NewsDesk @bactiman63

In 2022, the Austrian National Reference Centre for Yersinia received 201 primary isolates of Yersinia spp. Of the 201 human isolates, 107 were pathogenic and 94 non-pathogenic.


Among the pathogenic isolates, 105 belonged to Yersinia enterocolitica (88 were serovar O:3; biovar 4) and two to Y. pseudotuberculosis. In 2022, the incidence rate for cases of yersiniosis as confirmed by the National Reference Centre was 1.18 per 100,000 inhabitants.

In vitro susceptibility testing of the 105 pathogenic Y. enterocolitica isolates revealed seventeen isolates with resistance to amoxicillin/clavulanic acid and three with resistance against tetracycline and one to co-trimoxazol. All Y. enterocolitica isolates were resistant to ampicillin.

The genus Yersinia belongs to the family of Enterobacterales. Yersinia are facultatively anaerobic, Gram-negative, coccobacilli bacteria. As psychrophilic germs, they can grow at temperatures between 4°C
and 42°C.

Animals are considered the main reservoir. To the genus Yersinia include 14 species, three of which species – Y. pestis (Y. pestis is not endemic in Austria), Y. pseudotuberculosis and some Biovars of Y. enterocolitica – are obligate pathogenic pathogens of human medical relevance.

Other species – Y. kristensenii, Y. bercovieri, Y. frederiksenii, Y. mollaretii, Y. intermedia, Y. aldovae, Y. rohdei, Y. ruckeri, Y. similis, Y. massiliensis and Y. aleksiciae – are only of secondary importance in human medicine.

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Enteropathogenic Yersinia (pathogenic Y. enterocolitica and Y. pseudotuberculosis) are zoonotic pathogens. The main reservoirs for Y. pseudotuberculosis are various mammals, with Y. enterocolitica the pig, whose tonsils are often colonized.

Transmission usually takes place via contaminated food (meat, dairy products, water). Since the bacteria can also multiply at 4°C (e.g. in the refrigerator), appropriate heating of the meat dishes is of preventive importance.

Direct transmission from infectious animals to humans or from humans to humans are rarely found. Transmissions by contaminated blood has been documented.