Assessment of Drug Activities against Giardia Using Hyperspectral Raman Microscopy
Felicia S Manciu1,2, Jose Guerrero1, Breanna C Pence3
1Department of Physics, University of Texas at El Paso, El Paso, TX 79968, USA.
Abstract:
This study demonstrates the capability of Raman microscopy for detecting structural differences in Giardia cells exposed to different drugs and incubation times. While metronidazole (MTZ) visibly affects the cells by inducing extracellular vesicle releases of toxic iron intermediates and modified triple-bond moieties, oseltamivir (OSM) alters the phenylalanine and lipid structures. Modifications in the heme protein environment and the transformation of iron from ferric to ferrous observed for both drug treatments are more notable for MTZ. Different contents and amounts of vesicle excretion are detected for 24 h or 48 h with MTZ incubation. At a shorter drug exposure, releases of altered proteins, glycogen, and phospholipids dominate. Agglomerates of transformed iron complexes from heme proteins and multiple-bond moieties prevail at 48 h of treatment. No such vesicle releases are present in the case of OSM usage. Drug incorporations into the cells and their impact on the plasma membrane and the dynamics of lipid raft confirmed by confocal fluorescence microscopy reveal a more destructive extent by OSM, corroborating the Raman results. Raman microscopy provides a broader understanding of the multifaceted factors and mechanisms responsible for giardiasis treatment or drug resistance by enabling a label-free, simultaneous monitoring of structural changes at the cellular and molecular levels.
Insights
Raman microscopy reveals distinct cellular changes in Giardia cells treated with metronidazole (MTZ) or oseltamivir (OSM). MTZ causes iron-related vesicle release, while OSM impacts cell structure more destructively.
Area of Science:
- Biochemistry
- Cell Biology
- Microscopy
Background:
- Giardiasis remains a significant public health concern, necessitating novel therapeutic strategies.
- Understanding drug interactions at the cellular and molecular level is crucial for effective treatment and combating drug resistance.
Purpose of the Study:
- To investigate the structural and molecular changes in Giardia cells upon exposure to metronidazole (MTZ) and oseltamivir (OSM) using Raman microscopy.
- To compare the effects of different drugs and incubation times on Giardia cell structures.
Main Methods:
- Label-free Raman microscopy was employed to analyze structural modifications in Giardia cells.
- Confocal fluorescence microscopy was used to confirm drug incorporation and impact on cell membranes.
Main Results:
- Metronidazole (MTZ) induced extracellular vesicle release containing toxic iron intermediates and modified triple-bond moieties, with notable changes in heme protein environment and iron transformation.
- Oseltamivir (OSM) altered phenylalanine and lipid structures, demonstrating a more destructive impact on the plasma membrane and lipid rafts.
- Incubation time influenced vesicle content, with shorter exposures showing protein, glycogen, and phospholipid releases, while longer exposures revealed transformed iron complexes.
Conclusions:
- Raman microscopy offers a powerful tool for label-free, simultaneous monitoring of cellular and molecular changes during drug treatment.
- The study elucidates multifaceted mechanisms underlying giardiasis treatment and potential drug resistance, highlighting distinct cellular responses to MTZ and OSM.
More Related Videos
08:13A Filter-based Surface Enhanced Raman Spectroscopic Assay for Rapid Detection of Chemical Contaminants
Published on: February 19, 2016
12:08Rapid Antimicrobial Susceptibility Testing by Stimulated Raman Scattering Imaging of Deuterium Incorporation in a Single Bacterium
Published on: February 14, 2022
Related Concept Videos
01:18Drugs Affecting GI Tract Motility: Antimicrobials as Antidiarrheal Agents
01:12Giardiasis
01:15Anthelminthic Agents
01:21Antiprotozoal Agents