Sabine Hazan, Sonya Dave , Andreas Papoutsis, Brad D. Barrows, Brad D. Barrows ,Thomas J. Borody
Introduction: Toxigenic Clostridioides Difficile Infection (CDI) is the most common cause of nosocomial disease in the United States. However, the prevalence in the general population of toxigenic and non-toxigenic strains is poorly understood. In this cross-sectional study we sought to determine the presence of Clostridioides difficile colonizing a representative sample of 119 CDI-asymptomatic volunteers (health care providers, public with chronic conditions,
and healthy public).Materials and Methods: Next Generation Sequencing (NGS) was performed on fecal samples from participants (n=119) who clinically did not have CDI. Following stool collection, DNA was extracted, quantitated, and then normalized for downstream library fabrication utilizing shotgun methodology. Prepared and indexed libraries were subsequently pooled and sequenced on the Illumina Next Seq 550 System. Results: 117 of the 119 subjects (98%) were found to possess C. difficile as identified by the Kraken bioinformatics meta genomic pipeline. The C. difficile normalized count was independent of health care setting exposure, age,probiotic use, or health history.Conclusion: NGS provides a unique opportunity to increase the resolution and identification of the bacterium C.difficile compared to traditional categorizations. Using meta-genomics and a stringent read count criteria (>1000 counts), we deciphered species level resolution of bacteria present, finding C. difficile in 98% of subjects, which arelikely non-toxigenic. This discovery suggests that non-pathogenic C. difficile may be an important component of the human commensal gut microbiome, possibly present since birth. This raises fundamental questions regarding assumptions of CDI transmission that need future exploration. Given that non-pathogenic C. difficile has been used for CDI treatment, determining levels of non-pathogenic C. difficile in stool may be predictive of resistance to development of CDI.