The toxin producing bacterium Clostridium difficile causes an estimated 1,000,000 to 3,000,000 cases of diarrhea and colitis in the United States each year at an annual cost of $1.1 Billion dollars for nosocomial infections alone. Most cases are associated with the administration of broad-spectrum antibiotics. It has been assumed that the administration of antibiotics causes changes in the normal gastrointestinal microbiota. These changes allow overgrowth of C. difficile, which has either been present in low numbers in the gastrointestinal tract before the administration of antibiotics, or is acquired from the environment during antibiotic administration. Furthermore, it is likely that C. difficile spores and not the vegetative bacilli are the direct contagion analogous to other pathogenic Clostridia sp. Spores are hardy, not easily cleared from the body by natural means and are resistant to antibiotics. We theorize that the normal gastrointestinal microbiota interferes with gut colonization by C. difficile and may also regulate expression of toxin by the organism. Additionally, we hypothesize that the spore morphotype itself contributes heavily to not only the initial introduction of C. difficile to the host, but also to recurrent relapse and shedding/transmission. To address these hypotheses, three specific aims are proposed for this project. In the first aim, we will compare the fecal microbiota in asymptomatically colonized individuals and patients with initial or recurrent C. difficile infection of varied severity. We will determine if specific community structures correlate with susceptibility to disease and with clinical outcomes/severity.
The second aim will extend these observations in a murine model of C. difficile infection to define the microbiologic factors that contribute to colonization resistance against C. difficile. In the third aim the contribution of germination and sporulation to clinical disease and transmission will be determined. We will characterize clinical C. difficile isolates for sporulation/germination attributes and test naturally occurring variants and defined mutants in the murine C. difficile model.
These aims will provide important insight in the roles of microbial ecology and molecular bacterial pathogenesis in C. difficile infection.
Treatment with antibiotics can lead to infection and disease with the bacterium Clostridium difficile. The proposed research will study the role ofthe existing gut bacteria and the ability ofthe pathogen to form spores in disease related to C. difficile infection. The overall goal is to increase our ability to come up with novel ways to prevent and treat this important human infection.
|Kopliku, Fatos A; Schubert, Alyxandria M; Mogle, Jill et al. (2015) Low prevalence of Clostridium septicum fecal carriage in an adult population. Anaerobe 32:34-6|
|Leslie, Jhansi L; Young, Vincent B (2015) The rest of the story: the microbiome and gastrointestinal infections. Curr Opin Microbiol 23:121-5|
|Seekatz, Anna M; Young, Vincent B (2014) Clostridium difficile and the microbiota. J Clin Invest 124:4182-9|
|Islam, J; Taylor, A L; Rao, K et al. (2014) The role of the humoral immune response to Clostridium difficile toxins A and B in susceptibility to C. difficile infection: a case-control study. Anaerobe 27:82-6|
|Rao, Krishna; Young, Vincent B; Aronoff, David M (2014) Fecal microbiota therapy: ready for prime time? Infect Control Hosp Epidemiol 35:28-30|
|Theriot, Casey M; Koenigsknecht, Mark J; Carlson Jr, Paul E et al. (2014) Antibiotic-induced shifts in the mouse gut microbiome and metabolome increase susceptibility to Clostridium difficile infection. Nat Commun 5:3114|
|El-Zaatari, Mohamad; Chang, Yu-Ming; Zhang, Min et al. (2014) Tryptophan catabolism restricts IFN-?-expressing neutrophils and Clostridium difficile immunopathology. J Immunol 193:807-16|
|Huang, A M; Marini, B L; Frame, D et al. (2014) Risk factors for recurrent Clostridium difficile infection in hematopoietic stem cell transplant recipients. Transpl Infect Dis 16:744-50|
|Schloss, Patrick D; Iverson, Kathryn D; Petrosino, Joseph F et al. (2014) The dynamics of a family's gut microbiota reveal variations on a theme. Microbiome 2:25|
|Marino, Simeone; Baxter, Nielson T; Huffnagle, Gary B et al. (2014) Mathematical modeling of primary succession of murine intestinal microbiota. Proc Natl Acad Sci U S A 111:439-44|
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