AUTHOR=Kim Junhyung , Guk Jae-Ho , Mun Seung-Hyun , An Jae-Uk , Kim Woohyun , Lee Soomin , Song Hyokeun , Seong Je Kyung , Suh Jun Gyo , Cho Seongbeom 

TITLE=The Wild Mouse (Micromys minutus): Reservoir of a Novel Campylobacter jejuni Strain

JOURNAL=Frontiers in Microbiology

VOLUME=10

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2019.03066

DOI=10.3389/fmicb.2019.03066

ISSN=1664-302X

ABSTRACT=<p><italic>Campylobacter jejuni</italic> is one of the most common zoonotic pathogens worldwide. Although the main sources of human <italic>C. jejuni</italic> infection are livestock, wildlife can also affect <italic>C. jejuni</italic> transmission in humans. However, it remains unclear whether wild mice harbor <italic>C. jejuni</italic> and are involved in the “environment–wildlife–livestock–human” transmission cycle of <italic>C. jejuni</italic> in humans. Here, we characterized <italic>C. jejuni</italic> from wild mice and identified genetic traces of wild mouse-derived <italic>C. jejuni</italic> in other hosts using a traditional approach, along with comparative genomics. We captured 115 wild mice (49 <italic>Mus musculus</italic> and 66 <italic>Micromys minutus</italic>) without any clinical symptoms from 22 sesame fields in Korea over 2 years. Among them, <italic>M. minutus</italic> were typically caught in remote areas of human houses and <italic>C. jejuni</italic> was solely isolated from <italic>M. minutus</italic> (42/66, 63.6%). We identified a single clone (MLST ST-8388) in all 42 <italic>C. jejuni</italic> isolates, which had not been previously reported, and all isolates had the same virulence/survival-factor profile, except for the plasmid-mediated <italic>vir</italic>B11 gene. No isolates exhibited antibiotic resistance, either in phenotypic and genetic terms. Comparative-genomic analysis and MST revealed that <italic>C. jejuni</italic> derived from <italic>M. minutus</italic> (strain SCJK2) was not genetically related to those derived from other sources (registered in the NCBI genome database and PubMLST database). Therefore, we hypothesize that <italic>C. jejuni</italic> from <italic>M. minutus</italic> is a normal component of the gut flora following adaptation to the gastro-intestinal tract. Furthermore, <italic>M. minutus</italic>-derived <italic>C. jejuni</italic> had different ancestral lineages from those derived from other sources, and there was a low chance of <italic>C. jejuni</italic> transmission from <italic>M. minutus</italic> to humans/livestock because of their habitat. In conclusion, <italic>M. minutus</italic> may be a potential reservoir for a novel <italic>C. jejuni</italic>, which is genetically different from those of other sources, but may not be involved in the transmission of <italic>C. jejuni</italic> to other hosts, including humans and livestock. This study could form the basis for further studies focused on understanding the transmission cycle of <italic>C. jejuni</italic>, as well as other zoonotic pathogens originating from wild mice.</p>