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Tritrichomonas foetus: freeze-fracture cytochemistry using polymyxin B
1Laboratório de Ultra-estrutura Celular e Microscopia Eletrônica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brazil.
Abstract:
The general structure of Tritrichomonas foetus incubated in the presence of the peptide antibiotic polymyxin B, which interacts specifically with anionic phospholipids, was analyzed using transmission electron microscopy of thin sections, and freeze-fracture replicas. Polymyxin B induced morphological changes in the plasma membrane of the parasites with the formation of membrane blebs with a diameter varying from 65 nm to 1.5 micron. Freeze-fracture images of the membrane lining the blebs showed that their inner membrane half is smooth. However, membrane particles, with a density similar to that observed on the E face of the plasma membrane, were seen on the outer half of this membrane.
Insights
Polymyxin B antibiotic causes structural changes in Tritrichomonas foetus parasites. The peptide antibiotic induces membrane blebs, altering the parasite's plasma membrane structure.
Area of Science:
- Parasitology
- Microbiology
- Cell Biology
Background:
- Tritrichomonas foetus is an important protozoan parasite.
- Polymyxin B is a peptide antibiotic known to interact with anionic phospholipids.
Purpose of the Study:
- To analyze the structural changes in Tritrichomonas foetus upon incubation with polymyxin B.
- To investigate the interaction of polymyxin B with the parasite's plasma membrane.
Main Methods:
- Transmission electron microscopy of thin sections.
- Freeze-fracture replica analysis.
Main Results:
- Polymyxin B induced morphological changes in the plasma membrane, forming blebs (65 nm to 1.5 micron).
- Freeze-fracture revealed smooth inner membrane halves of blebs.
- The outer half of the bleb membrane showed particles similar to the parasite's plasma membrane.
Conclusions:
- Polymyxin B significantly alters the plasma membrane structure of Tritrichomonas foetus.
- The findings provide insights into the mechanism of polymyxin B action on protozoan parasites.