Related Experiment Video

Updated: Apr 8, 2026

Quantifying the Cytotoxicity of Staphylococcus aureus Against Human Polymorphonuclear Leukocytes
12:27

Quantifying the Cytotoxicity of Staphylococcus aureus Against Human Polymorphonuclear Leukocytes

Published on: January 3, 2020

6.9K

Vancomycin minimum inhibitory concentrations and lethality in Staphylococcus aureus bacteremia

Felipe Sulla1, Daniel T Bussius1, Felipe Acquesta1

  • 1Division of Microbiology, Department of Pathology, Santa Casa School of Medicine, São Paulo, Brazil.

Germs
|June 23, 2015
PubMed
Abstract

Insights

Higher vancomycin minimum inhibitory concentrations (MICs) in Staphylococcus aureus bacteremia showed a trend toward increased patient lethality, though not statistically significant. Further research is needed to confirm this link and guide treatment.

Area of Science:

  • Infectious Diseases
  • Clinical Microbiology
  • Pharmacology

Background:

  • Increasing antibiotic resistance in Staphylococcus aureus, including penicillin and oxacillin resistance.
  • Emergence of vancomycin-intermediate and vancomycin-resistant Staphylococcus aureus isolates.
  • Previous studies suggest a correlation between higher vancomycin minimum inhibitory concentrations (MICs) and increased lethality, even within the susceptible range.

Purpose of the Study:

  • To investigate the association between vancomycin MICs and clinical outcomes in patients with Staphylococcus aureus bacteremia.
  • To compare vancomycin MICs determined by two different methods (microdilution and Etest) and their correlation with patient lethality.

Main Methods:

  • Retrospective analysis of hospitalized patients with Staphylococcus aureus bacteremia.
  • Comparison of vancomycin MICs using microdilution and Etest methods.
  • Correlation of MIC values (categorized as <2 mg/L and ≥2 mg/L) with patient lethality.

Main Results:

  • Lethality was 25% for isolates with microdilution MICs <2 mg/L and 33% for MICs ≥2 mg/L.
  • Lethality was 23% for isolates with Etest MICs <2 mg/L and 44% for MICs ≥2 mg/L.
  • A slight trend of increased lethality with higher MICs was observed, but did not reach statistical significance.

Conclusions:

  • The study indicated a potential trend between higher vancomycin MICs and increased lethality in Staphylococcus aureus bacteremia.
  • The observed difference lacked statistical significance, likely due to a small patient cohort.
  • Prospective studies are recommended to further elucidate this correlation and inform clinical antimicrobial therapy decisions.
Keywords:
S. aureussusceptibilityvancomycin

More Related Videos

Antimicrobial Synergy Testing by the Inkjet Printer-assisted Automated Checkerboard Array and the Manual Time-kill Method12:03

Antimicrobial Synergy Testing by the Inkjet Printer-assisted Automated Checkerboard Array and the Manual Time-kill Method

Published on: April 18, 2019

28.1K
A Reference Broth Microdilution Method for Dalbavancin In Vitro Susceptibility Testing of Bacteria that Grow Aerobically11:28

A Reference Broth Microdilution Method for Dalbavancin In Vitro Susceptibility Testing of Bacteria that Grow Aerobically

Published on: September 9, 2015

30.0K

Related Concept Videos

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...
43
Estimation of k and VD of Aminoglycosides01:20

Estimation of k and VD of Aminoglycosides

Aminoglycosides are a class of antibiotics used to treat various bacterial infections. Clinicians must determine the elimination rate constant (k) and volume of distribution (VD) to optimize therapeutic efficacy and minimize toxicity. The k value represents the rate at which the drug is removed from the body, and the VD reflects the degree to which the drug distributes into body tissues. Accurately estimating these parameters allows healthcare professionals to tailor drug dosing to individual...
308
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...
118
Determination of Multiple Dosing Parameters: Steady-State, Minimum and Maximum Concentrations01:15

Determination of Multiple Dosing Parameters: Steady-State, Minimum and Maximum Concentrations

Gentamicin, an aminoglycoside antibiotic, is commonly administered via intermittent intravenous infusion to treat severe infections. An intermittent one-hour infusion of gentamicin, administered at eight-hour intervals, allows for precise control of plasma drug concentrations, minimizing toxicity while ensuring therapeutic efficacy. Pharmacokinetic principles govern the dynamics of plasma concentrations and can be mathematically described using specific equations.The plasma drug concentration...
337
Pharmacodynamic Models: Overview01:27

Pharmacodynamic Models: Overview

Pharmacodynamic (PD) responses describe the interaction between a drug and its biological target, culminating in a physiological effect. These responses can be classified into different types: continuous variables, such as blood glucose levels; categorical outcomes, like survival rates; and time-to-event metrics, such as disease progression. Understanding and modeling PD responses are critical for optimizing drug efficacy and safety.PD models describe the relationship between drug concentration...
96
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...
56