Reconstitution of Microbial Communities of CF Infants

Project Leader and Investigator

George A O'Toole, Ph.D.
Professor, Microbiology and Immunology Geisel School of Medicine at Dartmouth

Research in the O'Toole lab focuses on the formation of bacterial biofilms on biotic and abiotic surfaces. A central interest of the group is to study the biofilms that form in patients with Cystic Fobrosis (CF). Pulmonary damage caused by chronic colonization of the CF lung by microbial communities is the proximal cause of respiratory failure. While there has been an effort to document the microbiome of the CF lung in pediatric and adult patients, little is known regarding the developing microflora in infants and children. To date, we have examined the respiratory microbiota development in ~20 infants and children with CF from birth up to ~4 yrs. Our central hypothesis is that we can recapitulate key aspects of the polymicrobial communities in the laboratory by growing polymicrobial biofilms on CF airway cells, thereby gaining a greater understanding of the nature of these interactions and developing a platform to test new therapeutic agents. Towards this end, COBRE funding has supported our studies utilizing interaction analysis and mixed effects models to analyze the microbiome data from the respiratory tract of CF infants/children and identify correlations among microbes in this cohort. These statistical analyses have served to guide and focus our preliminary in vitro studies on those microbes most likely to interact and impact pathogenesis in the context of the CF lung. Guided by the analysis of our microbiome data, we have examined dozens of pairwise combinations of microbes growing on CF-derived airway cells. Our preliminary data show that mixing P. aeruginosa with Staphylococcus aureus, an early colonizer of the CF lung, results in the eventual loss of viability of S. aureus, suggesting that P. aeruginosa can outcompete S. aureus when co-cultured with CF-derived cells, an observation consistent with numerous clinical studies. More recent work has established potential mechanisms by which P. aeruginosa can outcompete S. aureus, and we propose in vitro studies and patient sample analyses to confirm and extend these findings.

Lab Members

Sherry Kuchma, Senior Scientist
Regulation of biofilm formation by Pseudomonas aeruginosa

Michael Zegans, M.D., Physician-scientist
Study of biofilms and the microbiome of the eye

Dae-Gon Ha, Ph.D. student
Regulation of biofilm formation in Pseudomonas aeruginosa by cyclic-di-GMP

Laura Filkins, Ph.D. student
COBRE project: Reconstitution of microbial communities of CF infants

Kurt Dahlstrom, Ph.D. student
Biofilm formation by a soil pseudomonad

Gary Heussler, Ph.D. student
CRISPR-mediated regulation of surface behaviors

Amy Baker, Ph.D. student
Regulation of biofilm formation and surface motility by Pseudomonas aeruginosa

Katie Price, Ph.D.
CF Foundation Basbaum Family Postdoctoral fellow
Reconstitution of microbial communities of CF adults

Amanda Naimie, Research Technician
Biofilm formation by Pseudomonas aeruginosa

Yun Lou, P.D., Postdoctoral fellow
Single cell analysis of biofilm formation and c-di-GMP regulation

Jarrod Smith, Ph.D., student
Cell surface adhesions required for biofilm formation