P1187 - Correlations Among Fungal Species of Intestinal Mycobiome and Pathogenic Bacterial Species in Human Gut in Patients With Recurrent Clostridioides difficile Infection

Sandeep Verma, MBBS, MD, Elad Firnberg, PhD, Rakesh Vinayek, MD, FACG, Padmanabhan P. Nair, PhD, Sudhir K. Dutta, MD, FACG
Sinai Hospital of Baltimore, Baltimore, MD

Introduction: Mycobiome is a term used to describe a group of commensal fungi that are present in human gastrointestinal tract. We have recently reported alterations in fecal mycobiome in patients with recurrent clostridioides difficile infection(rCDI) (Gastroenterology 160(6) S-168, 2021). However, there is paucity of data on bacterial and fungal correlation in the microecology of human intestine. This study was designed to examine the correlation of fungal species of mycobiome and pathogenic in GI tract of patients with rCDI.

Methods: Ten patients with documented two or more C. diff infections who did not respond to antibiotics were enrolled in this study. Fecal samples were collected for these patients before and 1 month after IMT and their corresponding healthy donors. The DNA from fecal samples was isolated using the QIAGEN DNeasy PowerSoilPro kit and quantified by Qubit. Illumina Nextera XT was used for DNA libraries. The raw ITS2 amplicon metagenomic data was analyzed using UNITE database. These datasets simultaneously to examine the correlation between fungi and bacterial strains in fecal samples in patients with rCDI pre and post-IMT and their corresponding healthy donors.

Results: As many as 361 fungal species were identified with ITS2 sequence analysis and 1453 bacterial strains were also identified on deep shotgun metagenomic next generation sequence analysis. We observed positive correlation between pathogenic fungi and pathogenic bacterials strains including toxigenic clositridioides difficile strains. Some of the top correlations were Enterococcus avium ATC 14025 (bacteria) and Candida_u_s (fungi) pearson correlation coefficient (r=0.68, p< 0.0001), Escherichia coli 2-210-07_s3_c1 and Candida_u_s (r=0.68, p< 0.0001), Clostridioides difficile P28 and Candida glabrata (r=0.63, p< 0.0001), Klebsiella oxytoca BRL6-2 and Agaricales_u_s (r=0.63, p< 0.0001), Enterococcus dispar ATCC 51266 and Candida_u_s (r=0.68, p< 0.0001).

Discussion: No such correlations were observed in post-IMT cohort as well as healthy control subjects. These observations suggest unique associations in the microecology of human intestine in the patients with rCDI. We observed positive correlations among select group of pathogenic bacterial and fungal species in human intestine which is in contrast to commonly observed negative correlation among fungal and bacterial species in nature. Further studies are required to examine the complex interplay between bacterial and fungi at microecological level leading to dysbiosis.




Disclosures:


Sandeep Verma, MBBS, MD, Elad Firnberg, PhD, Rakesh Vinayek, MD, FACG, Padmanabhan P. Nair, PhD, Sudhir K. Dutta, MD, FACG. P1187 - Correlations Among Fungal Species of Intestinal Mycobiome and Pathogenic Bacterial Species in Human Gut in Patients With Recurrent Clostridioides difficile Infection, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.