AUTHOR=Song Hyokeun , Kim Junhyung , Guk Jae-Ho , Kim Woo-Hyun , Nam Hajin , Suh Jun Gyo , Seong Je Kyung , Cho Seongbeom 

TITLE=Metagenomic Analysis of the Gut Microbiota of Wild Mice, a Newly Identified Reservoir of Campylobacter

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=10

YEAR=2021

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2020.596149

DOI=10.3389/fcimb.2020.596149

ISSN=2235-2988

ABSTRACT=<p><italic>Campylobacter</italic>, the most common etiologic agent of zoonotic gastroenteritis in humans, is present in many reservoirs including livestock animals, wildlife, soil, and water. Previously, we reported a novel <italic>Campylobacter jejuni</italic> strain SCJK02 (MLST ST-8388) from the gut of wild mice (<italic>Micromys minutus</italic>) using culture-dependent methods. However, due to fastidious growth conditions and the presence of viable but non-culturable <italic>Campylobacter</italic> spp., it is unclear whether <italic>M. minutus</italic> is a <italic>Campylobacter</italic> reservoir. This study aimed to: 1) determine the distribution and proportion of <italic>Campylobacter</italic> spp. in the gut microbiota of wild mice using culture-independent methods and 2) investigate the gut microbiota of wild mice and the relationship of <italic>Campylobacter</italic> spp. with other gut microbes. The gut microbiota of 38 wild mice captured from perilla fields in Korea and without any clinical symptoms (18 <italic>M. minutus</italic> and 20 <italic>Mus musculus</italic>) were analyzed. Metagenomic analysis showed that 77.8% (14 of 18) of the captured <italic>M. minutus</italic> harbored <italic>Campylobacter</italic> spp. (0.24–32.92%) in the gut metagenome, whereas none of the captured <italic>M. musculus</italic> carried <italic>Campylobacter</italic> spp. in their guts. Notably, 75% (6 of 8) of <italic>M. minutus</italic> determined to be <italic>Campylobacter</italic>-negative using culture-dependent methods showed a high proportion of <italic>Campylobacter</italic> through metagenome analysis. The results of metagenome analysis and the absence of clinical symptoms suggest that <italic>Campylobacter</italic> may be a component of the normal gut flora of wild <italic>M. minutus</italic>. Furthermore, linear discriminant analysis (LDA) showed that <italic>Campylobacter</italic> was the most enriched genus in the gut microbiota of <italic>M. minutus</italic> (LDA score, 5.37), whereas <italic>Lactobacillus</italic> was the most enriched genus in <italic>M. musculus</italic> (LDA score, −5.96). The differences in the presence of <italic>Campylobacter</italic> between the two species of wild mice may be attributed to the differential abundance of <italic>Campylobacter</italic> and <italic>Lactobacillus</italic> in their respective gut microbiota. In conclusion, the results indicate that wild <italic>M. minutus</italic> may serve as a potential <italic>Campylobacter</italic> reservoir. This study presents the first metagenomics analysis of the <italic>M. minutus</italic> gut microbiota to explore its possible role as an environmental <italic>Campylobacter</italic> reservoir and provides a basis for future studies using culture-independent methods to determine the role of environmental reservoirs in <italic>Campylobacter</italic> transmission.</p>