Related Experiment Video

Updated: Jun 17, 2026

Isolation and Identification of Waterborne Antibiotic-Resistant Bacteria and Molecular Characterization of their Antibiotic Resistance Genes
08:58

Isolation and Identification of Waterborne Antibiotic-Resistant Bacteria and Molecular Characterization of their Antibiotic Resistance Genes

Published on: March 3, 2023

[On the susceptibility of AmpC-producing bacteria to third-generation cephalosporins]

Roman Jirsa1, Milan Kolár

  • 1Department of Clinical Microbiology, Regional Hospital Mladá Boleslav, Mladá Boleslav, Czech Republic. roman.jirsa@onmb.cz

Klinicka Mikrobiologie a Infekcni Lekarstvi
|January 16, 2010
PubMed

Insights

AmpC beta-lactamase producing Enterobacteriaceae pose a growing clinical challenge. Susceptibility testing requires careful interpretation, as some strains may appear susceptible despite resistance.

Area of Science:

  • Microbiology
  • Antimicrobial Resistance
  • Clinical Diagnostics

Context:

  • Enterobacteriaceae producing AmpC beta-lactamases are increasingly prevalent.
  • Mixed inducible and constitutive AmpC production presents diagnostic challenges.
  • Current EUCAST breakpoints may misinterpret resistance in these strains.

Purpose:

  • To highlight the clinical significance of Enterobacteriaceae with mixed AmpC beta-lactamase production.
  • To emphasize the need for careful interpretation of susceptibility testing results.
  • To alert clinicians about potential treatment failures despite apparent susceptibility.

Summary:

  • Enterobacteriaceae exhibiting both inducible and constitutive AmpC beta-lactamase production are of significant clinical concern.
  • Single colonies within the zone of inhibition around third-generation cephalosporin disks warrant careful consideration.
  • These strains may be classified as susceptible or intermediate-susceptible according to current EUCAST breakpoints, potentially leading to inappropriate treatment.

Impact:

  • Improved clinical decision-making for infections caused by these resistant bacteria.
  • Enhanced understanding of AmpC beta-lactamase expression and its clinical implications.
  • Potential revision of susceptibility testing guidelines to better detect resistance in Enterobacteriaceae.

More Related Videos

Testing the Role of Multicopy Plasmids in the Evolution of Antibiotic Resistance09:00

Testing the Role of Multicopy Plasmids in the Evolution of Antibiotic Resistance

Published on: May 2, 2018

Application of the Intelligent High-Throughput Antimicrobial Sensitivity Testing/Phage Screening System and Lar Index of Antimicrobial Resistance09:59

Application of the Intelligent High-Throughput Antimicrobial Sensitivity Testing/Phage Screening System and Lar Index of Antimicrobial Resistance

Published on: July 21, 2023

Related Concept Videos

Mechanism of Antibiotic Resistance in MRSA01:25

Mechanism of Antibiotic Resistance in MRSA

Antibiotic resistance in bacteria arises when microorganisms evolve the ability to withstand drugs designed to kill them or inhibit their growth, rendering once-effective treatments useless. This phenomenon, driven by genetic change and selection under antibiotic exposure, poses a profound threat to modern medicine. Mechanisms include drug-inactivating enzymes (e.g., β-lactamases), efflux pumps that eject antibiotics, mutations altering antibiotic targets, decreased drug uptake, and acquisition...
Clinical Significance of Antibiotic Resistance01:25

Clinical Significance of Antibiotic Resistance

Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One...
Development of Antibiotic Resistance01:30

Development of Antibiotic Resistance

Antibiotic resistance is a major public health concern that arises when bacteria evolve mechanisms to withstand the effects of antibiotic treatments. This resistance can be intrinsic, acquired through genetic mutations, or transferred between bacteria via horizontal gene transfer. The development of antibiotic resistance poses significant challenges in treating bacterial infections and necessitates ongoing research to develop new therapeutic strategies.Intrinsic resistance occurs when bacterial...
Antimicrobial Proteins01:23

Antimicrobial Proteins

Antimicrobial proteins are important components of the immune system. They aid the body in combating pathogens by either killing them directly or hindering their replication processes. Four main types of antimicrobial substances are interferons, the complement system, iron-binding proteins, and antimicrobial proteins.
Interferons
Interferons (IFNs) are proteins produced by lymphocytes, macrophages, and fibroblasts infected with viruses. While IFNs cannot prevent viruses from entering and...
Antibiotic Selection00:57

Antibiotic Selection

Overview
Antimicrobial Effectiveness01:28

Antimicrobial Effectiveness

The effectiveness of antimicrobial agents depends on various factors influencing their ability to eliminate microbial populations. Larger microbial populations require more time for complete eradication, emphasizing the importance of population size analysis when evaluating antimicrobial efficacy.Microbial resistance to antimicrobial agents varies significantly. Highly resilient microorganisms include endospores, gram-negative bacteria, and non-enveloped viruses, while prions are exceptionally...