Trichomonas vaginalis
and
Tritrichomonas foetus
are parasitic, flagellated protists that inhabit the urogenital
tract of humans and bovines, respectively.
T. vaginalis causes the most prevalent non-viral sexually transmitted
disease worldwide and has been associated with an increased risk for human immunodeficiency virus-1 infection in
humans. Infections by
T. foetus cause significant losses to the beef industry worldwide due to infertility and spontaneous
abortion in cows. Several studies have shown a close association between trichomonads and the epithelium
of the urogenital tract. However, little is known concerning the interaction of trichomonads with cells from deeper
tissues, such as fibroblasts and muscle cells. Published parasite-host cell interaction studies have reported contradictory
results regarding the ability of
T. foetus and
T. vaginalis to interact with and damage cells of different tissues.
In this study, parasite-host cell interactions were examined by culturing primary human fibroblasts obtained
from abdominal biopsies performed during plastic surgeries with trichomonads. In addition, mouse 3T3 fibroblasts,
primary chick embryo myogenic cells and L6 muscle cells were also used as models of target cells. The parasite-host
cell cultures were processed for scanning and transmission electron microscopy and were tested for cell viability
and cell death. JC-1 staining, which measures mitochondrial membrane potential, was used to determine whether
the parasites induced target cell damage. Terminal deoxynucleotidyltransferase-mediated dUTP nick end labelling
staining was used as an indicator of chromatin damage. The colorimetric crystal violet assay was performed to analyse
the cytotoxicity induced by the parasite. The results showed that
T. foetus and
T. vaginalis adhered to and were
cytotoxic to both fibroblasts and muscle cells, indicating that trichomonas infection of the connective and muscle
tissues is likely to occur; such infections could cause serious risks to the infected host.
