Analyzing In vitro and In vivo Growth Interactions Between Bordetella and Host Microflora Species
Open Access
Author:
Safi, Chetan Yagnesh
Area of Honors:
Biochemistry and Molecular Biology
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
Eric Thomas Harvill, Thesis Supervisor Joseph C. Reese, Thesis Honors Advisor Dr. Wendy Hanna-Rose, Faculty Reader
Keywords:
Bordetella Host Microflora
Abstract:
The host-specificity of the animal pathogen Bordetella bronchiseptica and the human pathogens Bordetella pertussis and B. parapertussis have previously been noted; however, the principles underlying this host-specificity are unclear. We hypothesize that host microflora, the endogenous microbes found on a host’s epithelial lining, could inhibit the growth of Bordetella through bacterial competition, leading to host-specificity. Using in vivo mouse experiments, it was observed that B. pertussis was more effective at colonizing mice depleted of culturable host microflora (HMF) than wild-type mice, while B. bronchiseptica was able to clear culturable HMF in mice three days post-inoculation. To study these bacterial interactions more specifically, murine and human HMF were isolated, identified, and competed against Bordetella using the in vitro techniques of cross-streaking, co-culture, and spot-plating. The results of these experiments indicate that B. pertussis and B. parapertussis can more effectively compete with human microflora than murine microflora. Conversely, B. bronchiseptica is able to inhibit the growth of several murine microflora species on agar but not in culture. These findings suggest that HMF interactions play a critical role in Bordetella infection. Once the interactions are understood more fully, commensal organisms could be used as therapeutics to prevent Bordetella colonization.
