954. In Vivo Correlation Between Clostridium difficile Toxin and Spore levels in Symptomatic CDI Patients
Session: Poster Abstract Session: Clostridium difficile Infections: Epidemiology and Diagnostics
Friday, October 9, 2015
Room: Poster Hall
  • IDweek_Poster1004.pdf (572.6 kB)
  • Background: Clostridium difficile is an anaerobic, spore-forming, Gram-positive bacillus associated with a toxin-mediated intestinal disease known as Clostridium difficile infection (CDI). C.difficile is the most common etiological agent associated with antibiotic-associated diarrhea and CDI is the leading cause of healthcare-associated infections in the United States.   Fecal C.difficile toxin levels are positively correlated with CDI symptoms and disease severity, but, at least in vitro, spore production and toxin levels are negatively correlated, implying a trade-off between the two.  However, since in vivo, C.difficile interacts with other microorganisms, molecules from the host’s immune response, enzymes, nutrients, and antibiotics we hypothesized that this correlation might not hold in vivo

    Methods: We performed a cross-sectional survey of C. difficile positive samples from Saint Joseph Mercy Hospital from February 3rd, 2015 to May 12th, 2015.   We measured the amount of toxin in stool using an Enzyme Immunoassay (EIA) (Techlab: C. difficileToxA/B II). We also quantified the number of spores by culturing serial dilutions of each specimen following a heat shock. 

    Results: To date, we have screened 115 samples--82 inpatients, 30 outpatients and 3 from the Emergency Department.  Our study population was composed of 69 females (60%) and 63 patients (55%) were above 65 years of age.  In contrast to in vitro results, in vivo spore and toxin levels were positively correlated (r=0.627, p = <0.001). There is also a trend suggesting correlation of age with spore levels (r= 0.213, p= 0.022) and toxin levels(r= 0.152, p= 0.106). 

    Conclusion: Among stool samples positive for C.difficile, spore and toxin levels were positively correlated.  This suggests that resolving CDI symptoms may correspond to decreasing infectivity, and that, in vivo, there is no trade off for C.difficile between sporulation and toxin production.

    Natalia Blanco, MPH1, Anurag Malani, MD, FIDSA2, Marisa Eisenberg, PhD, MS1, Alexander Rickard, PhD, MSc, BSc1, Seth Walk, PhD3 and Betsy Foxman, PhD, FIDSA1, (1)Epidemiology, University of Michigan, Ann Arbor, MI, (2)St. Joseph Mercy Health System, Ypsilanti, MI, (3)Microbiology & Immunology, Montana State University, Bozeman, MT


    N. Blanco, None

    A. Malani, None

    M. Eisenberg, None

    A. Rickard, None

    S. Walk, None

    B. Foxman, None

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