Species typing of Cuban Trichomonas vaginalis virus by RT-PCR, and association of TVV-2 with high parasite adhesion levels and high pathogenicity in patients

Fraga, Jorge; Rojas, Lázara; Sariego, Idalia; Fernández-Calienes, Aymé; Núñez, Fidel Ángel

doi:10.1007/s00705-012-1353-4

Cited by 27 publications

(19 citation statements)

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“…Three species (abbreviated TVV1 to TVV3) are formally recognized (9, 10), and strains of a putative fourth have been reported (8). Moreover, coinfections of T. vaginalis isolates with two or more TVV species are common (8, 11–13). …”

Section: Introductionmentioning

confidence: 99%

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Structure of a Protozoan Virus from the Human Genitourinary Parasite Trichomonas vaginalis

Parent

Takagi

Cardone

et al. 2013

mBio

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The flagellated protozoan Trichomonas vaginalis is an obligate human genitourinary parasite and the most frequent cause of sexually transmitted disease worldwide. Most clinical isolates of T. vaginalis are persistently infected with one or more double-stranded RNA (dsRNA) viruses from the genus Trichomonasvirus, family Totiviridae, which appear to influence not only protozoan biology but also human disease. Here we describe the three-dimensional structure of Trichomonas vaginalis virus 1 (TVV1) virions, as determined by electron cryomicroscopy and icosahedral image reconstruction. The structure reveals a T = 1 capsid comprising 120 subunits, 60 in each of two nonequivalent positions, designated A and B, as previously observed for fungal Totiviridae family members. The putative protomer is identified as an asymmetric AB dimer consistent with either decamer or tetramer assembly intermediates. The capsid surface is notable for raised plateaus around the icosahedral 5-fold axes, with canyons connecting the 2- and 3-fold axes. Capsid-spanning channels at the 5-fold axes are unusually wide and may facilitate release of the viral genome, promoting dsRNA-dependent immunoinflammatory responses, as recently shown upon the exposure of human cervicovaginal epithelial cells to either TVV-infected T. vaginalis or purified TVV1 virions. Despite extensive sequence divergence, conservative features of the capsid reveal a helix-rich fold probably derived from an ancestor shared with fungal Totiviridae family members. Also notable are mass spectrometry results assessing the virion proteins as a complement to structure determination, which suggest that translation of the TVV1 RNA-dependent RNA polymerase in fusion with its capsid protein involves −2, and not +1, ribosomal frameshifting, an uncommonly found mechanism to date.

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Section: Introductionmentioning

confidence: 99%

“…A few case studies comparing different aspects of trichomoniasis with the presence of TVV in T . vaginalis clinical isolates have noted correlations with patient signs and symptoms, but the case numbers have remained small (5, 13, 20). …”

Section: Introductionmentioning

confidence: 99%

Structure of a Protozoan Virus from the Human Genitourinary Parasite Trichomonas vaginalis

Parent

Takagi

Cardone

et al. 2013

mBio

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“…Five T. vaginalis isolates were investigated and also found that TVV1 was the most prevalent species Goodman et al (2011a). In contrast, other researchers (Fraga et al, 2012) considered only TVV1…”

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confidence: 97%

High rates of double-stranded RNA viruses and Mycoplasma hominis in Trichomonas vaginalis clinical isolates in South Brazil

Becker

Santos

Frasson

et al. 2015

Infection, Genetics and Evolution

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Trichomonas vaginalis is the etiological agent of trichomoniasis, the most common non-viral sexually transmitted disease (STD) in world, with 276.4 million new cases each year. T. vaginalis can be naturally infected with Mycoplasma hominis and Trichomonasvirus species. This study aimed to evaluate the prevalence of T. vaginalis infected with four distinct T. vaginalis viruses (TVVs) and M. hominis among isolates from patients in Porto Alegre city, South Brazil. An additional goal of this study was to investigate whether there is association between metronidazole resistance and the presence of M. hominis during TVV infection. The RNA expression level of the pyruvate ferredoxin oxidoreductase (PFOR) gene was also evaluated among metronidazole-resistant and metronidazole-sensitive T. vaginalis isolates. A total of 530 urine samples were evaluated, and 5.7% samples were positive for T. vaginalis infection. Among them, 4.51% were isolated from female patients and 1.12% were from male patients. Remarkably, the prevalence rates of M. hominis and TVV-positive T. vaginalis isolates were 56.7% and 90%, respectively. Most of the T. vaginalis isolates were metronidazole-sensitive (86.7%), and only four isolates (13.3%) were resistant. There is no statistically significant association between infection by M. hominis and infection by TVVs. Our results refute the hypothesis that the presence of the M. hominis and TVVs is enough to confer metronidazole resistance to T. vaginalis isolates. Additionally, the role of PFOR RNA expression levels in metronidazole resistance as the main mechanism of resistance to metronidazole could not be established. This study is the first report of the T. vaginalis infection by M. hominis and TVVs in a large collection of isolates from South Brazil.

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“…Infection of the female genital tract is capable of significant modification of the vaginal microbiome, potentially resulting in bacterial vaginosis, worsening the symptoms of the infection . As well as organisms present in the vaginal environment, T. vaginalis infection can be impacted by the presence of the intracellular symbionts M. hominis or TVV, which modulate T. vaginalis gene expression in a process thought to increase virulence Fiori et al, 2013;Fraga et al, 2012).…”

Section: Resultsmentioning

confidence: 99%

Trichomonas vaginalis: Clinical relevance, pathogenicity and diagnosis

Edwards

Burke

Smalley

et al. 2014

Critical Reviews in Microbiology

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Trichomonas vaginalis is the etiological agent of trichomoniasis, the most prevalent non-viral sexually transmitted disease worldwide. Trichomoniasis is a widespread, global health concern, and occurring at an increasing rate. Infections of the female genital tract can cause a range of symptoms, including vaginitis and cervicitis, whilst infections in males are generally asymptomatic. The relatively mild symptoms, and lack of evidence for any serious sequelae, have historically led to this disease being under diagnosed, and under researched. However, growing evidence that T. vaginalis infection is associated with disease states with high morbidity in both men and women has increased the efforts to diagnose and treat patients harbouring this parasite. The pathology of trichomoniasis results from damage to the host epithelia, caused by a variety of processes during infection, and recent work has highlighted the complex interactions between the parasite and host, commensal microbiome, and accompanying symbionts. The commercial release of a number of nucleic acid amplification tests (NAATs) has added to the available diagnostic options. Immunoassay based Point of Care testing is currently available, and a recent initial evaluation of a NAAT Point of Care system has given promising results, which would enable testing and treatment in a single visit.

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Species typing of Cuban Trichomonas vaginalis virus by RT-PCR, and association of TVV-2 with high parasite adhesion levels and high pathogenicity in patients

Cited by 27 publications

References 27 publications

Structure of a Protozoan Virus from the Human Genitourinary Parasite Trichomonas vaginalis

Structure of a Protozoan Virus from the Human Genitourinary Parasite Trichomonas vaginalis

High rates of double-stranded RNA viruses and Mycoplasma hominis in Trichomonas vaginalis clinical isolates in South Brazil

Trichomonas vaginalis: Clinical relevance, pathogenicity and diagnosis

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