Related Experiment Video

Updated: Mar 23, 2026

A Protocol to Characterize the Morphological Changes of Clostridium difficile in Response to Antibiotic Treatment
12:58

A Protocol to Characterize the Morphological Changes of Clostridium difficile in Response to Antibiotic Treatment

Published on: May 25, 2017

9.5K

Evaluating the Effects of Surotomycin Treatment on Clostridium difficile Toxin A and B Production, Immune Response,

Bradley T Endres1, Eugénie Bassères1, Mohammed Khaleduzzaman1

  • 1University of Houston College of Pharmacy, Houston, Texas, USA.

Antimicrobial Agents and Chemotherapy
|March 30, 2016
PubMed

Insights

Surotomycin effectively reduces Clostridium difficile growth and toxin production, similar to vancomycin and metronidazole. This cyclic lipopeptide also lessens the inflammatory immune response, indicating its potential for treating C. difficile-associated diarrhea.

Area of Science:

  • Microbiology
  • Pharmacology
  • Immunology

Background:

  • Clostridium difficile-associated diarrhea (CDAD) is a significant healthcare concern.
  • Current treatments like vancomycin and metronidazole face challenges with recurrence and resistance.
  • Surotomycin, a novel cyclic lipopeptide, is under development for CDAD treatment.

Purpose of the Study:

  • To evaluate the impact of surotomycin on Clostridium difficile toxin A and B levels.
  • To assess the associated changes in immune response compared to vancomycin and metronidazole.
  • To investigate the morphological effects of surotomycin on C. difficile.

Main Methods:

  • Time-kill curve assays were conducted using C. difficile strain R20291 at various surotomycin concentrations (supra-MICs and sub-MICs).
  • Bacterial counts, toxin A and B concentrations, and cell morphology via scanning electron microscopy were analyzed.
  • Interleukin-8 (IL-8) concentrations were measured to determine inflammatory response.

Main Results:

  • Supra-MICs of surotomycin significantly reduced vegetative C. difficile cells over 72 hours (4-log difference).
  • Toxin A and B production decreased by 77% and 68% respectively, leading to reduced IL-8 concentration.
  • Morphological analysis revealed cell wall disruption at supra-MICs and a "deflated" phenotype at sub-MICs, confirming membrane activity.

Conclusions:

  • Surotomycin demonstrates potent killing effects against C. difficile.
  • It effectively reduces toxin production and attenuates the inflammatory immune response.
  • Morphological findings support surotomycin's mechanism as a membrane-active antibiotic, comparable to existing treatments.

More Related Videos

Cefoperazone-treated Mouse Model of Clinically-relevant Clostridium difficile Strain R2029106:51

Cefoperazone-treated Mouse Model of Clinically-relevant Clostridium difficile Strain R20291

Published on: December 10, 2016

13.4K
A Protein Microarray Assay for Serological Determination of Antigen-specific Antibody Responses Following Clostridium difficile Infection09:12

A Protein Microarray Assay for Serological Determination of Antigen-specific Antibody Responses Following Clostridium difficile Infection

Published on: June 15, 2018

10.5K

Related Concept Videos

Bacterial Toxins01:12

Bacterial Toxins

Bacterial toxins are sophisticated virulence factors that enable pathogenic bacteria to interact with, invade, and damage host tissues. These toxins fall broadly into two types: protein exotoxins, which are secreted into the environment and target specific host receptors, and lipopolysaccharide endotoxins, which are structural components of the bacterial outer membrane released primarily during bacterial lysis or membrane shedding. Exotoxins generally act more selectively, binding to cell...
26
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...
21
Combined Effects of Drugs: Synergism01:27

Combined Effects of Drugs: Synergism

Synergism is a useful mechanism where combining two or more drugs is more effective than each constituent used alone. Such combinations are also called supra-additive interactions. The drugs collectively enhance the final therapeutic effect by acting on different targets. Another advantage is that the low dose of each constituent drug is sufficient to achieve the desired effect. This helps reduce the duration of therapy and lower the adverse effects of these drugs.
Such synergistic combinations...
7.3K
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...
19