Rapid urease screening of Yersinia on CIN agar plates

Yersinia enterocolitica is an important foodborne pathogen, but isolation of virulent Yersinia from food sources is still time consuming and requires skills. In this article, we describe a rapid urease screening on cefsulodin–irgasan–novobiocin (CIN) agar plates with an agar overlay assay. This test is simple to perform, all colonies on a plate can be checked simultaneously, it only takes minutes for detection of urease-positive colonies and the colonies survive for transfer, further characterisation, and storage. Additionally, this method is useful to isolate virulent (urease-positive and pYV harbouring) Y. enterocolitica from foodstuffs.