RT Journal Article SR Electronic(1) A1 Blanco, Natalia A1 Walk, Seth A1 Malani, Anurag N. A1 Rickard, Alexander A1 Benn, Michele A1 Eisenberg, Marisa A1 Zhang, Min A1 Foxman, BetsyYR 2018 T1 Clostridium difficile shows no trade-off between toxin and spore production within the human host JF Journal of Medical Microbiology, VO 67 IS 5 SP 631 OP 640 DO https://doi.org/10.1099/jmm.0.000719 PB Microbiology Society, SN 1473-5644, AB Purpose. This study aimed to describe the correlation between Clostridium difficile spore and toxin levels within the human host. In addition, we assessed whether overgrowth of Candida albicans modified this association. Methodology. We measured toxin, spore and Candida albicans levels among 200 successively collected stool samples that tested positive for C. difficile, and PCR ribotyped these C. difficile isolates. Analysis of variance and linear regression were used to test the association between spore and toxin levels. Kruskal–Wallis tests and t-tests were used to compare the association between spore or toxin levels and host, specimen, or pathogen characteristics. Results. C. difficile toxin and spore levels were positively associated (P<0.001); this association did not vary significantly with C. albicans overgrowth [≥5 logs of C. albicans colony-forming units (c.f.u.) g−1]. However, ribotypes 027 and 078–126 were significantly associated with higher levels of toxin and spores, and C. albicans overgrowth. Conclusion. The strong positive association observed between in vivo levels of C. difficile toxin and spores suggests that patients with more severe C. difficile infections may have increased spore production, enhancing C. difficile transmission. Although, on average, spore levels were higher in toxin-positive samples than in toxin-negative/PCR-positive samples, spores were found in almost all toxin-negative samples. The ubiquity of spore production among toxin-negative and formed stool samples emphasizes the importance of following infection prevention and control measures for all C. difficile-positive patients during their entire hospital stay., UL https://www.microbiologyresearch.org/content/journal/jmm/10.1099/jmm.0.000719