Amoxicillin is a broad-spectrum beta-lactam antibiotic effective against various bacterial infections, including ear, respiratory, and urinary tract infections. In this article, we will explore and explain its mechanism of action and challenges with beta-lactamase-producing bacteria.
What is amoxicillin?
Amoxicillin is indicated for the treatment of infections caused by pathogenic bacteria. The spectrum of diseases is wide and includes infections of the ear, nose, and throat, as well as gastritis caused by Helicobacter pylori, lower respiratory and urinary tract infections, acute bacterial sinusitis, and skin and structural infections. Amoxicillin is a widely used beta-lactam antibiotic that has been approved for use in primary care in the EU through national procedures. Chemically, it is based on the basic structure of penicillin, with an additional amino group added, which leads to less antibiotic resistance. Beta-lactam antibiotics all have a four-membered lactam ring in their chemical structure.
How exactly does the substance work – Mechanism of Action of Amoxicillin?
Gram-positive bacteria have a cell wall made of a glycopeptide polymer, also called murein, see figure. This forms a large covering of cross-linked glycopeptides around the bacterial cell. The bacteria can only survive with this shell. The subunits that make up the cell wall are called peptidoglycans or glycopeptides. Amoxicillin stops peptidoglycan synthesis, i.e. it prevents the cell wall from being built by causing damage to this cross-linked layer. In gram-positive bacteria, amoxicillin penetrates the peptidoglycan layer and binds to the transpeptidase. This is the enzyme that catalyzes the reaction in which the subunits, the glycopeptides that make up the cell wall are bound to each other. When amoxicillin is present, the antibiotic’s reactive lactam ring forms peptide bonds with the murein, so that it can no longer bind to other subunits. It blocks the correct activity of the transpeptidase, which means that no further glycopeptides are cross-linked with the polymer that has already been formed. As a result, the cell wall structure of the bacteria is destroyed. When amoxicillin is used, peptidoglycan synthesis stops and damage to the peptidoglycan layer immediately occurs. As a result, the outer cell wall of the bacterial cells breaks down. The bacteria die. Amoxicillin therefore has a bactericidal effect, which means that it kills the bacteria.
Does amoxicillin kill all bacteria – part of the Mechanism of Action of Amoxicillin?
Based on a staining method named after the Danish scientist Hans Christian Gram, bacteria are divided into gram-positive and gram-negative. Differences in the structure of the cell walls lead to different Gram staining. However, both types of bacteria contain the glycopeptide polymer murein in their cell membrane as a building material. Amoxicillin therefore works on both groups. Because amoxicillin can kill many different bacteria, it is referred to as a broad-spectrum antibiotic. The spectrum of action of amoxicillin includes protection against Streptococcus species, Listeria, and Enterococcus spp. In addition, the drug is also effective against Haemophilus influenza, certain Escherichia coli strains, Actinomyces spp., Clostridium, Salmonella, and Shigella species, as well as Corynebacteria. However, there are also bacteria that produce an enzyme called beta-lactamase, which breaks down amoxicillin and renders it ineffective.
Disclaimer:
As a service to our readers, MVS Pharma GmbH publishing provides access to our library of archived content — in our blog. Please note the date of the last review or update on all articles. No content on this site should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.
MVS Pharma GmbH will soon be launching an omega-3 dietary supplement onto the European market that has been developed for the highest quality standards in terms of oxidation avoidance and therefore greatest bioavailability. In addition, in vitro studies are currently underway at the University of Ulm, in which Professor Dr. Rüdiger Groß tested a patented mouth and nose spray (Virudol) that can eliminate various flu viruses based on natural substances. In addition, MVS has a wholesale license and has specialized in sourcing much-needed medicines such as Amoxicillin, Salbutamol, etc. from India through its local branch with a focus on local quality and safety testing, compliance with international GMP regulations and the highest quality level of user security (examples of local language brochures, identical units of measurement, batch control and full tracking, etc.).