Résumé
Anaerobic Gram-negative cocci belonging to the genus
Veillonella are currently subdivided into eight species. Among them, four have been isolated either from human flora or from clinical samples during infectious processes:
Veillonella atypica,
V. dispar,
V. parvula and
V. montpellierensis. To date, the four other species have only been found in animals. In particular,
V. ratti and
V. criceti, since their characterization, have been exclusively reported from mouth and intestine of rodents. We report here for the first time a human isolate belonging to the
V. ratti–
V. criceti group recovered in mixed aerobic–anaerobic flora from a semen sample in a 24-year-old man attending the urology unit of our hospital for infertility. Identification of the isolate was based on 16S ribosomal DNA and
dnaK gene sequencing. Since then, two strains of
Veillonella sp. recovered from semen samples remained unidentified to the species level, and 16S rDNA-based phylogenetic analysis revealed that they might represent novel taxa within the genus
Veillonella. Taken together, these observations suggest that host restriction may not exist in the genus
Veillonella and that bacterial diversity remains underestimated both within this genus and in human semen.