CHROMagar™ Y. enterocolitica

Appearance of the colonies

Pathogenic  Y. enterocolitica

Mallow

Non-pathogenic Y. enterocolitica  and background flora (Citrobacter, Enterobacter, Aeromonas, etc.) 

Metallic blue, inhibited or limited growth in metallic blue.

Performance

Within the genus Yersinia, Y. enterocolitica is one of the most common foodborne pathogens. In several countries, Y. enterocolitica has eclipsed Shigella and is approaching Salmonella and Campylobacter as the leading cause of acute bacterial gastroenteritis. Its ability to grow at refrigeration temperatures makes it a growing concern in terms of food safety. This bacterium most commonly affects young people. However, only a few strains of Y. enterocolitica cause disease in humans. Pathogenic Y. enterocolitica strains belong to biotypes 1B, 2, 3, 4, and 5, whereas strains of biotype 1A are nonpathogenic and widely found in the environment. The largest animal reservoir of disease-causing Y. enterocolitica is pigs.

Application

CHROMagar™ Y.enterocolitica is a selective chromogenic culture medium intended for the direct qualitative detection, differentiation and presumptive identification of pathogenic biotypes of Yersinia enterocolitica. The test is performed on rectal swab and stool specimens to aid in the diagnosis of Y. enterocolitica infections. Results can be interpreted after 36-48 h of aerobic incubation at 30°C ± 2°C.

Concomitant culture is necessary to recover organisms for further microbiological testing or epidemiological typing. Lack of growth or absence of colonies on CHROMagar™ Y.enterocolitica does not exclude the presence of Y. enterocolitica. CHROMagar™ Y.enterocolitica is not intended to diagnose infection or to guide or monitor the treatment of infections. CHROMagar™ Y.enterocolitica may also be used in the detection of Y. enterocolitica in the analysis of food/animal products and environmental samples.

1. High specificity of the mauve color  :

Clear differentiation of Yersinia from background flora:  Background flora on CIN agar often has a red Yersinia -like appearance (such as Citrobacter ), which creates a large routine workload due to false positive results. With CHROMagar™ Y.enterocolitica, this unnecessary workload is eliminated as only pathogenic Yersinia enterocolitica colonies will grow in a mauve colour.

Colourful differentiation between  pathogenic and non-pathogenic Yersinia enterocolitica :  On traditional culture media such as CIN agar,  pathogenic and non-pathogenic biotypes appear the same. On CHROMagar™ Y.enterocolitica, pathogenic biotypes grow with a distinctive mauve colour, which can be visually differentiated from non-pathogenic biotypes, which will grow in metallic blue. 

2. High selectivity: reduction of background flora:   Background flora is drastically reduced with CHROMagar™ Y.enterocolitica, making plate reading easier. Laboratories can concentrate their efforts and resources on suspicious colonies with a real potential for pathogenicity.

Composition