Related Experiment Video

Updated: Jun 21, 2026

Use of Artificial Sputum Medium to Test Antibiotic Efficacy Against Pseudomonas aeruginosa in Conditions More Relevant to the Cystic Fibrosis Lung
07:46

Use of Artificial Sputum Medium to Test Antibiotic Efficacy Against Pseudomonas aeruginosa in Conditions More Relevant to the Cystic Fibrosis Lung

Published on: June 5, 2012

Cerebrospinal fluid impairs antimicrobial activity of fosfomycin in vitro

Robert Sauermann1, Richard Schwameis, Manfred Fille

  • 1Department of Clinical Pharmacology, Section of Molecular Pharmacokinetics and Imaging, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria. robert.sauermann@meduniwien.ac.at

The Journal of Antimicrobial Chemotherapy
|July 23, 2009
PubMed
Abstract

Insights

Fosfomycin

Area of Science:

  • Pharmacology
  • Infectious Diseases
  • Microbiology

Background:

  • Fosfomycin demonstrates good penetration into cerebrospinal fluid (CSF), making it a candidate for treating central nervous system (CNS) infections.
  • Understanding the drug's activity within the CNS environment is crucial for effective treatment.

Purpose of the Study:

  • To evaluate how human cerebrospinal fluid (CSF) affects the antimicrobial efficacy of fosfomycin.
  • To compare fosfomycin's activity in CSF versus standard laboratory media.

Main Methods:

  • Time-kill kinetics were assessed for Staphylococcus aureus in Mueller-Hinton broth (MHB) and human CSF across various fosfomycin concentrations (0.25x to 8x MIC).
  • In vitro simulations replicated a patient's in vivo CSF pharmacokinetic profile to assess bacterial response.

Main Results:

  • Higher fosfomycin concentrations (8x MIC) were needed for sustained bacterial killing in CSF compared to MHB (1x MIC).
  • Simulated CSF drug concentrations led to initial bacterial killing but were followed by bacterial regrowth, indicating insufficient sustained activity.

Conclusions:

  • Fosfomycin exhibits reduced antimicrobial activity in human CSF compared to standard MHB.
  • Fosfomycin doses that only slightly exceed the minimum inhibitory concentration (MIC) may be inadequate for achieving bactericidal effects in CNS infections.

More Related Videos

Development of a Polymicrobial Colony Biofilm Model to Test Antimicrobials in Cystic Fibrosis07:16

Development of a Polymicrobial Colony Biofilm Model to Test Antimicrobials in Cystic Fibrosis

Published on: September 20, 2024

Antibiotic Efficacy Testing in an Ex vivo Model of Pseudomonas aeruginosa and Staphylococcus aureus Biofilms in the Cystic Fibrosis Lung09:26

Antibiotic Efficacy Testing in an Ex vivo Model of Pseudomonas aeruginosa and Staphylococcus aureus Biofilms in the Cystic Fibrosis Lung

Published on: January 22, 2021

Related Concept Videos

Inhibitors of Bacterial Protein Synthesis01:25

Inhibitors of Bacterial Protein Synthesis

Aminoglycosides constitute a highly potent class of bactericidal antibiotics that exert their antimicrobial effects by targeting the bacterial ribosome, specifically disrupting protein synthesis. These polycationic molecules consist of amino-modified sugars linked via glycosidic bonds to an aminocyclitol core such as 2-deoxystreptamine or streptamine. Their strong positive charges facilitate tight binding to the negatively charged phosphate backbone of ribosomal RNA (rRNA), primarily at the 16S...
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...
Inhibitors of Bacterial DNA Synthesis01:28

Inhibitors of Bacterial DNA Synthesis

Bacterial pathogens depend on precise and efficient DNA replication to sustain infection. Two type II topoisomerases—DNA gyrase and topoisomerase IV—are critical to this process, as they resolve DNA supercoiling and unlink chromosomes during replication. Fluoroquinolones, synthetic derivatives of quinolones, exploit this mechanism by stabilizing the transient DNA–enzyme cleavage complex, preventing strand religation, and causing lethal double-strand breaks. These antibiotics are selectively...
Cryptococcal Meningitis01:27

Cryptococcal Meningitis

Cryptococcal meningitis is a life-threatening opportunistic infection predominantly associated with HIV/AIDS, accounting for over 100,000 deaths annually worldwide. However, it also affects individuals with other forms of immunosuppression, including those undergoing immunosuppressive therapy, organ transplant recipients, patients with innate immunodeficiencies, and individuals with hematological disorders. The infection is caused mainly by Cryptococcus neoformans and Cryptococcus gattii,...
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...
Antifungal Agents01:15

Antifungal Agents

Amphotericin B is a broad-spectrum antifungal agent that exploits structural differences between fungal and mammalian cell membranes. Its amphipathic structure—featuring a hydrophobic polyene-lactone ring and a hydrophilic region containing mycosamine and carboxylic acid groups—enables selective binding to ergosterol, a sterol predominantly found in fungal plasma membranes. This selective interaction underlies the drug’s antifungal activity, although weak binding to cholesterol contributes to...