Positive isolations of Yersinia obtained in repeated bacteriological examinations of porcine tongues at three slaughter-houses in Prague and a single examination at the slaughter-house at Kladno were compared with notified yersiniosis morbidity. The incidence of illnesses caused by Y. enterocolitica 03 does not exceed values of 4.5/100,000 and 3.5/100,000 population in the Czech and Slovak Socialist Republics, respectively, and is equal to a sixtieth part of the notified shigellosis and salmonellosis morbidity. Cultivation of 334 pooled samples consisting of 1142 porcine tongues yielded 12 strains (1.05%) of Y. enterocolitica 03, five strains (0.44%) of Y. pseudotuberculosis and 55 strains (4.82%) of other Yersinia organisms (indole-positive serotypes). Because of the low isolation rates obtained for the individual Yersinia species, Y. enterocolitica 03 in particular, the isolation efficiency of different cultivation techniques and culture media was statistically evaluated for all Yersinia organisms jointly. Primary cultivation on deoxycholate-citrate medium yielded five of the 12 Y. enterocolitica 03 strains isolated. The other Yersinia strains grew only after preliminary propagation. Yersinia pseudotuberculosis grew almost exclusively (4 out of 5 strains) on McConkey's agar.

Yersinia Yop-specific IgA antibodies in Hungarian blood donors