: HK
authors: Wilder
authors: Laboratory of Zoonotic Pathogens, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America.
authors: Sandra J
authors: SJ
authors: Raffel
authors: Departments of Microbiology & Molecular Genetics, Medicine, and Ecology and Evolutionary Biology, University of California Irvine, Irvine, California, United States of America.
authors: Alan G
authors: AG
authors: Barbour
authors: Genomics Unit, Research Technologies Section, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America.
authors: Stephen F
authors: SF
authors: Porcella
authors: Genomics Unit, Research Technologies Section, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America.
authors: Daniel E
authors: DE
authors: Sturdevant
authors: Igenbio, Inc., Chicago, IL, United States of America.
authors: Benjamin
authors: B
authors: Vaisvil
authors: Igenbio, Inc., Chicago, IL, United States of America.
authors: Vinayak
authors: V
authors: Kapatral
authors: Igenbio, Inc., Chicago, IL, United States of America.
authors: Daniel P
authors: DP
authors: Schmitt
authors: Laboratory of Zoonotic Pathogens, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America.
authors: Tom G
authors: TG
authors: Schwan
authors: Department of Pediatrics, Section of Tropical Medicine, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas, United States of America.|Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America.
authors: Job E
authors: JE
authors: Lopez
mesh_terms: D000818:Animals; D001898:Borrelia / Q000235:genetics*; D019295:Computational Biology / Q000379:methods; D020451:Contig Mapping; D004195:Disease Models, Animal; D004199:Disease Vectors; D015870:Gene Expression; D020869:Gene Expression Profiling; D023061:Gene Order; D008193:Lyme Disease / Q000382:microbiology; D051379:Mice; D058977:Molecular Sequence Annotation; D016366:Open Reading Frames; D010957:Plasmids / Q000235:genetics*; D013987:Ticks / Q000382:microbiology; D059467:Transcriptome