[Isolation of Listeria ivanovii in Slovakia].

From October 1977 to May 15, 1989 in Slovakia 39 strongly haemolytic strains of L. ivanovii were isolated from a woman after delivery of a stillborn foetus--from the lochiae, placenta and rectal smear, from five symptom-free subjects from the faeces, from the rectal smears of two sheep, from the intestinal contents in the portion of the terminal ileus from 28 free living small terrestrial mammals, one strain from meat--beef steak, from the lungs, liver and kidneys of a dead young sheep and one strain from silage. The strains from the lochiae and placenta as well as those from the organs of sheep were detected already as primocultures on commonly used blood agar, the other strains after varying periods of cold enrichment and subsequent inoculation on a solid selective medium with nalidixic acid and acriflavin.

Hemolytic phenomenons under the cultivation of Listeria innocua.

It was proved that Listeria innocua is able to hemolyze rabbit erythrocytes in blood agars when Oxoid or Difco nutrient agars are used as basic substrate. After 48 h incubation at 37 degrees C and a further 24 h at 4 degrees C the hemolytic effect was clearly expressed. The hot-cold incubation was inevitable.

Routine test for in vitro differentiation of pathogenic and apathogenic Listeria monocytogenes strains.

The exosubstance of Rhodococcus equi in a prepurified form strongly enhanced the hemolytic effect of certain strains of Listeria monocytogenes. The strains which produced positive synergic hemolysis with this exosubstance were also pathogenic for guinea pigs and white mice. The other strains, which remained nonhemolytic in the presence of the R.