Contact Mode Atomic Force Microscopy as a Rapid Technique for Morphological Observation and Bacterial Cell Damage...

Area of Science:

• Microscopy
• Nanotechnology
• Bacteriology

Background:

• Electron microscopy is a standard tool for cellular structure characterization but is complex and costly.
• Atomic force microscopy (AFM) provides high-resolution 3D imaging without vacuum or conductivity requirements, applicable to diverse samples.
• AFM offers angstrom- to micron-scale topography information using a probe to scan surfaces.

Purpose of the Study:

• To propose and validate atomic force microscopy (AFM) for bacterial morphology and cell damage assessment.
• To investigate the effects of nanoparticles (NPs) on bacterial cellular structures using AFM.
• To compare the utility of AFM with traditional electron microscopy for bacterial analysis.

Main Methods:

• Bacterial strains (Staphylococcus aureus, Escherichia coli, Pseudomonas hunanensis) were cultured.
• Staphylococcus aureus and Escherichia coli were incubated with varying concentrations of nanoparticles (NPs).
• Bacterial suspensions were fixed on glass supports, and images were acquired using contact AFM at multiple scales.

Main Results:

• AFM successfully visualized the distinct morphological characteristics of the bacterial strains.
• The study observed and characterized cellular damage in bacteria induced by nanoparticle exposure.
• AFM images provided clear evidence of NP-induced alterations in bacterial cell structures.

Conclusions:

• Contact AFM is a viable and cost-effective method for characterizing the morphology of fixed bacterial cells.
• AFM serves as a suitable tool for investigating the impact of nanoparticles on bacterial integrity.
• AFM presents an accessible and economical alternative to electron microscopy for bacterial studies.