Cooperative Interactions between Trichomonas vaginalis and Associated Bacteria Enhance Paracellular Permeability of the Cervicovaginal Epithelium by Dysregulating Tight Junctions

Cervicovaginal microbial features predict Chlamydia trachomatis spread to the upper genital tract of infected women

INTRODUCTION

Chlamydia trachomatis (CT) infection can lead to pelvic inflammatory disease, infertility and other reproductive sequelae when it ascends to the upper genital tract. Factors including chlamydial burden, co-infection with other sexually-transmitted bacterial pathogens and oral contraceptive use influence risk for upper genital tract spread. Cervicovaginal microbiome composition influences CT susceptibility and we investigated if it contributes to spread by analyzing amplicon sequence variants (ASVs) derived from the V4 region of 16S rRNA genes in vaginal samples collected from women at high risk for CT infection and for whom endometrial infection had been determined.

RESULTS

Participants were classified as CT negative (CT-, n=77), CT positive at the cervix (Endo-, n=77), or CT positive at both cervix and endometrium (Endo+, n=66). Although we were unable to identify many significant differences between CT infected and uninfected women, differences in abundance of ASVs representing Lactobacillus iners and L. crispatus subspecies but not dominant lactobacilli were detected. Twelve informative ASVs predicted endometrial chlamydial infection (AUC=0.74), with CT ASV abundance emerging as a key predictor. We also observed a positive correlation between levels of cervically secreted cytokines previously associated with CT ascension and abundance of the informative ASVs.

CONCLUSION

Our findings suggest that vaginal microbial community members may influence chlamydial spread directly by nutrient limitation and/or disrupting endocervical epithelial integrity and indirectly by modulating pro-inflammatory signaling and/or homeostasis of adaptive immunity. Further investigation of these predictive microbial factors may lead to cervicovaginal microbiome biomarkers useful for identifying women at increased risk for disease.

Lactobacillus gasseri and Gardnerella vaginalis produce extracellular vesicles that contribute to the function of the vaginal microbiome and modulate host-Trichomonas vaginalis interactions

Trichomonas vaginalis is an extracellular protozoan parasite of the human urogenital tract, responsible for a prevalent sexually transmitted infection. Trichomoniasis is accompanied by a dysbiotic microbiome that is characterised by the depletion of host-protective commensals such as Lactobacillus gasseri, and the flourishing of a bacterial consortium that is comparable to the one seen for bacterial vaginosis, including the founder species Gardnerella vaginalis. These two vaginal bacteria are known to have opposite effects on T. vaginalis pathogenicity. Studies on extracellular vesicles (EVs) have been focused on the direction of a microbial producer (commensal or pathogen) to a host recipient, and largely in the context of the gut microbiome. Here, taking advantage of the simplicity of the human cervicovaginal microbiome, we determined the molecular cargo of EVs produced by L. gasseri and G. vaginalis and examined how these vesicles modulate the interaction of T. vaginalis and host cells. We show that these EVs carry a specific cargo of proteins, which functions can be attributed to the opposite roles that these bacteria play in the vaginal biome. Furthermore, these bacterial EVs are delivered to host and protozoan cells, modulating host-pathogen interactions in a way that mimics the opposite effects that these bacteria have on T. vaginalis pathogenicity. This is the first study to describe side-by-side the protein composition of EVs produced by two bacteria belonging to the opposite spectrum of a microbiome and to demonstrate that these vesicles modulate the pathogenicity of a protozoan parasite. Such as in trichomoniasis, infections and dysbiosis co-occur frequently resulting in significant co-morbidities. Therefore, studies like this provide the knowledge for the development of antimicrobial therapies that aim to clear the infection while restoring a healthy microbiome.

Gut microbiota and Tritrichomonas foetus infection: A study of prevalence and risk factors based on pet cats

Tritrichomonas foetus (T. foetus) is a protozoal pathogen that infects cats and constitutes a significant cause of chronic colitis and diarrhea. Perturbations in the gut microbiota (GM) are affected by Trichomonas infection. Furthermore, dysregulation of the host GM enhances Trichomonas pathogenicity. However, it remains unclear whether the occurrence of diarrhea is associated with a dysregulation in GM following T. foetus infection in cats. Hence, the primary objective of this investigation was to explore the correlation between T. foetus infection and dysregulation in GM by analyzing fecal samples obtained from pet cats in Henan Province, central China. We randomly collected 898 fecal samples from pet cats living in 11 prefectural cities within Henan Province, and T. foetus was screened with polymerase chain reaction (PCR) amplification based on the 18 S rRNA gene. Subsequently, six T. foetus-positive and six T. foetus-negative samples underwent analysis through 16 S rRNA gene sequencing to evaluate the gut microbiota's composition. The overall prevalence of T. foetus infection among the collected samples was found to be 6.01% (54/898). Notably, a higher prevalence of infection was observed in young, undewormed, unimmunized, and diarrheic pet cats. T. foetus infection was found to significantly alter the composition of the pet cat fecal microbiota, leading to dysfunctions. Moreover, it resulted in a substantial increase in the abundance of Bacteroidetes, Proteobacteria, and Phascolarctobacterium spp., while decreasing the ratio of Firmicutes to Bacteroidetes (F/B) and the abundance of Actinobacteria, Clostridiaceae_Clostridium spp., Phascolarctobacterium spp., SMB53 spp., and Blautia spp. We constructed ROC curves to assess the diagnostic value of specific bacterial taxa in discriminating T. foetus infection. The analysis revealed that Proteobacteria and Clostridiaceae_Clostridium spp. were the most reliable single predictors for T. foetus infection. This finding suggests that alterations in the GM may be strongly associated with T. foetus infections.

Complement receptor 3 is required for maximum in vitro trogocytic killing of the parasite Trichomonas vaginalis by human neutrophil-like cells

Trichomonas vaginalis (Tv) is a parasite that causes trichomoniasis, a prevalent sexually-transmitted infection. Neutrophils are found at the site of infection, and can rapidly kill the parasite in vitro, using trogocytosis. However, the specific molecular players in neutrophil killing of Tv are unknown. Here, we show that complement proteins play a role in Tv killing by human neutrophil-like cells (NLCs). Using CRISPR/Cas9, we generated NLCs deficient in each of three complement receptors (CRs) known to be expressed on human neutrophils: CR1, CR3, and CR4. Using in vitro trogocytosis assays, we found that CR3, but not CR1 or CR4 is required for maximum trogocytosis of the parasite by NLCs, with NLCs lacking CR3 demonstrating ~40% reduction in trogocytosis, on average. We also observed a reduction in NLC killing of Tv in CR3 knockout, but not CR1 or CR4 knockout NLCs. On average, NLCs lacking CR3 had ~50% reduction in killing activity. We also used a parallel approach of pre-incubating NLCs with blocking antibodies against CR3, which similarly reduced NLC killing of parasites. These data support a model in which Tv is opsonized by the complement protein iC3b, and bound by neutrophil CR3 receptor, to facilitate trogocytic killing of the parasite.

Endothelial MICU1 alleviates diabetic cardiomyopathy by attenuating nitrative stress-mediated cardiac microvascular injury

BACKGROUND

Myocardial microvascular injury is the key event in early diabetic heart disease. The injury of myocardial microvascular endothelial cells (CMECs) is the main cause and trigger of myocardial microvascular disease. Mitochondrial calcium homeostasis plays an important role in maintaining the normal function, survival and death of endothelial cells. Considering that mitochondrial calcium uptake 1 (MICU1) is a key molecule in mitochondrial calcium regulation, this study aimed to investigate the role of MICU1 in CMECs and explore its underlying mechanisms.

METHODS

To examine the role of endothelial MICU1 in diabetic cardiomyopathy (DCM), we used endothelial-specific MICU1ecKO mice to establish a diabetic mouse model and evaluate the cardiac function. In addition, MICU1 overexpression was conducted by injecting adeno-associated virus 9 carrying MICU1 (AAV9-MICU1). Transcriptome sequencing technology was used to explore underlying molecular mechanisms.

RESULTS

Here, we found that MICU1 expression is decreased in CMECs of diabetic mice. Moreover, we demonstrated that endothelial cell MICU1 knockout exacerbated the levels of cardiac hypertrophy and interstitial myocardial fibrosis and led to a further reduction in left ventricular function in diabetic mice. Notably, we found that AAV9-MICU1 specifically upregulated the expression of MICU1 in CMECs of diabetic mice, which inhibited nitrification stress, inflammatory reaction, and apoptosis of the CMECs, ameliorated myocardial hypertrophy and fibrosis, and promoted cardiac function. Further mechanistic analysis suggested that MICU1 deficiency result in excessive mitochondrial calcium uptake and homeostasis imbalance which caused nitrification stress-induced endothelial damage and inflammation that disrupted myocardial microvascular endothelial barrier function and ultimately promoted DCM progression.

CONCLUSIONS

Our findings demonstrate that MICU1 expression was downregulated in the CMECs of diabetic mice. Overexpression of endothelial MICU1 reduced nitrification stress induced apoptosis and inflammation by inhibiting mitochondrial calcium uptake, which improved myocardial microvascular function and inhibited DCM progression. Our findings suggest that endothelial MICU1 is a molecular intervention target for the potential treatment of DCM.

NlpC/P60 peptidoglycan hydrolases of Trichomonas vaginalis have complementary activities that empower the protozoan to control host-protective lactobacilli

Trichomonas vaginalis is a human protozoan parasite that causes trichomoniasis, a prevalent sexually transmitted infection. Trichomoniasis is accompanied by a shift to a dysbiotic vaginal microbiome that is depleted of lactobacilli. Studies on co-cultures have shown that vaginal bacteria in eubiosis (e.g. Lactobacillus gasseri) have antagonistic effects on T. vaginalis pathogenesis, suggesting that the parasite might benefit from shaping the microbiome to dysbiosis (e.g. Gardnerella vaginalis among other anaerobes). We have recently shown that T. vaginalis has acquired NlpC/P60 genes from bacteria, expanding them to a repertoire of nine TvNlpC genes in two distinct clans, and that TvNlpCs of clan A are active against bacterial peptidoglycan. Here, we expand this characterization to TvNlpCs of clan B. In this study, we show that the clan organisation of NlpC/P60 genes is a feature of other species of Trichomonas, and that Histomonas meleagridis has sequences related to one clan. We characterized the 3D structure of TvNlpC_B3 alone and with the inhibitor E64 bound, probing the active site of these enzymes for the first time. Lastly, we demonstrated that TvNlpC_B3 and TvNlpC_B5 have complementary activities with the previously described TvNlpCs of clan A and that exogenous expression of these enzymes empower this mucosal parasite to take over populations of vaginal lactobacilli in mixed cultures. TvNlpC_B3 helps control populations of L. gasseri, but not of G. vaginalis, which action is partially inhibited by E64. This study is one of the first to show how enzymes produced by a mucosal protozoan parasite may contribute to a shift on the status of a microbiome, helping explain the link between trichomoniasis and vaginal dysbiosis. Further understanding of this process might have significant implications for treatments in the future.

Tight Junctions, the Key Factor in Virus-Related Disease

Tight junctions (TJs) are highly specialized membrane structural domains that hold cells together and form a continuous intercellular barrier in epithelial cells. TJs regulate paracellular permeability and participate in various cellular signaling pathways. As physical barriers, TJs can block viral entry into host cells; however, viruses use a variety of strategies to circumvent this barrier to facilitate their infection. This paper summarizes how viruses evade various barriers during infection by regulating the expression of TJs to facilitate their own entry into the organism causing infection, which will help to develop drugs targeting TJs to contain virus-related disease.

Gardnerella vaginalis alters cervicovaginal epithelial cell function through microbe-specific immune responses

BACKGROUND

The cervicovaginal (CV) microbiome is highly associated with vaginal health and disease in both pregnant and nonpregnant individuals. An overabundance of Gardnerella vaginalis (G. vaginalis) in the CV space is commonly associated with adverse reproductive outcomes including bacterial vaginosis (BV), sexually transmitted diseases, and preterm birth, while the presence of Lactobacillus spp. is often associated with reproductive health. While host-microbial interactions are hypothesized to contribute to CV health and disease, the mechanisms by which these interactions regulate CV epithelial function remain largely unknown.

RESULTS

Using an in vitro co-culture model, we assessed the effects of Lactobacillus crispatus (L. crispatus) and G. vaginalis on the CV epithelial barrier, the immune mediators that could be contributing to decreased barrier integrity and the immune signaling pathways regulating the immune response. G. vaginalis, but not L. crispatus, significantly increased epithelial cell death and decreased epithelial barrier integrity in an epithelial cell-specific manner. A G. vaginalis-mediated epithelial immune response including NF-κB activation and proinflammatory cytokine release was initiated partially through TLR2-dependent signaling pathways. Additionally, investigation of the cytokine immune profile in human CV fluid showed distinctive clustering of cytokines by Gardnerella spp. abundance and birth outcome.

CONCLUSIONS

The results of this study show microbe-specific effects on CV epithelial function. Altered epithelial barrier function through cell death and immune-mediated mechanisms by G. vaginalis, but not L. crispatus, indicates that host epithelial cells respond to bacteria-associated signals, resulting in altered epithelial function and ultimately CV disease. Additionally, distinct immune signatures associated with Gardnerella spp. or birth outcome provide further evidence that host-microbial interactions may contribute significantly to the biological mechanisms regulating reproductive outcomes. Video Abstract.

Two Different Species of Mycoplasma Endosymbionts Can Influence Trichomonas vaginalis Pathophysiology

Trichomonas vaginalis can host the endosymbiont Mycoplasma hominis, an opportunistic pathogenic bacterium capable of modulating T. vaginalis pathobiology. Recently, a new noncultivable mycoplasma, "Candidatus Mycoplasma girerdii," has been shown to be closely associated with women affected by trichomoniasis, suggesting a biological association. Although several features of "Ca. M. girerdii" have been investigated through genomic analysis, the nature of the potential T. vaginalis-"Ca. M. girerdii" consortium and its impact on the biology and pathogenesis of both microorganisms have not yet been explored. Here, we investigate the association between "Ca. M. girerdii" and T. vaginalis isolated from patients affected by trichomoniasis, demonstrating their intracellular localization. By using an in vitro model system based on single- and double-Mycoplasma infection of Mycoplasma-free isogenic T. vaginalis, we investigated the ability of the protist to establish a relationship with the bacteria and impact T. vaginalis growth. Our data indicate likely competition between M. hominis and "Ca. M. girerdii" while infecting trichomonad cells. Comparative dual-transcriptomics data showed major shifts in parasite gene expression in response to the presence of Mycoplasma, including genes associated with energy metabolism and pathogenesis. Consistent with the transcriptomics data, both parasite-mediated hemolysis and binding to host epithelial cells were significantly upregulated in the presence of either Mycoplasma species. Taken together, these results support a model in which this microbial association could modulate the virulence of T. vaginalis. IMPORTANCE T. vaginalis and M. hominis form a unique case of endosymbiosis that modulates the parasite's pathobiology. Recently, a new nonculturable mycoplasma species ("Candidatus Mycoplasma girerdii") has been described as closely associated with the protozoon. Here, we report the characterization of this endosymbiotic relationship. Clinical isolates of the parasite demonstrate that mycoplasmas are common among trichomoniasis patients. The relationships are studied by devising an in vitro system of single and/or double infections in isogenic protozoan recipients. Comparative growth experiments and transcriptomics data demonstrate that the composition of different microbial consortia influences the growth of the parasite and significantly modulates its transcriptomic profile, including metabolic enzymes and virulence genes such as adhesins and pore-forming proteins. The data on modulation from RNA sequencing (RNA-Seq) correlated closely with those of the cytopathic effect and adhesion to human target cells. We propose the hypothesis that the presence and the quantitative ratios of endosymbionts may contribute to modulating protozoan virulence. Our data highlight the importance of considering pathogenic entities as microbial ecosystems, reinforcing the importance of the development of integrated diagnostic and therapeutic strategies.

Bacterial-Viral Interactions in Human Orodigestive and Female Genital Tract Cancers: A Summary of Epidemiologic and Laboratory Evidence

Infectious agents, including viruses, bacteria, fungi, and parasites, have been linked to pathogenesis of human cancers, whereas viruses and bacteria account for more than 99% of infection associated cancers. The human microbiome consists of not only bacteria, but also viruses and fungi. The microbiome co-residing in specific anatomic niches may modulate oncologic potentials of infectious agents in carcinogenesis. In this review, we focused on interactions between viruses and bacteria for cancers arising from the orodigestive tract and the female genital tract. We examined the interactions of these two different biological entities in the context of human carcinogenesis in the following three fashions: (1) direct interactions, (2) indirect interactions, and (3) no interaction between the two groups, but both acting on the same host carcinogenic pathways, yielding synergistic or additive effects in human cancers, e.g., head and neck cancer, liver cancer, colon cancer, gastric cancer, and cervical cancer. We discuss the progress in the current literature and summarize the mechanisms of host-viral-bacterial interactions in various human cancers. Our goal was to evaluate existing evidence and identify gaps in the knowledge for future directions in infection and cancer.

In Silico Prediction of Potential Drug Combinations for Type 2 Diabetes Mellitus by an Integrated Network and Transcriptome Analysis

Type 2 diabetes mellitus (T2DM) is a heterogeneous disorder, so achieving the desired therapeutic efficacy through monotherapy is tricky. Drug combinations play a vital role in treating multiple complex diseases by providing increased efficacy and reduced toxicity. Here, we adopted a computational framework to discover potential drugs and drug pairs for T2DM. Firstly, we collected T2DM-associated genes and constructed the disease module for T2DM. Then, by quantifying the proximity between drugs and the disease module, we found out potential drugs. Based on the drug-induced gene expression profiles, we further performed Gene Set Enrichment Analysis (GSEA) on these drugs and identified several potential candidates. In addition, through network-based separation, potential drug combinations for T2DM were predicted. Results from this study could provide insights for anti-T2DM drug discovery and rational drug use of existing agents. As a useful computational framework, our approach could also be applied in drug research for other complex diseases.

Women-specific routes of administration for drugs: A critical overview

The woman's body presents a number of unique anatomical features that can constitute valuable routes for the administration of drugs, either for local or systemic action. These are associated with genitalia (vaginal, endocervical, intrauterine, intrafallopian and intraovarian routes), changes occurring during pregnancy (extra-amniotic, intra-amniotic and intraplacental routes) and the female breast (breast intraductal route). While the vaginal administration of drug products is common, other routes have limited clinical application and are fairly unknown even for scientists involved in drug delivery science. Understanding the possibilities and limitations of women-specific routes is of key importance for the development of new preventative, diagnostic and therapeutic strategies that will ultimately contribute to the advancement of women's health. This article provides an overview on women-specific routes for the administration of drugs, focusing on aspects such as biological features pertaining to drug delivery, relevance in current clinical practice, available drug dosage forms/delivery systems and administration techniques, as well as recent trends in the field.

Polymicrobial Interactions Operative during Pathogen Transmission

Pathogen transmission is a key point not only for infection control and public health interventions but also for understanding the selective pressures in pathogen evolution. The “success” of a pathogen lies not in its ability to cause signs and symptoms of illness but in its ability to be shed from the initial hosts, survive between hosts, and then establish infection in a new host. Recent insights have shown the importance of the interaction between the pathogen and both the commensal microbiome and coinfecting pathogens on shedding, environmental survival, and acquisition of infection. Pathogens have evolved in the context of cooperation and competition with other microbes, and the roles of these cooperations and competitions in transmission can inform novel preventative and therapeutic strategies.

Recent advances in the molecular biology of the protist parasite Trichomonas vaginalis

Trichomonas vaginalis is an anaerobic/microaerophilic protist parasite which causes trichomoniasis, one of the most prevalent sexually transmitted diseases worldwide. T. vaginalis not only is important as a human pathogen but also is of great biological interest because of its peculiar cell biology and metabolism, in earlier times fostering the erroneous notion that this microorganism is at the root of eukaryotic evolution. This review summarizes the major advances in the last five years in the T. vaginalis field with regard to genetics, molecular biology, ecology, and pathogenicity of the parasite.

Dysbiosis of fecal microbiota in cats with naturally occurring and experimentally induced Tritrichomonas foetus infection

The protozoal pathogen Tritrichomonas foetus infects the colon of domestic cats and is a major cause of chronic colitis and diarrhea. Treatment failure is common, but antibiotics may improve clinical signs in a subset of cats, leading researchers to question involvement of the colonic microbiota in disease pathogenesis. Studies performed in women with venereal Trichomonas vaginalis infections have revealed that dysbiosis of host microbiota contributes to pathogenicity with similar findings also found in mice with intestinal Tritrichomonas musculis The aim of this study was to characterize differences in the fecal microbiota of cats with and without naturally occurring T. foetus infection and in a group of kittens prior to and after experimentally induced infection. Archived fecal DNA from cats undergoing testing for T. foetus infection (n = 89) and experimentally infected kittens (n = 4; at pre-, 2 weeks, and 9 weeks post-infection) were analyzed by sequencing of 16S rRNA genes. Amongst the naturally infected population, the genera Megamonas and Helicobacter were significantly increased in prevalence and abundance in cats testing positive for T. foetus infection. In the group of four experimentally infected kittens, fecal samples post-infection had significantly lower abundance of genus Dialister and Megamonas and greater abundance of the class Betaproteobacteria and family Succinivibrionaceae. We hypothesize that T. foetus promotes dysbiosis by competition for fermentable substrates used by these bacteria and that metabolic byproducts may contribute to the pathogenesis of colonic inflammation and diarrhea. Future studies are warranted for the measurement of fecal concentrations of microbial and protozoal metabolites in cats with T. foetus infection for the identification of potential therapeutic targets.

Gardnerella and vaginal health: the truth is out there

The human vagina is a dynamic ecosystem in which homeostasis depends on mutually beneficial interactions between the host and their microorganisms. However, the vaginal ecosystem can be thrown off balance by a wide variety of factors. Bacterial vaginosis (BV) is the most common vaginal infection in women of childbearing age but its etiology is not yet fully understood, with different controversial theories being raised over the years. What is generally accepted is that BV is often characterized by a shift in the composition of the normal vaginal microbiota, from a Lactobacillus species dominated microbiota to a mixture of anaerobic and facultative anaerobic bacteria. During BV, a polymicrobial biofilm develops in the vaginal microenvironment, being mainly composed of Gardnerella species. The interactions between vaginal microorganisms are thought to play a pivotal role in the shift from health to disease and might also increase the risk of sexually transmitted infections acquisition. Here, we review the current knowledge regarding the specific interactions that occur in the vaginal niche and discuss mechanisms by which these interactions might be mediated. Furthermore, we discuss the importance of novel strategies to fight chronic vaginal infections.

Anti-trichomonad activities of different compounds from foods, marine products, and medicinal plants: a review

Human trichomoniasis, caused by the pathogenic parasitic protozoan Trichomonas vaginalis, is the most common non-viral sexually transmitted disease that contributes to reproductive morbidity in affected women and possibly to prostate cancer in men. Tritrichomonas foetus strains cause the disease trichomoniasis in farm animals (cattle, bulls, pigs) and diarrhea in domestic animals (cats and dogs). Because some T. vaginalis strains have become resistant to the widely used drug metronidazole, there is a need to develop alternative treatments, based on safe natural products that have the potential to replace and/or enhance the activity of lower doses of metronidazole. To help meet this need, this overview collates and interprets worldwide reported studies on the efficacy of structurally different classes of food, marine, and medicinal plant extracts and some of their bioactive pure compounds against T. vaginalis and T. foetus in vitro and in infected mice and women. Active food extracts include potato peels and their glycoalkaloids α-chaconine and α-solanine, caffeic and chlorogenic acids, and quercetin; the tomato glycoalkaloid α-tomatine; theaflavin-rich black tea extracts and bioactive theaflavins; plant essential oils and their compounds (+)-α-bisabolol and eugenol; the grape skin compound resveratrol; the kidney bean lectin, marine extracts from algae, seaweeds, and fungi and compounds that are derived from fungi; medicinal extracts and about 30 isolated pure compounds. Also covered are the inactivation of drug-resistant T. vaginalis and T. foetus strains by sensitized light; anti-trichomonad effects in mice and women; beneficial effects of probiotics in women; and mechanisms that govern cell death. The summarized findings will hopefully stimulate additional research, including molecular-mechanism-guided inactivations and human clinical studies, that will help ameliorate adverse effects of pathogenic protozoa.

Neutrophil interactions with the sexually transmitted parasite Trichomonas vaginalis: implications for immunity and pathogenesis

Trichomoniasis is the third most common sexually transmitted infection in humans and is caused by the protozoan parasite, Trichomonas vaginalis (Tv). Pathogenic outcomes are more common in women and generally include mild vaginitis or cervicitis. However, more serious effects associated with trichomoniasis include adverse reproductive outcomes. Like other infectious agents, pathogenesis from Tv infection is predicted to be the result of both parasite and host factors. At the site of infection, neutrophils are the most abundant immune cells present and probably play key roles in both parasite clearance and inflammatory pathology. Here, we discuss the evidence that neutrophils home to the site of Tv infection, kill the parasite, and that in some circumstances, parasites possibly evade neutrophil-directed killing. In vitro, the parasite is killed by neutrophils using a novel antimicrobial mechanism called trogocytosis, which probably involves both innate and adaptive immunity. While mechanisms of evasion are mostly conjecture at present, the persistence of Tv infections in patients argues strongly for their existence. Additionally, many strains of Tv harbour microbial symbionts Mycoplasma hominis or Trichomonasvirus, which are both predicted to impact neutrophil responses against the parasite. Novel research tools, especially animal models, will help to reveal the true outcomes of many factors involved in neutrophil-Tv interactions during trichomoniasis.

Co-infection with trichomonas vaginalis increases the risk of cervical intraepithelial neoplasia grade 2-3 among HPV16 positive female: a large population-based study

Background

Evidence suggested that vaginal microbiome played a functional role in the progression of cervical lesions in female infected by HPV. This study aimed at evaluating the influence of common vaginal infection on the carcinogenicity of high risk HPV (hr-HPV).

Methods

From January 15, 2017 to December 31, 2017, 310,545 female aged at least 30 years old had been recruited for cervical cancer screening from 9 clinical research centers in Central China. All the recruited participants received hr-HPV genotyping for cervical cancer screening and vaginal microenvironment test by a high vaginal swab. Colposcopy-directed biopsy was recommended for female who were infected with HPV 16 and HPV 18, and other positive hr-HPV types through test had undertaken triage using liquid-based cytology, cases with the results ≥ ASCUS among them were referred to colposcopy directly, and cervical tissues were taken for pathology examination to make clear the presence or absence of other cervical lesions.

Results

Among 310,545 female, 6067 (1.95%) were tested with positive HPV 16 and HPV 18, 18,297 (5.89%) were tested with other positive hr-HPV genotypes, cervical intraepithelial neoplasia (CIN) 1, CIN 2, CIN 3 and invasive cervical cancer (ICC) were detected in 861 cases, 377 cases, 423 cases, and 77 cases, respectively. Candida albicans and Gardnerella were not associated with the detection of cervical lesions. Positive trichomonas vaginitis (TV) was correlated with hr-HPV infection (p < 0.0001). Co-infection with TV increased the risk of CIN 1 among female infected with hr-HPV (OR 1.18, 95% CI: 1.42–2.31). Co-infection with TV increased the risk of CIN 2–3 among female infected with HPV 16 (OR 1.71, 95% CI: 1.16–2.53).

Conclusions

Co-infection of TV and HPV 16 is a significant factor for the detection of cervical lesions.

Analysis of characteristics of vulvo-vaginal infections in 14- to 18-year-old girls in late puberty

Objective

This study aimed to determine the characteristics of vulvo-vaginal infections in 14- to 18-year-old girls in late puberty.

Methods

From July 2016 to June 2019, 487 14- to 18-year-old girls with vulvo-vaginal infection in late puberty in West China Second University Hospital were retrospectively studied. The incidence of bacterial vaginosis (BV), the intermediate type of BV, vulvo-vaginal candidiasis (VVC), Trichomonas vaginalis (TV), and differences among the incidence of these infections for patients with different ages were analyzed.

Results

The incidence of BV, the intermediate type of BV, TV, VVC, and unknown pathogenic vaginitis was 25.67%, 19.30%, 2.46%, 29.37%, and 23.20%, respectively. The incidence of BV and VVC was significantly higher than that of TV. The incidence of BV in the 17-year-old group was significantly higher than that in other age groups. The incidence of VVC and non-albicans Candida infection in the 17- and 18-year-old groups was significantly higher than that in the 14-year-old group.

Conclusion

Girls in late puberty are more susceptible to suffer from BV and VVC than TV infections. Therefore, more attention should be paid to the effects of menstrual hygiene, female estrogen levels, the vaginal internal environment, and hygiene in vulvo-vaginal infection at this stage.

Mucosal microbial parasites/symbionts in health and disease: an integrative overview

Microbial parasites adapted to thrive at mammalian mucosal surfaces have evolved multiple times from phylogenetically distant lineages into various extracellular and intracellular life styles. Their symbiotic relationships can range from commensalism to parasitism and more recently some host-parasites interactions are thought to have evolved into mutualistic associations too. It is increasingly appreciated that this diversity of symbiotic outcomes is the product of a complex network of parasites-microbiota-host interactions. Refinement and broader use of DNA based detection techniques are providing increasing evidence of how common some mucosal microbial parasites are and their host range, with some species being able to swap hosts, including from farm and pet animals to humans. A selection of examples will illustrate the zoonotic potential for a number of microbial parasites and how some species can be either disruptive or beneficial nodes in the complex networks of host-microbe interactions disrupting or maintaining mucosal homoeostasis. It will be argued that mucosal microbial parasitic diversity will represent an important resource to help us dissect through comparative studies the role of host-microbe interactions in both human health and disease.

Impact of Symbiosis Between Trichomonas vaginalis and Mycoplasma hominis on Vaginal Dysbiosis: A Mini Review

The protozoon Trichomonas vaginalis is responsible for trichomoniasis, a common sexually transmitted infection associated with an increased risk of HIV infection and adverse pregnancy outcomes. The protozoon has the surprising ability to establish a symbiotic relationship with other microorganisms. In fact, most T.vaginalis isolates intracellularly host the vaginal bacterium Mycoplasma hominis and can harbor up to four dsRNA viruses. Moreover, a novel Mycoplasma species named Ca. Mycoplasma girerdii has been recently described as associated with trichomonad cells. Trichomonas vaginalis colonizes the human vagina and its presence causes profound alterations of the resident microbiota, leading to dysbiosis. In healthy women, vaginal microbiota is characterized by the presence of a complex population of aerobic and anaerobic microorganisms living in a physiologically dynamic system dominated by bacteria of the genera Lactobacillus. The most common microbial vaginal imbalance is bacterial vaginosis, a polymicrobial disease associated with several adverse reproductive outcomes and increased risk of HIV infection. Here, we review the current knowledge regarding the interactions between both T.vaginalis and M.hominis and the vaginal microbiota, and we discuss the possibility of a cooperation between T.vaginalis and its symbionts in the development of vaginal dysbiosis.

Development of a convenient detection method for Trichomonas vaginalis based on loop-mediated isothermal amplification targeting adhesion protein 65

BACKGROUND

Trichomoniasis resulting from Trichomonas vaginalis (T. vaginalis) has been considered as a commonly seen disease with the transmission way of sex. At present, the detection methods of T. vaginalis mainly include wet mount microscopy, culture, PCR, immunofluorescence and ELISA. However, all of these detection methods exist shortcomings.

METHODS

In this study, a loop-mediated isothermal amplification (LAMP) assay that targeted the species-specific sequence of adhesion protein 65 (AP65) gene had been conducted to detect T. vaginalis. The optimum reaction system and conditions were optimized in this rapid detection method.

RESULTS

The results of sensitivity analysis showed that the LAMP assay targeting the AP65 gene was 1000 times more sensitive than the nested PCR targeting the actin gene commonly used for detection of T. vaginalis, and the detecting limitation of the former was 10 trichomonad. Moreover, the amplification of the target gene AP65 by LAMP assay exhibited high specificity and the product was exclusively from T. vaginalis. The detection technique of LAMP did not exhibit cross-reactivity with the common pathogens of Trichinella spiralis, Toxoplasma gondii, Escherichia coli, Candida albicans, Staphylococcus aureus, Haemophilus.

CONCLUSIONS

According to the present study, the LAMP assay with the target of AP65 gene, was suitable for the early diagnosis of T. vaginalis infections. Consequently, the LAMP assay was proposed by the current study as a point-of-care examination and an alternative molecular tool which exhibited the potential value in the treatment, control and prevention of trichomoniasis transmission and relevant complication.

Interplay between Histomonas meleagridis and Bacteria: Mutualistic or Predator-Prey?

Histomonas meleagridis is an extracellular protozoan parasite and the aetiological agent of histomonosis, an important poultry disease whose impact is greatly accentuated by inaccessibility of any treatment. A special feature of the parasite is its intricate interplay with bacteria in vitro and in vivo, the focus of this article.

Vaginal dysbiotic bacteria act as pathobionts of the protozoal pathogen Trichomonas vaginalis

Trichomoniasis, a prevalent sexually transmitted infection caused by the protozoan parasite Trichomonas vaginalis, is often accompanied by a vaginal dysbiotic microbiota of pathogenic potential. Our objective was to investigate whether these dysbiotic bacteria act as pathobionts of T. vaginalis infection by altering pathogenic capabilities of the parasite, particularly in regard to adhesion to vaginal substrates and viability of human ectocervical cells. Assays interrogated the performance of T. vaginalis adhesion to biofilm produced by vaginal dysbiotic bacteria and whether these bacteria were capable of altering the ability of the parasite to bind to mucins and cells. The binding activities of T. vaginalis were quantified by flow cytometry. Host cell viability and apoptosis, as affected by T. vaginalis with or without the bacteria, were also measured experimentally. An in vitro biofilm was shown to provide adhesion for T. vaginalis. The binding of parasites to mucins and cells was modulated by the vaginal dysbiotic bacteria. Parasite cytoadhesion was significantly increased by these bacteria. In addition, these bacteria enhanced the pathogenic effects of the parasite to host cells. Together, this study showed that dysbiotic bacteria accompanying T. vaginalis infection in the vagina function as pathobionts as they are capable of enhancing the pathogenic capabilities of this parasite. This study highlights the importance of understanding the contribution of the vaginal microbiome to trichomoniasis.