Inhibition of Gram-Negative Cystic Fibrosis Pathogens by Stenotrophomonas maltophilia in Co-culture Biofilms
Grade Level at Time of Presentation
Senior
Major
Biology & Psychology
Institution
University of Louisville
KY House District #
59
KY Senate District #
26
Faculty Advisor/ Mentor
Dr. Deborah Yoder-Himes
Department
Department of Biology
Abstract
Inhibition of Gram-Negative Cystic Fibrosis Pathogens by Stenotrophomonas maltophilia in Co-culture Biofilms
Joshua Stewart, Deborah Yoder-Himes, Ph.D.
University of Louisville, Department of Biology
Cystic Fibrosis (CF) is one of the most common lethal genetic disorders in the Caucasian population with an incidence of 1 per 3,000 live births and a median predicted survival of only 47 years. Respiratory failure due to repeated pathological insults to lung tissue by infection is the ultimate cause of mortality in the majority of patients. The lung microenvironment created by CF highly favors colonization by opportunistic pathogens like Pseudomonas aeruginosa, Staphylococcus aureus, Stenotrophomonas maltophilia, Achromobacter xylosoxidans, and Burkholderia cenocepacia. Biofilm formation by multiple bacterial species contributes to the chronic, persistent, and difficult to treat nature of CF infections. This study seeks to further our limited understanding of what polymicrobial biofilm interactions may be occurring in the CF lung. Survival assays of bacterial cells grown in biofilm-forming conditions demonstrated that no detectable growth occurred for B. cenocepacia or A. xylosoxidans in co-culture with S. maltophilia. Further experimentation including supernatant screens, treatment with cell-lysate, pH measurements, and laser scanning confocal microscopy have elucidated further hints about the mechanisms of this S. maltophilia-mediated inhibition. Characterization of these interspecies relationships may further our understanding of how flora composition influences pathogenesis in the CF lung and has the potential to influence therapeutic approaches.
Inhibition of Gram-Negative Cystic Fibrosis Pathogens by Stenotrophomonas maltophilia in Co-culture Biofilms
Inhibition of Gram-Negative Cystic Fibrosis Pathogens by Stenotrophomonas maltophilia in Co-culture Biofilms
Joshua Stewart, Deborah Yoder-Himes, Ph.D.
University of Louisville, Department of Biology
Cystic Fibrosis (CF) is one of the most common lethal genetic disorders in the Caucasian population with an incidence of 1 per 3,000 live births and a median predicted survival of only 47 years. Respiratory failure due to repeated pathological insults to lung tissue by infection is the ultimate cause of mortality in the majority of patients. The lung microenvironment created by CF highly favors colonization by opportunistic pathogens like Pseudomonas aeruginosa, Staphylococcus aureus, Stenotrophomonas maltophilia, Achromobacter xylosoxidans, and Burkholderia cenocepacia. Biofilm formation by multiple bacterial species contributes to the chronic, persistent, and difficult to treat nature of CF infections. This study seeks to further our limited understanding of what polymicrobial biofilm interactions may be occurring in the CF lung. Survival assays of bacterial cells grown in biofilm-forming conditions demonstrated that no detectable growth occurred for B. cenocepacia or A. xylosoxidans in co-culture with S. maltophilia. Further experimentation including supernatant screens, treatment with cell-lysate, pH measurements, and laser scanning confocal microscopy have elucidated further hints about the mechanisms of this S. maltophilia-mediated inhibition. Characterization of these interspecies relationships may further our understanding of how flora composition influences pathogenesis in the CF lung and has the potential to influence therapeutic approaches.