[Occurrence of Yersinia enterocolitica, particularly serovar 03, biovar 4 in pork and beef]

The paper deals with the incidence of Yersiniae in pork and beef, focused in particular on the prevalence of Yersinia enterocolitica, serovar 3, biovar 4. The author uses for detection the method of cold shock, alkalization of the sample, taking advantage of the tolerance of Yersinias of diluted alkalis and suppressing the contaminating microflora, and the the selective medium CIN agar with a locally manufactured supplement. Cultivation was either direct or after propagation in phosphate buffer pH 7.6. The authors isolated 84 strains of Yersinias, i.e. 60% of the total number of examined specimens. Four strains were Yersinia enterocolitica, serovar 03, biovar 4 from pork by direct cultivation. Twenty strains did not agglutinate with commercial serum O-Yersinia IMUNA; they were included in the group "Yersinia enterocolitica other biovars" and 60 strains were "Environmental Yersinia isolates". The author proved a seasonal incidence of Yersinie enterocolitica, serovar 03, biovar 4. The applied method of detection and the the selective medium CIN agar with supplement proved suitable. It is important to respect hygienic provisions during processing in the slaughterhouse with regard to the high incidence of environmental Yersinias and the possible incidence of pathogenic serovars of Yersinias.