[ODP-018] High-ROS production from Enterococcus faecium causes diverse colitis in Il10--mice
Background: Recent study reported a causal link between specific bacterial strains and colitis at the strain level. However, this relationship is not fully clear.
Methods: 22 Enterococcus faecium strains derived from feces of different human subjects were inoculated into Il10-- mice, resulting in colitis that was evaluated by histology and real-time PCR analysis of cytokines. Whole-genome shotgun sequencing of DNA extracts from 22 E.faecium strains was performed. Reactive oxygen species (ROS) production from each E.faecium strain was measured.
Results: Innoculation of E.faecium from different subjects resulted in diverse level of colitis in Il10-- mice. Genotypes of 22 E.faecium strains determined by the deep sequencing were various and clustering of 22 strains based on the genotypes showed 2 major clusters in cluding inflammatory and probiotic clusters. Additionally, linear discriminant analysis clarified that lipoic acid metabolism was a significant different pathway between inflammatory and probiotic clusters. Furthermore, measurement of production of ROS in the culture of 22 E.faecium strains revealed that inflammatory strain produced more ROS than probiotic strains.
Conclusions: 22 E.faecium strains caused different level of colitis. Inflammatory cluster of the strains less abundantly had pathway of lipoic acid metabolism and produced more ROS than probiotic strains.