Education

B.A. Colorado College, 1983

Ph.D. University of Arizona, 1991

Courses Taught

BIOB 260 Cellular and Molecular Biology

BIOB 160N Principles of Living Systems

BCH 380 Biochemistry

Research Interests

Research in our laboratory focuses on the spirochete Borrelia (Borreliella) burgdorferi, the etiologic agent of Lyme disease. The enzootic life cycle of B. burgdorferi involves a tick vector and a vertebrate host: different sets of genes are expressed in these diverse environments. We are primarily interested in the molecular mechanisms by which the spirochete senses that the tick vector is feeding on a vertebrate host and subsequently regulates its gene expression to effect transmission. We also study the cellular mechanisms required for persistence of B. burgdorferi in the tick vector.

We dissect the roles of alternative sigma factors, the stringent response and transcription factors as well as small RNAs, RNA chaperones and ribonucleases in the regulation of gene expression and in response to changes in nutrient availability. In addition, we are interested in the molecular physiology of the spirochete because of its unusual bacterial genome, in particular the biology of its bacteriophage, the biogenesis of its ribosomal RNAs, and the replication of its linear DNA. Furthermore, we have been involved in developing molecular genetic tools to address these research questions, including a system to artificially regulate transcription in B. burgdorferi in an enzootic cycle model.

Projects

Biology of Spirochetes Gordon Research Conference

Field of Study

Molecular borreliology

Selected Publications

Van Gundy, T., Patel, D., Bowler, B.E., Rothfuss, M.T., Hall, A.J., Davies, C., Hall, L.S., Drecktrah, D., Marconi, R.T., Samuels, D.S., and Lybecker, M.C. (2023) c-di-GMP regulates activity of the PlzA RNA chaperone from the Lyme disease spirochete. Mol. Microbiol. 119: 711-727.

Drecktrah, D., Hall, L.S., Crouse, B., Schwarz, B., Richards, C., Bohrnsen, E., Wulf, M., Long, B., Bailey, J., Gherardini, F., Bosio, C.M., Lybecker, M.C., and Samuels, D.S. (2022) The glycerol-3-phosphate dehydrogenases GpsA and GlpD constitute the oxidoreductive metabolic linchpin for Lyme disease spirochete host infectivity and persistence in the tick. PLoS Pathog. 18: e1010385.

Drecktrah, D., Hall, L.S., Brinkworth, A.J., Comstock, J.R., Wassarman, K.M., and Samuels, D.S. (2020) Characterization of 6S RNA in the Lyme disease spirochete. Mol. Microbiol. 113: 399-417. (Cover)

Drecktrah, D., Lybecker, M., Popitsch, N., Rescheneder, P., Hall, L.S., and Samuels, D.S. (2015) The Borrelia burgdorferi RelA/SpoT homolog and stringent response regulate survival in the tick vector and global gene expression during starvation. PLoS Pathog. 11: e1005160.

Lybecker, M.C., Abel, C.A., Feig, A.L., and Samuels, D.S. (2010) Identification and function of the RNA chaperone Hfq in the Lyme disease spirochete Borrelia burgdorferi. Mol. Microbiol. 78: 622-635.

Gilbert, M.A., Morton, E.A., Bundle, S.F., and Samuels, D.S. (2007) Artificial regulation of ospC expression in Borrelia burgdorferi. Mol. Microbiol. 63: 1259-1273.

Alverson, J., Bundle, S.F., Sohaskey, C.D., Lybecker, M.C., and Samuels, D.S. (2003) Transcriptional regulation of the ospAB and ospC promoters from Borrelia burgdorferi. Mol. Microbiol. 48:1665-1677.

Eggers, C.H., Kimmel, B.J., Bono, J.L., Elias, A., Rosa, P., and Samuels, D.S. (2001) Transduction by ϕBB-1, a bacteriophage of Borrelia burgdorferi. J. Bacteriol. 183:4771-4778.

Knight, S.W. and Samuels, D.S. (1999) Natural synthesis of a DNA-binding protein from the C-terminal domain of DNA gyrase A in Borrelia burgdorferi. EMBO J. 18:4875-4881.

Publications

Full list of publications via NCBI.

Publications via Google Scholar.

Book chapters, commentary, and reviews:

Samuels, D.S, Lybecker, M.C., Yang, X.F., Ouyang, Z., Bourret, T.J., Boyle, W.K., Stevenson, B., Drecktrah, D., and Caimano, M.J. (2021) Gene regulation and transcriptomics. In: Radolf, J.D. and Samuels, D.S. (eds.) Lyme Disease and Relapsing Fever Spirochetes: Genomics, Molecular Biology, Host Interactions, and Disease Pathogenesis, pp. 87-130. Caister Academic Press, Norfolk, England. Available as a review in: Curr. Issues Mol. Biol. 42: 223-266 (2021).

Samuels, D.S., Drecktrah, D., and Hall, L.S. (2018) Genetic transformation and complementation, Chapter 15. In: Pal, U. and Buyuktanir, O. (eds.) Methods in Molecular Biology, vol. 1690: Borrelia burgdorferi: Methods and Protocols, pp. 183-200. Humana Press, New York NY.

Drecktrah D. and Samuels, D.S. (2018) Genetic manipulation of Borrelia spp. In: Adler, B. (ed.) Curr. Top. Microbiol. Immunol, vol. 415: Spirochete Biology: The Post Genomic Era, pp. 113-140. Springer, Cham, Switzerland.

Lybecker, M.C. and Samuels, D.S. (2017) Small RNAs of Borrelia burgdorferi: characterizing functional regulators in a sea of sRNAs. Yale J. Biol. Med. 90: 317-323.

Samuels, D.S. and Samuels, L.R.N. (2016) Gene regulation during the enzootic cycle of the Lyme disease spirochete. For. Immunopathol. Dis. Therap. 7: 205-212.

Caimano, M.J., Drecktrah, D., Kung, F., and Samuels, D.S. (2016) Interaction of the Lyme disease spirochete with its tick vector. Cell. Microbiol. 18: 919-927. (Cover)

Brisson, D., Drecktrah, D., Eggers, C.H., and Samuels, D.S. (2012) Genetics of Borrelia burgdorferi. Annu. Rev. Genet. 46: 513-534.

Samuels, D.S. (2011) Gene regulation in Borrelia burgdorferi. Annu. Rev. Microbiol. 65: 479-499.

Rosa, P.A., Cabello, F., and Samuels, D.S. (2010) Genetic manipulation of Borrelia burgdorferi. In: Samuels, D.S. and Radolf, J.D. (eds.) Borrelia: Molecular Biology, Host Interaction and Pathogenesis, pp. 189-219. Caister Academic Press, Norfolk, England.  

Skare, J.T., Carroll, J.A., Yang, X.F., Samuels, D.S., and Akins, D.R. (2010) Gene regulation, transcriptomics, and proteomics. In: Samuels, D.S. and Radolf, J.D. (eds.) Borrelia: Molecular Biology, Host Interaction and Pathogenesis, pp. 67-101. Caister Academic Press, Norfolk, England.

Samuels, D.S. and Radolf, J.D. (2009) Who is the BosR around here anyway? Mol. Microbiol. 74: 1295-1299.

Samuels, D.S. (2006) Antibiotic resistance in Borrelia burgdorferi: applications for genetic manipulation and implications for evolution. In: Cabello, F.C., Hulinska, D., and Godfrey, H.P. (eds.) Molecular Biology of Spirochetes, pp. 56-70. IOS Press, Amsterdam, Netherlands.

Eggers, C.H., Casjens, S. and Samuels, D.S. (2001) Bacteriophages of Borrelia burgdorferi and other spirochetes, Chapter 4. In: Saier, Jr., M.H. and García-Lara, J. (eds.) The Spirochetes: Molecular and Cellular Biology, pp. 35-44. Horizon Scientific Press, Wymondham, United Kingdom.

Eggers, C.H., Casjens, S., Hayes, S.F., Garon, C.F., Damman, C.J., Oliver, D.B., and Samuels, D.S. (2000) Bacteriophages of spirochetes. J. Mol. Microbiol. Biotechnol. 2: 365-373.

Samuels, D.S. (1995) Electrotransformation of the spirochete Borrelia burgdorferi, Chapter 25. In: Nickoloff, J.A. (ed.) Methods in Molecular Biology, vol. 47: Electroporation Protocols for Microorganisms, pp. 253-259. Humana Press, Totowa NJ.

Books:

Radolf, J.D. and Samuels, D.S., eds. (2021) Lyme Disease and Relapsing Fever Spirochetes: Genomics, Molecular Biology, Host Interactions, and Disease Pathogenesis. Caister Academic Press, Norfolk, England.

Samuels, D.S. and Radolf, J.D., eds. (2010) Borrelia: Molecular Biology, Host Interaction and Pathogenesis. Caister Academic Press, Norfolk, England.

Brownian motion (it is a long story):

Pearle, P., Collett, B., Bart, K., Bilderback, D., Newman, D., and Samuels, S. (2010) What Brown saw and you can too. Am. J. Phys. 78: 1278-1289.

Hobbies

Running, hiking, backpacking, bicycling, and skiing.