Liofilchem® Cefotaxime+Clavulanic Acid CTL Antimicrobial Susceptibility Discs, 40 µg

The Liofilchem® Cefotaxime + Clavulanic Acid (CTX+CTL) Antimicrobial Susceptibility Discs (40 µg) are specialized diagnostic tools designed for in vitro antimicrobial susceptibility testing of bacterial isolates. These discs combine the broad-spectrum third-generation cephalosporin Cefotaxime (30 µg) with the beta-lactamase inhibitor Clavulanic Acid (10 µg), enabling effective screening and confirmation of extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales and other Gram-negative bacteria.

Composition

Each disc contains:

• Cefotaxime (CTX): 30 µg
• Clavulanic Acid (CTL): 10 µg
• Total combined antibiotic content: 40 µg

Mechanism of Action

• Cefotaxime: A third-generation cephalosporin that inhibits bacterial cell-wall synthesis by binding to penicillin-binding proteins (PBPs), exerting bactericidal activity against a broad spectrum of Gram-negative organisms.
• Clavulanic Acid: A potent beta-lactamase inhibitor that protects cefotaxime from enzymatic degradation by bacterial beta-lactamases, including ESBL enzymes, restoring antibiotic susceptibility.

The synergistic action of these two agents facilitates the detection of bacteria producing beta-lactamases, which are key antibiotic resistance mechanisms.

Clinical and Laboratory Applications

1. ESBL Detection in Clinical Isolates

Primary Use:

• Screening and confirmation of Extended-Spectrum Beta-Lactamase (ESBL) production in clinical isolates of Gram-negative bacteria, including:
  • Escherichia coli
  • Klebsiella pneumoniae
  • Proteus mirabilis
  • Other Enterobacterales

Practical Example:

A clinical microbiology laboratory processes a urine sample from a patient with suspected urinary tract infection (UTI), showing resistance to third-generation cephalosporins. Using Liofilchem® Cefotaxime + Clavulanic Acid discs, the lab detects an increased inhibition zone diameter in the presence of clavulanic acid, confirming ESBL production and guiding appropriate antibiotic therapy selection.

2. Surveillance and Infection Control

Primary Use:

• Surveillance and epidemiological monitoring of multidrug-resistant (MDR) bacterial strains in:
  • Hospital settings (e.g., ICUs, surgical wards, neonatal units)
  • Long-term care facilities
  • Public health programs

Practical Example:

A hospital infection control unit routinely screens bacterial isolates from high-risk wards using these susceptibility discs to detect and monitor ESBL outbreaks, enabling rapid intervention and infection control measures.

3. Research and Antibiotic Resistance Studies

Primary Use:

• Supporting antimicrobial resistance (AMR) surveillance programs.
• Evaluating the efficacy of novel antibiotic combinations.
• Tracking ESBL prevalence and resistance patterns for public health initiatives.

Practical Example:

An academic research team utilizes Liofilchem® CTX+CTL discs in a regional antimicrobial surveillance study, providing critical epidemiological data for developing antibiotic stewardship policies.

Testing Procedure & Interpretation

1. Standardized Testing Protocol

• Use the Kirby-Bauer disc diffusion method following:
  • Clinical and Laboratory Standards Institute (CLSI) guidelines
  • European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines
• Step-by-step procedure:
  1. Prepare Mueller-Hinton agar plates inoculated with bacterial suspensions adjusted to 0.5 McFarland standard.
  2. Place CTX+CTL discs on the agar surface.
  3. Incubate at 35 ± 2°C for 16–18 hours.
  4. Measure zone diameters around discs.

2. Interpretation of Results

• Compare the inhibition zone diameters of:
  • Cefotaxime alone vs. Cefotaxime + Clavulanic Acid.
• An increase in zone diameter of ≥5 mm in the presence of clavulanic acid confirms ESBL production.

Key Benefits & Advantages

✅ Accurate & Reliable – Ensures precise detection and differentiation of ESBL-producing bacteria.

✅ Clinically Relevant – Assists in antibiotic therapy decisions and supports infection control efforts.

✅ Easy-to-Use & Standardized – Compatible with CLSI and EUCAST guidelines, facilitating seamless laboratory workflows.

✅ High Stability – Maintains consistent performance under recommended storage conditions.

Packaging & Storage

Intended Users

🔬 Clinical microbiologists

🏥 Hospital & diagnostic laboratories

🦠 Public health & epidemiology laboratories

📊 Research institutions studying antimicrobial resistance

The Liofilchem® Cefotaxime + Clavulanic Acid (CTX+CTL) Antimicrobial Susceptibility Discs (40 µg) provide essential diagnostic capabilities for timely detection of ESBL-producing bacteria, supporting infection control, surveillance, and antimicrobial resistance research.

By offering high specificity, ease of use, and compliance with global testing standards, these susceptibility discs are a reliable tool for clinical microbiology laboratories to enhance patient care and contribute to robust antimicrobial stewardship programs.