Résumé:
Bartonelloses are neglected emerging infectious diseases caused by facultatively
intracellular bacteria transmitted between vertebrate hosts by various arthropod
vectors. The highest diversity of Bartonella species has been identified in rodents.
Within this study we focused on the edible dormouse (Glis glis), a rodent with
unique life-history traits that often enters households and whose possible role
in the epidemiology of Bartonella infections had been previously unknown.
We identified and cultivated two distinct Bartonella sub(species) significantly
diverging from previously described species, which were characterized using
growth characteristics, biochemical tests, and various molecular techniques
including also proteomics. Two novel (sub)species were described: Bartonella
grahamii subsp. shimonis subsp. nov. and Bartonella gliris sp. nov. We sequenced
two individual strains per each described (sub)species. During exploratory
genomic analyses comparing two genotypes ultimately belonging to the same
species, both factually and most importantly even spatiotemporally, we noticed
unexpectedly significant structural variation between them. We found that most of
the detected structural variants could be explained either by prophage excision or
integration. Based on a detailed study of one such event, we argue that prophage
deletion represents the most probable explanation of the observed phenomena.
Moreover, in one strain of Bartonella grahamii subsp. shimonis subsp. nov.
we identified a deletion related to Bartonella Adhesin A, a major pathogenicity
factor that modulates bacteria-host interactions. Altogether, our results suggest
that even a limited number of passages induced sufficient selective pressure to
promote significant changes at the level of the genome.
