Liofilchem® Tobramycin TOB Antimicrobial Susceptibility Discs, 30 µg

Liofilchem® Tobramycin (TOB) Antimicrobial Susceptibility Discs (30 µg) are high-quality, standardized paper discs designed for in vitro antimicrobial susceptibility testing (AST) using the Kirby-Bauer disk diffusion method. Each disc is impregnated with 30 micrograms of tobramycin, an aminoglycoside antibiotic with potent bactericidal activity against aerobic Gram-negative bacilli and select Gram-positive cocci.

Tobramycin inhibits bacterial protein synthesis by irreversibly binding to the 30S ribosomal subunit, making it highly effective against Pseudomonas aeruginosa, Escherichia coli, Klebsiella spp., and Acinetobacter spp. These discs are manufactured under ISO 9001 and ISO 13485 standards, ensuring consistent performance in diagnostic and research microbiology.

Key Features

• Standardized potency: Each disc contains 30 µg of tobramycin, ensuring accurate, reproducible inhibition zone measurement.
• Broad Gram-negative coverage: Active against E. coli, Enterobacter spp., Proteus spp., Pseudomonas spp., and other clinically relevant Gram-negative pathogens.
• Clinically relevant: Frequently used in AST panels for respiratory, urinary tract, and bloodstream infections, especially in nosocomial environments.
• CLSI and EUCAST compatible: Supports zone diameter interpretation using recognized susceptibility testing guidelines.
• Sterile and shelf-stable: Supplied in sealed cartridges (50 discs) or canisters (250 discs) with desiccant to preserve potency.
• Color-coded labeling: Aids rapid identification in high-throughput testing environments.

Applications and Use Cases

1. Clinical Microbiology

• Susceptibility testing of Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii in respiratory and bloodstream infections.
• Effective AST for Enterobacteriaceae and Staphylococcus aureus in urinary tract infections.

2. Infection Control and AMR Surveillance

• Detect resistance in multidrug-resistant Gram-negative isolates.
• Track aminoglycoside resistance trends in hospital-acquired infections.

3. Veterinary and Food Microbiology

• Use in veterinary AST panels for E. coli, Pasteurella spp., and other pathogens from livestock and poultry.

4. Pharmaceutical Research

• Evaluate tobramycin activity alone or in combination therapy (e.g., β-lactams) against resistant organisms.
• Study mechanisms of aminoglycoside resistance such as efflux pumps and modifying enzymes.

Use Instructions

1. Medium: Use Mueller-Hinton Agar (MHA).
2. Inoculum Preparation: Adjust test organism suspension to 0.5 McFarland turbidity.
3. Inoculation: Swab evenly across the agar surface using a sterile swab.
4. Disc Application: Place one 30 µg Tobramycin disc onto the agar using sterile forceps or a disc dispenser.
5. Incubation:
   • Temperature: 35 ± 2 °C
   • Duration: 16–18 hours in ambient air
6. Interpretation:
   • Measure the zone of inhibition in millimeters.
   • Refer to CLSI or EUCAST interpretive criteria for categorization into Susceptible, Intermediate, or Resistant.

Technical Specifications

Quality Control

Validated with standard QC strains under CLSI/EUCAST protocols:

Liofilchem® Tobramycin TOB Discs (30 µg) are essential tools in clinical and research laboratories for detecting susceptibility to tobramycin, a key aminoglycoside used in treating life-threatening Gram-negative infections. With ISO-certified quality, reliable performance, and broad applicability in diagnostics and resistance surveillance, these discs are a trusted choice for routine antimicrobial susceptibility testing.