[New serovariants and/or antigen combinations of Listeria monocytogenes (author's transl)].

In 2111 samples of human faeces originating from 932 persons (midwives, pregnant women, slaughterhouse workers, laboratory workers, individuals with gastroenteritis and without specific symptoms) a total of 86 (9.22%) carriers of L. monocytogenes could be found. Serotyping revealed prevalence of serovar 1/2a (39%) which was characterized by beta-hemolysis and mouse pathogenicity; serovar 4b and 5, also showing beta-hemolysis and mouse pathogenicity, were met with in 11% and 2% of cases, respectively. The great proportion of non-hemolysing and apathogenic L. monocytogenes-strains (71 = 47.3%) was remarkable. They belonged to rare serovars (4a, 4ab, 4f, 4g) or, because of their O-antigen structure, could not be classified under the antigenic scheme by Donker-Voet and Seeliger. This was the case for 47 strains (approximately 31%). In these strains, O-antigen combinations V, VI, IX, XV and V, VI, IX, XIV, XV were found more frequently. With regard to epidemiology and epizootology no significance can be attributed to such strains. The question is raised whether these apathogenic and non-hemolysing serovars still should be classified among the species Listeria or whether they should be separated from this species.