Liofilchem® Cefixime CFM, Antimicrobial Susceptibility Discs, 5 µg (copy)

The Liofilchem® Streptomycin S Antimicrobial Susceptibility Discs (available in 10 µg, 50 µg, and 300 µg concentrations) are diagnostic tools used for determining the susceptibility of bacterial pathogens to streptomycin, an aminoglycoside antibiotic. These discs are crucial for guiding appropriate antimicrobial therapy and monitoring resistance patterns in clinical microbiology laboratories.

Key Features

1. Active Ingredient:
   • Contain streptomycin, an aminoglycoside effective against various Gram-negative and some Gram-positive bacteria.
   • Three available concentrations:
     • 10 µg: Suitable for routine testing and low-level resistance detection.
     • 50 µg: Ideal for broader testing, including clinical isolates with varying resistance.
     • 300 µg: Designed for detecting high-level resistance.
2. Compliance with Standards:
   • Manufactured following Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines.
   • Ensures consistent and accurate results.
3. High-Quality Construction:
   • Discs are made from absorbent paper impregnated with a uniform concentration of streptomycin.
   • Sterile, individually sealed packaging to maintain potency and sterility.
4. Storage and Stability:
   • Store at 2–8°C to preserve efficacy.
   • Shelf life: Typically 24 months when stored correctly.
5. Compatibility:
   • Discs are compatible with manual or automated disc dispensers, ensuring ease of use in any laboratory setup.

Applications

1. Clinical Microbiology:
   • Determines the susceptibility of bacterial isolates to streptomycin for guiding antimicrobial therapy.
   • Commonly used for organisms like Mycobacterium tuberculosis, Yersinia pestis, Francisella tularensis, and Brucella species.
2. Resistance Monitoring:
   • Detects aminoglycoside-modifying enzymes (AMEs) that confer resistance to streptomycin.
   • Differentiates between low-level and high-level resistance mechanisms.
3. Research and Development:
   • Used in research laboratories to study bacterial resistance patterns and evaluate new antimicrobial combinations.

Testing Procedure

1. Preparation:
   • Prepare a bacterial suspension equivalent to 0.5 McFarland standard.
   • Inoculate the suspension uniformly onto Mueller-Hinton Agar plates.
2. Disc Placement:
   • Place the Streptomycin S discs (10 µg, 50 µg, or 300 µg) onto the inoculated agar using sterile forceps or a disc dispenser.
3. Incubation:
   • Incubate the plates at 35°C ± 2°C for 16–18 hours.
4. Interpretation:
   • Measure the diameter of the inhibition zone around each disc.
   • Compare the results with CLSI or EUCAST breakpoint tables to determine susceptibility.

Susceptibility Profiles

• Susceptible Bacteria:
  • Mycobacterium tuberculosis
  • Yersinia pestis
  • Escherichia coli
  • Salmonella and Shigella species
  • Francisella tularensis
• Resistance Mechanisms Detected:
  • Aminoglycoside-modifying enzymes (AMEs).
  • Alterations in ribosomal binding sites.
  • Efflux pump-mediated resistance.

Concentration-Specific Use Cases

Quality Control

• Positive Control Strains:
  • Escherichia coli ATCC® 25922: Confirms disc potency and performance.
  • Mycobacterium tuberculosis H37Rv: Validates accuracy in detecting tuberculosis susceptibility.
• Negative Control Strains:
  • Resistant strains showing no inhibition zones.

Advantages

1. Flexible Concentrations:
   • Provides comprehensive testing options for routine and specialized resistance detection.
2. Global Standards:
   • Adherence to CLSI and EUCAST guidelines ensures international compatibility.
3. High Sensitivity and Specificity:
   • Reliable for detecting both low-level and high-level streptomycin resistance.
4. User-Friendly Format:
   • Compatible with automated dispensers for high-throughput testing.

Packaging and Availability

• Packaging:
  • Available in packs of 250 discs.
• Ordering Information:
  • Contact Liofilchem or authorized distributors for regional availability and pricing.

The Liofilchem® Streptomycin S Antimicrobial Susceptibility Discs in 10 µg, 50 µg, and 300 µg concentrations are indispensable for clinical microbiology laboratories. Their precise formulation and adherence to global standards make them ideal for detecting streptomycin susceptibility, monitoring resistance patterns, and guiding effective treatment strategies.