Liofilchem® Sulbactam SU, Antimicrobial Susceptibility Discs, 20 µg

Liofilchem® Sulbactam (SU) Antimicrobial Susceptibility Discs (20 µg) are high-precision, ready-to-use paper discs impregnated with 20 micrograms of sulbactam, a β-lactamase inhibitor used to evaluate bacterial susceptibility and β-lactamase-mediated resistance mechanisms. These discs are designed for in vitro antimicrobial susceptibility testing (AST) using the Kirby-Bauer disk diffusion method, primarily in combination with β-lactam antibiotics such as ampicillin and cefoperazone.

Sulbactam alone exhibits limited intrinsic antibacterial activity but plays a critical role in enhancing the activity of β-lactam antibiotics against β-lactamase-producing organisms. Liofilchem® discs are manufactured under ISO 9001 and ISO 13485 certified quality systems, ensuring consistent potency and reproducible results.

Key Features

• Standardized dosage: Each disc contains 20 µg of sulbactam, enabling accurate and consistent inhibition zone measurements in AST procedures.
• Designed for β-lactamase resistance studies: Primarily used to assess the synergistic effect of sulbactam in combination with β-lactams (e.g., ampicillin, cefoperazone).
• Targeted activity: Effective for Escherichia coli, Klebsiella spp., Acinetobacter baumannii, and other β-lactamase-producing Gram-negative bacilli.
• Research and surveillance utility: Valuable in screening for AmpC and ESBL-producing isolates and assessing intrinsic sulbactam activity (notably against A. baumannii).
• CLSI/EUCAST-aligned testing: Compatible with zone diameter interpretive criteria when used in combination with β-lactams.
• Sterile and shelf-stable: Packaged in sealed cartridges or canisters with desiccant to preserve potency and prevent degradation.
• Color-coded labeling: Ensures fast and reliable identification in multi-disc workflows.

Applications and Use Cases

1. Clinical Microbiology

• Evaluate synergistic effects of sulbactam when combined with ampicillin or cefoperazone.
• Detect β-lactamase-producing Gram-negative bacteria in urinary, respiratory, and bloodstream infections.
• Direct susceptibility testing for Acinetobacter baumannii, where sulbactam may have independent antibacterial activity.

2. Infection Control & Surveillance

• Monitor resistance trends in nosocomial Gram-negative isolates.
• Investigate resistance mechanisms and inhibitor activity against extended-spectrum β-lactamases (ESBLs) and AmpC enzymes.

3. Pharmaceutical Research

• Study pharmacodynamic interactions and β-lactamase inhibition profiles.
• Support antimicrobial development and clinical efficacy studies.

Use Instructions

1. Media: Mueller-Hinton Agar (MHA) is recommended for standard susceptibility testing.
2. Inoculum Preparation: Adjust bacterial suspension to 0.5 McFarland turbidity standard.
3. Inoculation: Evenly swab the standardized inoculum over the agar surface.
4. Disc Placement: Place a 20 µg Sulbactam disc on the agar surface using sterile forceps or a disc dispenser.
   May also be used adjacent to ampicillin or cefoperazone discs for synergy zone analysis.
5. Incubation:
   • Temperature: 35 ± 2 °C
   • Time: 16–18 hours, aerobic conditions
6. Interpretation:
   • Measure the diameter of the zone of inhibition (mm).
   • Interpret based on internal laboratory standards or in combination with partner β-lactams per CLSI/EUCAST guidance.

Technical Specifications

Quality Control

Validated using CLSI/EUCAST quality control organisms:

Liofilchem® Sulbactam SU Discs (20 µg) provide a precise and reliable means of testing β-lactamase inhibition and sulbactam efficacy in combination with partner antibiotics. Ideal for detecting resistance mechanisms and evaluating treatment options in challenging Gram-negative infections, these discs are essential for both diagnostic laboratories and research environments committed to tackling antimicrobial resistance.