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Updated: Oct 23, 2025
Visualizing Membrane Ruffle Formation using Scanning Electron Microscopy
Published on: May 27, 2021
Investigation of morphological changes of HPS membrane caused by cecropin B through scanning electron microscopy and
Han Hu1,2, Changsheng Jiang2, Binzhou Zhang2
1National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, Hubei 430068, China.
Background:
Antimicrobial peptides (AMPs) have been identified as promising compounds for consideration as novel antimicrobial agents.
Objectives:
This study analyzed the efficacy of cecropin B against Haemophilus parasuis isolates through scanning electron microscopy (SEM) and atomic force microscopy (AFM) experiments.
Results:
Cecropin B exhibited broad inhibition activity against 15 standard Haemophilus parasuis (HPS) strains and 5 of the clinical isolates had minimum inhibition concentrations (MICs) ranging from 2 to 16 μg/mL. Microelectrophoresis and hexadecane adsorption assays indicated that the more hydrophobic and the higher the isoelectric point (IEP) of the strain, the more sensitive it was to cecropin B. Through SEM, multiple blisters of various shapes and dents on the cell surface were observed. Protrusions and leakage were detected by AFM.
Conclusions:
Based on the results, cecropin B could inhibit HPS via a pore-forming mechanism by interacting with the cytoplasmic membrane of bacteria. Moreover, as cecropin B concentration increased, the bacteria membrane was more seriously damaged. Thus, cecropin B could be developed as an effective anti-HPS agent for use in clinical applications.
Insights
Cecropin B effectively inhibits Haemophilus parasuis (HPS) by damaging bacterial membranes. This antimicrobial peptide shows potential as a novel therapeutic agent against HPS infections.
Area of Science:
- Microbiology
- Biochemistry
- Veterinary Medicine
Background:
- Antimicrobial peptides (AMPs) are promising candidates for novel antimicrobial agents.
- Haemophilus parasuis (HPS) is a significant pathogen in swine, necessitating new treatment strategies.
Purpose of the Study:
- To evaluate the efficacy of cecropin B against Haemophilus parasuis (HPS) isolates.
- To investigate the mechanism of action of cecropin B on HPS using advanced microscopy techniques.
Main Methods:
- Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) were employed to visualize bacterial surface changes.
- Minimum Inhibition Concentrations (MICs) were determined for various HPS strains.
- Microelectrophoresis and hexadecane adsorption assays assessed bacterial surface properties.
Main Results:
- Cecropin B demonstrated broad-spectrum activity against 15 standard HPS strains, with MICs ranging from 2 to 16 μg/mL for clinical isolates.
- Bacterial sensitivity to cecropin B correlated with hydrophobicity and isoelectric point (IEP).
- SEM revealed cell surface blisters and dents, while AFM detected protrusions and leakage, indicating membrane damage.
Conclusions:
- Cecropin B inhibits HPS through a pore-forming mechanism, targeting the bacterial cytoplasmic membrane.
- Increased cecropin B concentration leads to more severe bacterial membrane damage.
- Cecropin B holds potential for development as a clinical anti-HPS agent.
