Development of genetic system to inactivate a Borrelia turicatae surface protein selectively produced within the salivary glands of the arthropod vector

PLoS Negl Trop Dis. 2013 Oct 31;7(10):e2514. doi: 10.1371/journal.pntd.0002514. eCollection 2013.


Background: Borrelia turicatae, an agent of tick-borne relapsing fever, is an example of a pathogen that can adapt to disparate conditions found when colonizing the mammalian host and arthropod vector. However, little is known about the genetic factors necessary during the tick-mammalian infectious cycle, therefore we developed a genetic system to transform this species of spirochete. We also identified a plasmid gene that was up-regulated in vitro when B. turicatae was grown in conditions mimicking the tick environment. This 40 kilodalton protein was predicted to be surface localized and designated the Borrelia repeat protein A (brpA) due to the redundancy of the amino acid motif Gln-Gly-Asn-Val-Glu.

Methodology/principal findings: Quantitative reverse-transcriptase polymerase chain reaction using RNA from B. turicatae infected ticks and mice indicated differential regulation of brpA during the tick-mammalian infectious cycle. The surface localization was determined, and production of the protein within the salivary glands of the tick was demonstrated. We then applied a novel genetic system for B. turicatae to inactivate brpA and examined the role of the gene product for vector colonization and the ability to establish murine infection.

Conclusions/significance: These results demonstrate the complexity of protein production in a population of spirochetes within the tick. Additionally, the development of a genetic system is important for future studies to evaluate the requirement of specific B. turicatae genes for vector colonization and transmission.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Bacterial Proteins / biosynthesis*
  • Bacterial Proteins / genetics*
  • Borrelia / genetics*
  • Borrelia / metabolism*
  • DNA, Bacterial / chemistry
  • DNA, Bacterial / genetics
  • Gene Expression Profiling
  • Gene Knockout Techniques*
  • Host-Pathogen Interactions*
  • Membrane Proteins / biosynthesis
  • Membrane Proteins / genetics
  • Mice
  • Molecular Sequence Data
  • Plasmids
  • Real-Time Polymerase Chain Reaction
  • Salivary Glands / parasitology
  • Sequence Analysis, DNA
  • Ticks / parasitology*


  • Bacterial Proteins
  • DNA, Bacterial
  • Membrane Proteins

Associated data

  • GENBANK/KC859623
  • GENBANK/KC859624
  • GENBANK/KC859625
  • GENBANK/KC859626
  • GENBANK/KC859627
  • GENBANK/KC859628
  • GENBANK/KC859629