Liofilchem® Optochin Test Discs

The Liofilchem® Optochin Test is a diagnostic tool for the identification of Streptococcus pneumoniae by differentiating it from other alpha-hemolytic streptococci based on their susceptibility to optochin (ethylhydrocupreine hydrochloride).

Key Features

1. High Specificity:
   • Differentiates pneumococci from other alpha-hemolytic streptococci using optochin sensitivity.
2. Ease of Use:
   • Paper discs are pre-impregnated with 5 µg of optochin for direct application on agar plates.
3. Quick Results:
   • Results are available within 18-24 hours of incubation.
4. Validated Protocol:
   • Quality control ensures reliable and consistent results.

Specifications

Kit Contents

• Discs: 2 cartridges, each containing 50 optochin-impregnated discs.
• Packaging: Individually sealed in a foil blister pack with a desiccant.

Key Characteristics

Performance

Interpretation of Results

Control Strains

Applications

1. Clinical Diagnostics:
   • Differentiates S. pneumoniae from other alpha-hemolytic streptococci in patient samples.
2. Research Laboratories:
   • Supports pneumococcal studies and epidemiological research.
3. Educational Use:
   • Demonstrates bacterial identification techniques in microbiology courses.

Usage Guidelines

Test Procedure

1. Bring the product to room temperature before use.
2. Inoculate a blood agar plate with the test organism.
3. Apply an Optochin Test disc using sterile forceps.
4. Incubate the plate at 35 ± 2°C for 18-24 hours in 5% CO₂.
5. Measure the inhibition zone diameter using a ruler or caliper.

Storage and Precautions

• Storage:
  • Store unopened cartridges at -20°C/+8°C.
  • Opened discs must be stored at 2-8°C and used within 7 days.
• Precautions:
  • For in vitro diagnostic use only.
  • Handle all specimens as potentially infectious.
  • Ensure laboratory equipment is calibrated and maintained.

Advantages

1. Accurate Differentiation:
   • Proven effectiveness in identifying S. pneumoniae.
2. Convenience:
   • Compact and pre-prepared for immediate use.
3. Cost-Effective:
   • Reduces the need for advanced molecular diagnostics.

Warnings

1. Optochin susceptibility is a presumptive test and requires confirmation via biochemical or serological testing.
2. CO₂ concentration during incubation affects results; ensure optimal conditions.
3. Occasional optochin-resistant S. pneumoniae strains may lead to false-negative results.

References

1. Public Health England (2018). Optochin Test. UK Standards for Microbiology Investigations. TP 25 Issue 4.
2. Lennette EH, Balows A, Hausler WJ, Truant JP (1980). Manual of Clinical Microbiology. 3rd ed. ASM, Washington, D.C.