Liofilchem® VCAT supplement

The V.C.A.T. Supplement is a freeze-dried selective supplement designed for the preparation of G.C. Medium (codes 610022 or 620022) to cultivate Neisseria species, such as Neisseria gonorrhoeae and Neisseria meningitidis. It is formulated with antibiotics and antifungals that selectively inhibit non-target organisms, ensuring optimal growth conditions for Neisseria spp. in clinical diagnostics and microbiological research.

Key Features

1. Purpose and Application

• Selective Cultivation:
  • Supports the growth of Neisseria gonorrhoeae and Neisseria meningitidis while inhibiting Gram-positive bacteria, Gram-negative non-Neisseria organisms, and fungi.
• Compatibility:
  • Specifically used with G.C. Medium (codes 610022 or 620022) as part of a comprehensive medium for selective isolation.

2. Composition

The V.C.A.T. Supplement contains a combination of selective agents with precise concentrations:

Each component provides specific inhibitory actions:

• Vancomycin: Suppresses Gram-positive bacteria by interfering with cell wall synthesis.
• Colistin: Inhibits non-Neisseria Gram-negative bacteria by disrupting the outer membrane.
• Amphotericin B: Targets fungi by increasing membrane permeability.
• Trimethoprim: Blocks dihydrofolate reductase, preventing bacterial folate metabolism in both Gram-positive and Gram-negative organisms.

3. Preparation Instructions

1. Reconstitution:
   • Aseptically dissolve the contents of one vial in 4 mL of a 1:1 mixture of ethyl alcohol and sterile distilled water.
   • Mix thoroughly to achieve complete dissolution.
2. Medium Preparation:
   • Add the reconstituted supplement to 500 mL of G.C. Medium autoclaved and cooled to 45–50°C.
   • Incorporate 5% defibrinated horse blood (cooked chocolate blood) and one vial of Vitalex Growth Supplement (reconstituted with 5 mL of restoring solution, code 81023).
   • Mix well and dispense the medium into Petri dishes.

4. Microbiological Quality Control

• Control Organisms:
  • Growth is validated using the following strains:

• Incubation Conditions:
  • Plates incubated at 36 ± 1°C for 48–72 hours in an atmosphere containing 5–10% CO₂.

5. Storage and Stability

• Store at 2–8°C in its original packaging to maintain stability.
• Once reconstituted, the supplement can be stored at -20°C for up to 30 days, protected from light.
• Use before the expiration date indicated on the label.

6. Safety Precautions

• Contains hazardous substances classified under directives 1999/45/CE and 2001/60/CE.
• For in vitro diagnostic use only in professional laboratory environments.
• Handle using approved aseptic and safety protocols when working with pathogenic organisms.

Kit Contents

• 10 vials of V.C.A.T. Supplement (freeze-dried).
• Instruction sheet.

Advantages

1. Selective Growth:
   • Highly effective in promoting Neisseria spp. growth while suppressing contaminants.
2. Ease of Use:
   • Pre-measured vials simplify preparation.
3. Flexibility:
   • Compatible with G.C. Medium and Vitalex Growth Supplement for optimized cultivation.
4. Reliable Results:
   • Quality control ensures consistent performance for diagnostic accuracy.

Applications

• Clinical Microbiology:
  • Diagnostics of sexually transmitted infections (STIs) caused by N. gonorrhoeae.
• Public Health:
  • Monitoring and culturing of N. meningitidis in meningitis outbreaks.
• Research:
  • Studies on Neisseria spp., including antimicrobial resistance.

Presentation

The V.C.A.T. Supplement is a reliable and essential reagent for preparing G.C. Medium for selective cultivation of Neisseria spp. Its well-defined formulation and compatibility with specific media ensure accurate, reproducible results for clinical and research applications.

Here is a tabulated comparison of the Liofilchem  V.C.A.T. Supplement and the Thermo Scientific™ Oxoid™ VCAT Selective Supplement:

• V.C.A.T. Supplement: Ideal for broader applications with G.C. Medium, including N. meningitidis, with additional inhibition via Trimethoprim.
• Thermo Scientific™ Oxoid™ VCAT: Simplifies workflow with liquid formulation and focuses specifically on N. gonorrhoeae isolation in NYC Medium.

The choice depends on the specific requirements of the laboratory and the desired medium for cultivating Neisseria spp..