Open Access

REVIEW

Tritrichomonas foetus: New structures by high-resolution scanning helium ion microscopy

MARLENE BENCHIMOL^1,3,*, ABIGAIL MIRANDA-MAGALHÃES², ANTONIO PEREIRA-NEVES², WANDERLEY DE SOUZA³

1 Universidade do Grande Rio, Duque de Caxias, 25071-202, Rio de Janeiro
2 Departamento de Microbiologia, Laboratório de Biologia Celular de Patógenos, Fiocruz, Instituto Aggeu Magalhães, Recife, 52060-269, Brazil
3 Universidade Federal do Rio de Janeiro, Instituto de Biofísica Carlos Chagas Filho, Laboratório de Ultraestrutura Celular Hertha Meyer Instituto Nacional de Ciência e Tecnologia (INBEB) and Centro Nacional de Biologia Estrutural e Bioimagens (CENABIO), Rio de Janeiro, 21941-902, Brazil

* Address correspondence to: Marlene Benchimol,

BIOCELL 2021, 45(2), 259-266. https://doi.org/10.32604/biocell.2021.014599

Received 11 October 2020; Accepted 23 December 2020; Issue published 19 February 2021

Abstract

Helium ion scanning microscopy (HIM) is a novel high-resolution scanning microscopy technique that uses helium ions instead of electrons to form images of the highest quality and resolution, providing a sub-nanometer resolution sputter uncoated biological cell. Here, we took advantage of HIM to explore the cell surface of Tritrichomonas foetus, a protist parasite of cattle that provokes hard infection and abortion in cows. We describe thin protrusions, like nanotubes described in other cells, with different sizes (27 nm to 81 nm in thickness) and various lengths (from 73 nm to 2 µm), as well bulbous structures either budding from the cell surface or present in the extremities of some protrusions. The flagella also presented these thin protrusions and different protein decoration, similar to those previously described using freeze-fracture techniques. Nanotubes between two cells were also seen, and their role in infection is discussed. The cell surface was also examined and showed several pits indicative of endocytic activity and other types of arrays of particles. These observations were confirmed using Scanning Electron Microscopy (SEM), negative staining, and conventional thin sectioning for observation by transmission electron microscopy. Our findings provide new and relevant information that may contribute to a better understanding of protozoan biology and its interaction with mammalian cells.

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