Profile for Daniel Bretl

Research and publishing

My research interests revolve around how bacteria sense their environment to coordinate cellular responses. In other words, I'm interested in how bacteria "know" what to do and when to do it. To study these systems, my lab employs several genetic and biochemical techniques.

More specifically, I study the role of a particular type of signaling system known as a two-component signaling system. These systems are found in all bacteria and are critical to their lifecycle and behaviors. To study two-component systems, my research utilizes the bacterial species Myxococcus xanthus. This is a fascinating species that is found in the soil and has complex social behaviors that include cooperative motility, microbial predation, and multi-cellular development.

Selected recent publications (* = undergraduate):

1. Bretl, D.J., A. Elfessi, H. Watkins, W.R. Schwan. 2019. Regulation of the superantigen-like protein 1 gene of community-associated methicillin-resistant Staphylococcus aureus in murine abscesses. Toxins. 11, 391.
2. Bretl, D.J., K.M. Ladd*, S.N. Atkinson, S. Muller, and J.R. Kirby. Suppressor Mutations Reveal an NtrC-like Response Regulator, NmpR, for Modulation of Type-IV Pili-Dependent Motility in Myxococcus xanthus. 2018. PloS Genetics. 14(10):e1007714.
3. Bretl, D.J., and J.R. Kirby. 2016. Molecular mechanisms of signaling in Myxococcus xanthus J. of Mol Biol. 428(19):3805-30. Review.
4. Bretl, D.J., S. Muller, K.M. Ladd*, S.N. Atkinson, and J.R. Kirby. 2016. Type IV-pili Dependent Motility is Co-regulated by PilSR and PilS2R2 Two-component Systems via Distinct Pathways in Myxococcus xanthus. Mol. Microbiol. 102(1):37-53.
5. Armstrong, R.M., K.L. Adams, J.E. Zilisch, J. Bretl, H. Sato, D.M. Anderson, and T.C. Zahrt. 2016. Rv2744c is a PspA ortholog that regulates lipid droplet homeostasis and non-replicating persistence in Mycobacterium tuberculosis. J of Bacteriol. 198(11):1645-1661.
6. Kommineni, S., J. Bretl, V. Lam, R. Chakraborty, M. Hayward, P. Simpson, Y. Cao, P Bousounis, C.J. Kristich, and N.H. Salzman. 2015. Bacteriocin production augments niche competition by enterococci in the mammalian gastrointestinal tract. Nature. 526(7575):719-722.
7. Bretl, D.J., T.M. Bigley, S.S. Terhune, and T.C. Zahrt. 2014. The MprB extracytoplasmic domain negatively regulates activation of the Mycobacterium tuberculosisMprAB two-component system. Bacteriol. 196:391-406.
8. Bretl, D.J., and T.C Zahrt. 2013. Regulation of envelope stress responses by Mycobacterium tuberculosis. In L Vasil and A.J. Darwin (ed.),Regulation of bacterial virulence, American Society for Microbiology, Washington, D.C.
9. Bretl, D.J., H. He, C. Demetriadou, M.J. White, R.M. Penoske, N.H. Salzman, and T.C. Zahrt. 2012. MprA and DosR coregulate a Mycobacterium tuberculosis virulence operon encoding Rv1813c and Rv1812c. Infect Immun. 80:3018-3033.
10. Bretl, D.J., C. Demetriadou, and T.C. Zahrt. 2011. Adaptation to environmental stimuli within the host: two-component signal transduction systems of Mycobacterium tuberculosis. Microbiol Mol Biol Rev. 75:566-582.
11. He, H., J. Bretl, R.M. Penoske, D.M. Anderson, and T.C. Zahrt. 2011. Components of the Rv0081-Rv0088 locus, which encodes a predicted formate hydrogenlyase complex, are coregulated by Rv0081, MprA, and DosR in Mycobacterium tuberculosis. J Bacteriol. 193:5105-5118.
12. White, M.J., J.P. Savaryn, J. Bretl, H. He, R.M. Penoske, S.S. Terhune, and T.C. Zahrt. 2011. The HtrA-like serine protease PepD interacts with and modulates the Mycobacterium tuberculosis 35-kDa antigen outer envelope protein. PloS One. 6:e18175.