Liofilchem® Aztreonam ATM, Antimicrobial Susceptibility Discs, 30 µg

The Liofilchem® Aztreonam (ATM) Antimicrobial Susceptibility Discs, 30 µg are high-quality, ready-to-use antibiotic discs designed for in vitro susceptibility testing of Gram-negative bacteria, particularly those producing extended-spectrum β-lactamases (ESBLs). Each disc contains 30 micrograms of Aztreonam, a monobactam antibiotic that inhibits bacterial cell wall synthesis, specifically targeting aerobic Gram-negative organisms.

These discs are used in the Kirby-Bauer disc diffusion method on Mueller-Hinton agar, following CLSI and EUCAST standards, and are widely used in clinical microbiology labs, antimicrobial surveillance programs, and hospital infection control settings.

Key Features

• Accurate 30 µg dosage per disc ensures standardized diffusion and zone sizes.
• Effective for Gram-negative pathogens, especially Enterobacteriaceae, Pseudomonas aeruginosa, and Haemophilus influenzae.
• No activity against Gram-positive or anaerobic organisms, making it a focused AST tool.
• Manufactured under ISO 9001 and ISO 13485 certifications for consistent quality.
• Aluminum blister-packed with desiccant to preserve potency and disc integrity.
• Compliant with CLSI M100 and EUCAST breakpoint guidelines.

Specifications

Use Cases

1. Detection of Susceptibility in ESBL-Producing Gram-Negative Bacteria

Aztreonam retains activity against many ESBL-producing Enterobacteriaceae, making it useful for:

• Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis AST
• Determining susceptibility in carbapenem-sparing regimens

2. Evaluation of Pseudomonas aeruginosa and Haemophilus influenzae

Used in testing P. aeruginosa and H. influenzae where Aztreonam may serve as an effective β-lactam antibiotic alternative.

3. Use in β-lactam/β-lactamase Inhibitor Combinations

Can be combined in synergy testing with Avibactam or Clavulanic acid to evaluate the impact of β-lactamase inhibition on resistance.

4. Antimicrobial Stewardship and Resistance Surveillance

Essential for building institutional antibiograms and monitoring resistance patterns to support targeted antimicrobial therapy.

Testing Procedure

1. Inoculum Preparation
   • Adjust the bacterial suspension to 0.5 McFarland standard (~1–2 × 10⁸ CFU/mL).
2. Inoculate the Agar Plate
   • Swab Mueller-Hinton agar evenly with the prepared inoculum using a sterile swab.
3. Apply the Aztreonam Disc (30 µg)
   • Place the disc firmly onto the surface using sterile forceps or an automated disc dispenser.
4. Incubation
   • Incubate at 35 ± 2 °C for 16–18 hours in ambient air.
   • Some fastidious organisms (e.g., Haemophilus influenzae) may require enriched media and CO₂ incubation.
5. Interpretation
   • Measure the diameter of the zone of inhibition in millimeters.
   • Refer to CLSI or EUCAST standards for interpretive criteria.

Interpretive Breakpoints (CLSI M100, Example)

Always consult the latest CLSI or EUCAST guidelines for updated values.

Comparison with Related Liofilchem® AST Discs

Unique Advantages of Liofilchem® Aztreonam Discs

• Precise, reliable zone measurement in detecting susceptibility among Gram-negative bacteria.
• Broad-spectrum Gram-negative coverage, including organisms with β-lactamase resistance mechanisms.
• Highly stable formulation, ideal for long-term inventory and consistent performance.
• Valuable in ESBL and AmpC detection workflows, either alone or in synergy studies.
• Global trust and regulatory compliance, aligning with CLSI and EUCAST standards.

For In Vitro Diagnostic Use Only. Not for therapeutic use.