ISOLATION AND CHARACTERIZATION OF FLEXISPIRA-RAPPINI FROM LABORATORY MICE

A bacterium with an unusual ultrastructure and possessing a fusiform p rotoplasmic cylinder, spiral periplasmic fibers, and bipolar tufts of sheathed flagella was identified in the intestinal mucosae of laborato ry mice. The organism was cultured under microaerophilic conditions an d was found to rapidly hydrolyze urea. On the basis of 16S rRNA gene s equence analysis, the organism was shown to be ''Flexispira rappini.'' ''F. rappini'' is closely related to members of the genus Helicobacte r and has been reported to be associated with human gastroenteritis an d ovine abortion. ''F. rappini'' has not previously been observed in t he gastrointestinal tracts of mice.