Many bacteria coordinate group behaviors through cell-cell communication, including quorum sensing and other signaling pathways that regulate virulence, biofilm formation, cooperation, and competition. These interactions can occur within a single species or across mixed-species communities, where communication and metabolic exchange can alter pathogen growth, antibiotic tolerance, and the production of virulence factors.

Our lab studies how bacterial communication and spatial organization shape infection-relevant behaviors. We ask how biofilm structure, ecological interactions, and population dynamics control the expression of virulence factors in organisms such as Pseudomonas aeruginosa and Staphylococcus aureus. By identifying ways to disrupt communication, disturb biofilm organization, or alter cooperative behaviors, we aim to develop new strategies that slow infection progression and reduce reliance on escalating antibiotic treatment. These approaches may help preserve the effectiveness of existing antibiotics by targeting the social and ecological processes that make bacterial communities difficult to treat.

García-Diéguez, L., Diaz-Tang, G., Meneses, E. M., Cruise, V., Barraza, I., Craddock, T. J., & Smith, R. P. (2023). Periodically disturbing biofilms reduces expression of quorum sensing-regulated virulence factors in Pseudomonas aeruginosa. Iscience, 26(6).

Pajon, C., Fortoul, M. C., Diaz-Tang, G., Meneses, E. M., Mariah, T., Toscan, B., ... & Smith, R. P. (2022). Interactions between metabolism and growth can determine the co-existence of Staphylococcus aureus and Pseudomonas aeruginosa. eLife. 12., e83664,

Barraza, I., Pajon, C., Diaz-Tang, G., Marin Meneses, E., Abu-Rumman, F., García-Diéguez, L., Castro, V., Lopatkin, A.J. and Smith, R.P. (2023). Disturbing the Spatial Organization of Biofilm Communities Affects Expression of agr-Regulated Virulence Factors in Staphylococcus aureus. Applied and Environmental Microbiology, pp.e01932-22.

Quinn RJ, Barraza I, García-Diéguez L, Pajon C, Krausfeldt LE, Ibrahim K, Enzinna LA, Thorn ME, Eldakar OT, Craddock TJA, Smith RP (2021). Periodically disturbing the spatial structure of biofilms can affect the production of an essential virulence factor in Pseudomonas aeruginosa. mSystems 0:e00961-21.

Smith, RP., Barraza, I., Quinn, RJ, and Fortoul. M.C., (2020) The mechanisms and cell signaling pathways of programmed cell death in the bacterial world." In International Review of Cell and Molecular Biology, vol. 352, pp. 1-53. Academic Press

Dressler, MD., Clark, C.J., Thachettu, C.A.,  Zakaria,Y.,  Eldakar, O.T., and Smith, R.P. (2017) Synthetically engineered microbes reveal interesting principles of cooperation." Frontiers of Chemical Science and Engineering 11, no. 1: 3-14.

Dressler, M.D.,   Conde, J.,  Eldakar, O.T., and Smith, R.P. (2019) The timing between introduction events determines population establishment success in bacteria with an Allee effect. Proceedings of the Royal Society B. 286: 1902: 20190598

Wilson, C. E.,   Lopatkin, A. J., Craddock, T. J., Driscoll, W. W., Eldakar, O. T., Lopez, J. V., & Smith, R. P. (2017). Cooperation and competition shape ecological resistance during periodic spatial disturbance of engineered bacteria. Scientific Reports, 7.

Smith, RP, Tan, C., Srimani, J.K., Pai, A., Riccione, K.A., Song, H. and You, L., 2014. Programmed Allee effect in bacteria causes a tradeoff between population spread and survival. Proceedings of the National Academy of Sciences, 111(5), pp.1969-1974.