0
Liofilchem® Ertapenem+Phenylboronic acid ET+BO, Antimicrobial Susceptibility Discs
Catalog No :
CAS Number :
Brand :
In Stock
Specifications:
| Application | Clinical microbiology |
| Storage Temperature | -20°C |
| Product Type | Antibiotic Disc |
| Product Brand | Liofilchem |
| Product Grade | Microbiology grade |
Liofilchem® Ertapenem+Phenylboronic Acid (ET+BO) Antimicrobial Susceptibility Discs are specialized discs used in the disk diffusion method for detecting carbapenem resistance due to AmpC beta-lactamases. This combined disc approach is designed to differentiate between carbapenem-resistant and carbapenem-sensitive strains by unmasking the presence of beta-lactamase enzymes, which degrade antibiotics such as carbapenems.
Key Features
- Dual Agent Combination: Contains 10 µg Ertapenem and Phenylboronic acid to detect AmpC beta-lactamase activity.
- Targeted Resistance Detection: Specifically designed to identify AmpC-mediated carbapenem resistance, a mechanism frequently observed in Gram-negative pathogens like Escherichia coli, Klebsiella pneumoniae, and Enterobacter spp.
- Increased Sensitivity: The addition of Phenylboronic acid helps in the inhibition of AmpC beta-lactamases, enhancing the detection of resistant organisms.
Test Procedure
- Preparation:
- Prepare a bacterial suspension using a 0.5 McFarland standard.
- Swab the bacterial suspension evenly onto Mueller-Hinton Agar plate to ensure uniform distribution.
- Placement of Discs:
- Place the ET+BO discs (10 µg Ertapenem + Phenylboronic acid) onto the inoculated agar using sterile forceps or an automated dispenser.
- Ensure that there is enough space between discs to avoid overlapping inhibition zones.
- Incubation:
- Incubate the plate aerobically at 35–37°C for 16–20 hours.
- Result Interpretation:
- After incubation, measure the diameter of the inhibition zone around the disc using a zone reader or ruler.
- Compare the zone size with the recommended breakpoints for Ertapenem resistance.
- Synergy between Ertapenem and Phenylboronic acid is indicated by an increase in the zone size of more than 5 mm compared to the zone size with Ertapenem-only discs.
- Significant Increase (>5 mm): Indicates the presence of AmpC beta-lactamase activity, suggesting carbapenem resistance.
- No Increase or Minimal Change: Likely not due to AmpC production; further testing may be required to determine other resistance mechanisms.
Control Strains and Quality Control
| Control Strain | Expected Result | Inhibition Zone (mm) |
|---|---|---|
| Escherichia coli ATCC® 25922 | No resistance | 28–32 |
| Klebsiella pneumoniae ATCC® 700603 | Resistant | 17–23 |
| Enterobacter cloacae ATCC® 13047 | AmpC positive, resistant | 22–28 |
| Pseudomonas aeruginosa ATCC® 27853 | No AmpC beta-lactamase | 18–25 |
Results Interpretation
- Sensitive Strains: If the organism is susceptible to Ertapenem, there will be a large inhibition zone with no significant increase when Phenylboronic acid is added.
- AmpC-Producing Strains: A notable increase in the inhibition zone (greater than 5 mm) when Phenylboronic acid is used alongside Ertapenem suggests that the resistance is due to AmpC beta-lactamase production.
Breakpoints (based on CLSI and EUCAST guidelines)
| Organism | Ertapenem Resistance | Interpretation |
|---|---|---|
| Enterobacteriaceae | ≥ 22 mm | Resistant |
| Pseudomonas aeruginosa | ≥ 18 mm | Susceptible |
| Acinetobacter spp. | ≥ 22 mm | Resistant/Susceptible |
The Ertapenem+Phenylboronic acid (ET+BO) disc is especially useful for the phenotypic detection of AmpC beta-lactamase in Enterobacteriaceae. It unravels the resistance in clinical strains, enabling faster decision-making regarding therapy adjustments.
Product Composition
| Component | Concentration |
|---|---|
| Ertapenem | 10 µg |
| Phenylboronic Acid | 10 µg |
| Agar | As per standard media |
Applications
- Carbapenem Resistance Screening:
- Useful in surveillance for carbapenem-resistant Enterobacterales (CRE), particularly those resistant due to AmpC beta-lactamase.
- Clinical Microbiology:
- Helps identify multidrug-resistant organisms (MDROs), guiding appropriate antimicrobial therapy.
- Antimicrobial Stewardship:
- Supports antimicrobial stewardship programs by identifying AmpC producers and informing empiric therapy decisions.
Advantages of Liofilchem® ET+BO Discs
- Rapid Detection: Provides rapid phenotypic detection of AmpC beta-lactamase-producing strains within 16–20 hours.
- Simplified Method: Offers a simple, cost-effective alternative to molecular testing.
- Routine Use: Well-suited for routine diagnostic use in clinical microbiology laboratories.
Conclusion
The Liofilchem® Ertapenem+Phenylboronic acid (ET+BO) Antimicrobial Susceptibility Discs are essential tools for detecting AmpC beta-lactamase production in Gram-negative bacteria. These discs simplify the identification of carbapenem-resistant organisms, offering reliable results that aid in infection control and antimicrobial therapy selection. Their use in combination with Mueller-Hinton agar follows established testing protocols from CLSI and EUCAST, ensuring consistent and reproducible results.