Paul Stoodley, Ph.D. Associate Professor Microbiology and Immunology Vice Director of Imaging, Center for Genomic Sciences, ASRI 320 East North Avenue Pittsburgh, PA 15212 Phone: 412-359-6876 Fax: 412-359-6995 Email: pstoodle@wpahs.org Ph.D., 1999, Exeter University, Exeter, United Kingdom

Keywords:

Biofilm, hydrodynamics, dispersal, antibiotic resistance, FISH, confocal microscopy

Research Interests:

Biofilm dynamic behavior in progression of infectious disease, influence of hydrodynamics and mass transfer on biofilm processes, biofilm development in environmental ecosystems, and biofilm mechanics and disruption.

Fundamental biofilm processes
Bacterial biofilms are communities of bacteria that form on surfaces. Biofilms can cause infection of both artificial devices, such as catheters, as well as human tissue. They can contaminate everything from industrial plants to household drains. The bacteria often produce a protective extracellular polymeric slime (EPS) matrix that binds them together and to the surface. My research focuses on microbial biofilms utilizing a multidisciplinary approach drawn from Microbiology, and Civil, Chemical and Mechanical Engineering. Using a combination of flow-cell based biofilm culturing systems coupled with confocal and time-lapse imaging techniques we are investigating the role of both extrinsic and intrinsic factors such as fluid shear, nutrients, and cell signaling molecules on biofilm formation and dynamic behavior.  One aspect of my work has been to describe mass transfer phenomena as related to biofilm heterogeneity and how convective mass transfer within biofilm channels, demonstrated that these channels could facilitate nutrient exchange. By observing biofilms growing under different flow regimes we have showed that fluid shear had a dramatic impact on structure and could even override bacterial cell-signaling mechanisms, illustrating the importance of extrinsic environmental conditions on biofilm development. I am also interested in the natural dispersal of bacteria form biofilms and am currently looking for genes that may be responsible for this process. In addition to the biological interest there is potential for developing novel dispersal based treatment strategies.

Biofilm mechanics
My interest in the interaction of biofilms with flowing fluids has led to the development of rheometry and microfluidics based methodologies to measure the material properties of biofilms. These works have resulting in the opening up of a novel field: “Biofilm mechanics”. All biofilms that we have investigated so far (medical and dental pathogens, hydrothermal bacterial, hydrothermal algae, and pond water microbial communities) have demonstrated remarkably similar viscoelastic behavior. This commonality suggests that the viscoelastic properties of diverse biofilms are a convergent adaptation to survival on surfaces in flowing environments, man-made surfaces, and mammalian hosts. We believe that the EPS governs the material properties of the complete biofilm and that our research will allow us to explore mechanical and enzymatic means in which to disrupt biofilms.

Biofilms in clinical specimens
More recently we have been using fluorescent in situ hybridization (FISH), viability staining, immunofluorescence and microelectrodes to detect biofilms associated with infected sutures, prosthetic joints and adenoid and middle ear biopsies. Often classical sampling and culture techniques are not effective and biofilms often go undetected. We hope to improve diagnostics and through our research bring a “biofilm-based” strategy to the management of these biofilm diseases.

My broad research experience and diverse interests have led to a number of funded research projects including projects in: medical biofilms (NIH), environmental biofilms (Keck), dental and industrial (Philips Oral Healthcare), and defense-related projects (DOD and DARPA). In addition to my academic research experience I have also worked in a consulting capacity to assess biofouling and product contamination in nuclear, pharmaceutical, and domestic product production plants.

Selected Publications:

1. Purevdorj-Gage B., Orr M., Stoodley P., Sheehan K.B., and Hyman L.E. 2007. The role of the FLO11 in S. cerevisiae adhesion and biofilm development in a laboratory based flow-cell system. FEMS Yeast Research. In press.
2. LaFramboise, W.A., Scalise, D., Stoodley, P., Graner, S.R., Guthrie, R.D., Magovern, J.A. 2007. Cardiac fibroblasts influence cardiomyocyte phenotype in vitro. A.J. Physiology -Cell Physiology.  In press.
3. Horswill, A.R., Stoodley, P. Stewart, P.S. and Parsek, M.R. 2007. The impact of the chemical, biological, and physical environment on quorum sensing in structured microbial communities. Analytical and Bioanalytical Chemistry. 387(2):371-380.
4. Towler, B., Stoodley, P., Cunningham, A.B. and McKittrick, L. 2007. A model of fluid-biofilm interaction using a burger material law. Biotech. Bioeng. 96(2):259-271.
5. Hall-Stoodley, L.,  Hu, F.Z., Gieseke, A., Nistico, L., Nguyen, D., Hayes, J., Forbes, M., Greenberg, D.P., Dice, B., Burrows A., Stoodley, P., Post, J.C., Ehrlich G.D., and Kerschner, J. 2006. Direct detection of bacterial biofilms on the middle-ear mucosa of children with chronic otitis media [Clinical investigation]. JAMA. 296(2):202-211.
6. Stoodley, P., Dodds, I., de Beer, D., Lappin Scott, H.M., Boyle, J.D. 2005. Flowing biofilms as a transport mechanism for biomass through porous media under laminar and turbulent conditions in a laboratory reactor system. Biofouling. 21(3/4):161–168.
7. Stoodley, P., Kathju, S., Hu, F.Z., Erdos, G., Levenson, J.E., Mehta, N.S., Dice, B.L., Johnson, S.L.,  Hall-Stoodley, L., Nistico, L., Sotereanos, N.G., Sewecke, J.J., Post, J.C. and Ehrlich, G.D. 2005. Molecular and imaging techniques for bacterial biofilms in arthroplastic joint infections. Clinical orthopaedics and related research. 437:31-40.
8. Balaban, N.,  Stoodley, P., Fux, C.A., Wilson, S., Costerton, J.W., Dell’Acqua, G. 2005. Prevention of Staphylococcal biofilms-associated infections by the quorum sensing inhibitor RIP. Clinical Orthopaedics and Related Research. 437:48-54.
9. Braxton, E.E., Ehrlich, G.D., Hall-Stoodley, L. Stoodley, P., Veeh, R., Fux, C., Hu, F.Z. Quigley, M., and Post, J.C. 2005. The Role of Biofilms in Neurosurgical Device-Related Infections. Neurosurgical Review. 28(4):249-55.
10. Norris, P., Noble, M., Francolini, I., Vinogradov, A., Stewart, P.S., Ratner, B., Costerton, J.W. and Stoodley, P. 2005.  Ultrasonically controlled release of ciprofloxacin from self-assembled coatings on pHEMA hydrogels for Pseudomonas aeruginosa biofilm prevention. Antimicobial. Agents Chemo. 49(10):4272–4279.
11. Purevdorj-Gage, B., Costerton, J.W. and Stoodley, P. 2005. Phenotypic differentiation and seeding dispersal in non-mucoid and mucoid Pseudomonas aeruginosa biofilms. Microbiology (151):1569-1576.
12. Rupp, C.J., Fux, C. and Stoodley, P. 2005. Viscoelasticity of Staphylococcus aureus biofilms in response to fluid shear resists detachment and facilitates rolling migration. Appl. Envron. Microbiol. 71(4): 2175–2178.
13. Fux, C.A.., Shirtliff, M., Stoodley, P. and Costerton J.W. 2005. Can laboratory reference strains mirror ‘real-world’ pathogenesis? Trends in Microbiology. 13(2): 58-63.
14. Hall-Stoodley, L. and Stoodley, P. 2005. Biofilm formation and the transmission of human pathogens. Trends in Microbiology. 13(1):7-10.
15. Hall-Stoodley, L., Costerton, J.W., and Stoodley, P. 2004. Bacterial biofilms: From the environment to infectious disease. Nature Reviews Microbiology. 2(2): 95-108.