EN
A case of listeriosis in new-born foxes has been described. At necropsy a significant enlargement of the spleen was observed, from which a pathogen was isolated in a pure culture. On agar medium with sheep blood (5 per cent), tiny colonies with a wide zone of beta-haemolysis were noticed after 24 hours growth. On microscopic films gram-positive rods measuring 2 by 0.5 |im were found. The rods were distinctively mobile at 22°C. They produced catalase, fermented aesculine, d-arabitol, rhamnose, alp- ha-methyl-D-glucoside and alpha-xylose. D-xylose, glucose- -1-phosphate, D-tagose and alpha-mannosidase were not fermented. The strains proved to be pathogenic for mice and guinea-pigs. A severe conjunctivitis was observed in guinea-pigs which were administered a suspension of the bacteria intraconjunctively. In the exudation, grampositive rods were found (Anton’s test - positive). The examinations allowed the classification of the isolated bacteria as Listeria monocytogenes.