3rd Annual BMRP Investigator Meeting - Abstract

Intestinal Fungal and Bacterial Composition of the Murine Intestine

Alexandra J. Scupham¹, Laura L. Presley¹, Bo Wei², Jonathan Braun^2,a and James Borneman<sup>1

1</sup>Graduate Program in Microbiology, University of California, Riverside (Riverside, California, U.S.A.); ²Department of Pathology and Laboratory Medicine, University of California, Los Angeles (Los Angeles, California, U.S.A.)

Fungi are a diverse group of microorganisms, members of which are known to reside in commensal microbial communities of the skin and lung.  In the mammalian intestine, the extent of fungal diversity and their roles in physiological and disease processes is unstudied.  This study utilized a culture-independent method termed oligonucleotide fingerprinting of ribosomal RNA genes (OFRG) to describe the intestinal fungal and bacterial composition of mice bearing specific pathogen-free or restricted bacterial flora.  OFRG analysis identified rRNA genes from all four major fungal phyla: Ascomycota, Basidiomycota, Chytridiomycota and Zygomycota.  The largest assemblages of fungal rRNA sequences were related to the genera Acremonium, Monilinia, Fusarium, Cryptococcus/Filobasidium, Scleroderma, Catenomyces, Spizellomyces, Neocallimastix, Powellomyces, Entophlyctis, Mortierella, and Smittium and the order Mucorales.  Most of the bacterial rRNA gene clones were affiliated with three genera: Acinetobacter, Clostridium, and Lactobacillus.  Ensembles of bacterial and fungal taxa diverged in specific pathogen-free and restricted flora mice.  This report provides the first culture-independent, rRNA gene-based analysis of the fungal composition of a mammalian gut, to our knowledge.  Most of these fungi have not been previously associated with the mammalian intestine.  The diversity of the fungal community suggests unexpected roles for this component of the commensal intestinal microflora in intestinal function and host-microbial homeostasis.

^aPrincipal Investigator