Liofilchem Yersinia Selective supplement

Yersinia Supplement is a selective additive used in the preparation of Yersinia Selective Agar Base (ref. 610111, 620111) for isolating Yersinia enterocolitica from clinical and non-clinical specimens. It contains a blend of antibiotics to inhibit competing Gram-negative and Gram-positive bacteria while allowing Yersinia growth.

Kit Contents

• 10 vials of freeze-dried Yersinia Supplement.
• 1 instruction sheet detailing preparation and usage.

Composition

The supplement contains the following antibiotics per vial and per liter of medium:

These antibiotics inhibit most Gram-negative enteric bacteria and other unwanted flora.

Preparation Procedure

1. Reconstitution:
   • Dissolve the contents of one vial in 2 ml of sterile distilled water and 1 ml ethanol (50% purity minimum).
   • Mix thoroughly until fully dissolved.
2. Addition to Agar Base:
   • Add the reconstituted supplement to 500 ml of Yersinia Selective Agar Base (previously autoclaved and cooled to 45–50°C).
   • Mix well and pour the medium into Petri dishes.

Quality Control

1. Physical Appearance:
   • Freeze-dried supplement should appear white in color.
2. Microbiological Performance:
   • Test using the following control strains:
     • Yersinia enterocolitica (WDCM 00038): Good growth.
     • Escherichia coli (WDCM 00012): Partially to totally inhibited.
     • Staphylococcus aureus (WDCM 00034): Inhibited.
   • Incubate plates at 30 ± 1°C for 18-24 hours.

Storage Instructions

• Store at 2–8°C in the original packaging.
• Reconstituted supplement can be stored for up to 30 days at -20°C, protected from light.
• Do not use beyond the expiry date or if signs of deterioration are observed.

Precautions

• Classified as hazardous; refer to the Safety Data Sheet for proper handling.
• Intended for in vitro diagnostic use only in a professional laboratory environment.
• Handle using approved aseptic and safety methods for dealing with pathogenic agents.

References

1. EN ISO 11133:2014 – Microbiology of food, animal feed, and water: Preparation, production, storage, and performance testing of culture media.
2. ISO 10273:2003 – Detection of presumptive pathogenic Yersinia enterocolitica.
3. Schieman, D.A. (1979): Synthesis of a selective agar medium for Yersinia enterocolitica. Can. J. Microbiol., 25:1298-1304.
4. Devenish, J.A., and Schieman, D.A. (1981): Abbreviated scheme for identification of Yersinia enterocolitica on CIN agar. Can. J. Microbiol., 27:937-941.

Presentation

• One vial is sufficient to prepare 500 ml of medium.