High Seroprevalence of Toxoplasma Gondii Infection in Female Sex Workers: A Case-Control Study

Eur J Microbiol Immunol (Bp). 2015 Nov 4;5(4):285-92. doi: 10.1556/1886.2015.00039. eCollection 2015.

Alvarado-Esquivel C1, Sánchez-Anguiano LF2, Hernández-Tinoco J2, Arreola-Cháidez E3, López J3, Salcido-Meraz KI3, Estrada-Martínez S2, Navarrete-Flores JA2, Pérez-Álamos AR2, Hernández-Ochoa M3, Rábago-Sánchez E4, Liesenfeld O5.

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Abstract

Through an age- and sex-matched case-control study, we sought to determine whether female sex workers have an increased risk of Toxoplasma gondii exposure and to determine the sociodemographic, work, clinical, and behavioral characteristics of these workers associated with T. gondii exposure. Female workers (n = 136) and controls (n = 272) were examined with enzyme-linked immunoassays (EIA) for the presence of anti-Toxoplasma IgG and IgM antibodies. IgM positive sera were additionally tested with enzyme linked-fluorescence immunoassay (ELFA). Anti-T. gondii IgG antibodies were found in 21 (15.44%) of 136 cases and in 10 (3.67%) of 272 controls (OR = 4.05; 95% CI: 1.84-8.89; P = 0.0001). Anti-T. gondii IgG levels higher than 150 IU/ml were found in 13 (9.6%) of 136 cases and in 8 (2.9%) of 272 controls (P = 0.007). Anti-T. gondii IgM antibodies were found in two cases and in six controls by EIA, but all were negative by ELFA. T. gondii seropositivity was associated with being born out of Durango State (OR = 10.47; 95% CI: 2.9-36.8; P < 0.01), injuries during sex work (OR = 6.30; 95% CI: 1.1-33.7; P = 0.03), and soil contact (OR = 4.11; 95% CI: 1.2-14.0; P = 0.02). This is the first report of an association of T. gondii infection and female sex workers. 

KEYWORDS: 

Toxoplasma gondii; case-control study; female sex workers; risk factors; seroprevalence

PMID:

 

26716017

 

[PubMed]

Preventive Anti-CD2 Treatment does not Impair Parasite Control in a Murine Toxoplasmosis Model

Eur J Microbiol Immunol (Bp). 2015 Nov 12;5(4):306-15. doi: 10.1556/1886.2015.00040. eCollection 2015.

Erben U1, Pawlowski NN2, Heimesaat MM3, Loddenkemper C4, Doerfel K5, Spieckermann S6, Siegmund B1, Kühl AA1.

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Abstract

Targeting human CD2 with the monoclonal antibody (mAb) CB.219 reduces intestinal inflammation in a colitis model where T cells carry human CD2. Here, we asked whether this mAb has adverse effects on infection control. Mice expressing human CD2 on T cells (huCD2tg) were orally infected with Toxoplasma (T.) gondii and treated with the human CD2-specific mAb CB.219 in a preventive setting. The intestinal T. gondii loads in CB.219 treated mice did not differ from the control group. Histologically, huCD2tg mice showed moderate ileal inflammation that did not change with CB.219 treatment. In the ileum, CB.219 treatment reduced the protein levels of interferon-γ, transforming growth factor β and interleukin-6, whereas interleukin-18 mRNA was slightly increased. The infiltration of neutrophils, macrophages, and T cells into the ileum was unaffected by CB.219 treatment. However, CB.219 treatment decreased the numbers of forkhead box P3(+) regulatory T cells (Treg) in ileum and liver of huCD2tg mice. This was confirmed in vitro using human peripheral blood mononuclear cells. Taken together, targeting CD2(+) T cells by the human CD2 mAb CB.219 does not prevent beneficial immune reactions necessary for pathogen control. Further experiments will address gut specificity, underlying mechanisms, and general applicability of CB.219 treatment. 

KEYWORDS: 

CD2; experimental ileitis; infection model; inflammatory bowel disease

PMID:

 

26716019

 

[PubMed]

Toxoplasma Gondii Infection of Chicken Embryos Causes Retinal Changes and Modulates HSP90B1 Gene Expression: A Promising Ocular Toxoplasmosis Model

Eur J Microbiol Immunol (Bp). 2015 Nov 12;5(4):316-20. doi: 10.1556/1886.2015.00024. eCollection 2015.

Nasaré AM1, Tedesco RC1, Cristovam PC2, Cenedese MA3, Galisteo AJ Jr4, Andrade HF Jr4, Gomes JÁ2, Guimarães ÉV5, Barbosa HS5, Alonso LG1.

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Abstract

HSP90B1 is a gene that codifies heat shock protein 108 (HSP108) that belongs to a group of proteins induced under stress situation, and it has close relation with the nervous system, especially in the retina. Toxoplasma gondii causes ocular toxoplasmosis that has been associated with a late manifestation of the congenital toxoplasmosis although experimental models show that morphological alterations are already present during embryological development. Here, we used 18 eyes of Gallus domesticus embryos in 7th and 20th embryonic days to establish a model of congenital ocular toxoplasmosis, experimentally infected in its fifth day correlating with HSP90B1 gene expression. Embryos' eyes were histologically evaluated, and gene expression was performed by real-time polymerase chain reaction (PCR). Our data showed parasite present in the choroid, unusual migration of retinal pigment epithelium, and chorioretinal scars, and a tendency to a lower expression of the HSP90B1 gene upon experimental infection. This is a promising model to better understand T. gondii etiopathogeny. 

KEYWORDS: 

embryo development; experimental models; ocular toxoplasmosis; parasitic ocular infections; regulation of gene expression in development; retina

PMID:

 

26716020

 

[PubMed]

Experimental Models of Ocular Infection with Toxoplasma Gondii

Eur J Microbiol Immunol (Bp). 2015 Dec 4;5(4):293-305. doi: 10.1556/1886.2015.00045. eCollection 2015.

Dukaczewska A1, Tedesco R2, Liesenfeld O1.

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Abstract

Ocular toxoplasmosis is a vision-threatening disease and the major cause of posterior uveitis worldwide. In spite of the continuing global burden of ocular toxoplasmosis, many critical aspects of disease including the therapeutic approach to ocular toxoplasmosis are still under debate. To assist in addressing many aspects of the disease, numerous experimental models of ocular toxoplasmosis have been established. In this article, we present an overview on in vitro, ex vivo, and in vivo models of ocular toxoplasmosis available to date. Experimental studies on ocular toxoplasmosis have recently focused on mice. However, the majority of murine models established so far are based on intraperitoneal and intraocular infection with Toxoplasma gondii. We therefore also present results obtained in an in vivo model using peroral infection of C57BL/6 and NMRI mice that reflects the natural route of infection and mimics the disease course in humans. While advances have been made in ex vivo model systems or larger animals to investigate specific aspects of ocular toxoplasmosis, laboratory mice continue to be the experimental model of choice for the investigation of ocular toxoplasmosis. 

KEYWORDS: 

Toxoplasma gondii; experimental models of toxoplasmic retinochoroiditis; ocular toxoplasmosis

PMID:

 

26716018

 

[PubMed]

Dissecting the interface between apicomplexan parasite and host cell: Insights from a divergent AMA-RON2 pair

Proc Natl Acad Sci U S A. 2015 Dec 28. pii: 201515898. [Epub ahead of print]

Parker ML1, Penarete-Vargas DM2, Hamilton PT3, Guérin A2, Dubey JP4, Perlman SJ3, Spano F5, Lebrun M6, Boulanger MJ7.

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Abstract

Plasmodium falciparum and Toxoplasma gondii are widely studied parasites in phylum Apicomplexa and the etiological agents of severe human malaria and toxoplasmosis, respectively. These intracellular pathogens have evolved a sophisticated invasion strategy that relies on delivery of proteins into the host cell, where parasite-derived rhoptry neck protein 2 (RON2) family members localize to the host outer membrane and serve as ligands for apical membrane antigen (AMA) family surface proteins displayed on the parasite. Recently, we showed that T. gondii harbors a novel AMA designated as TgAMA4 that shows extreme sequence divergence from all characterized AMA family members. Here we show that sporozoite-expressed TgAMA4 clusters in a distinct phylogenetic clade with Plasmodium merozoite apical erythrocyte-binding ligand (MAEBL) proteins and forms a high-affinity, functional complex with its coevolved partner, TgRON2L1. High-resolution crystal structures of TgAMA4 in the apo and TgRON2L1-bound forms complemented with alanine scanning mutagenesis data reveal an unexpected architecture and assembly mechanism relative to previously characterized AMA-RON2 complexes. Principally, TgAMA4 lacks both a deep surface groove and a key surface loop that have been established to govern RON2 ligand binding selectivity in other AMAs. Our study reveals a previously underappreciated level of molecular diversity at the parasite-host-cell interface and offers intriguing insight into the adaptation strategies underlying sporozoite invasion. Moreover, our data offer the potential for improved design of neutralizing therapeutics targeting a broad range of AMA-RON2 pairs and apicomplexan invasive stages.

KEYWORDS: 

Apicomplexa; Toxoplasma gondii; X-ray crystallography; invasion; moving junction

PMID:

 

26712012

 

[PubMed - as supplied by publisher]

MHC Class I Chain-Related Gene A Polymorphisms and Linkage Disequilibrium with HLA-B and HLA-C Alleles in Ocular Toxoplasmosis

PLoS One. 2015 Dec 16;10(12):e0144534. doi: 10.1371/journal.pone.0144534. eCollection 2015.

Ayo CM1,2, Camargo AV1,2, Frederico FB3,2, Siqueira RC1, Previato M1,2, Murata FH1,2, Silveira-Carvalho AP1, Barbosa AP3,2, Brandão de Mattos Cde C1,2, de Mattos LC1,2.

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Abstract

This study investigated whether polymorphisms of the MICA (major histocompatibility complex class I chain-related gene A) gene are associated with eye lesions due to Toxoplasma gondii infection in a group of immunocompetent patients from southeastern Brazil. The study enrolled 297 patients with serological diagnosis of toxoplasmosis. Participants were classified into two distinct groups after conducting fundoscopic exams according to the presence (n = 148) or absence (n = 149) of ocular scars/lesions due to toxoplasmosis. The group of patients with scars/lesions was further subdivided into two groups according to the type of the ocular manifestation observed: primary (n = 120) or recurrent (n = 28). Genotyping of the MICA and HLA alleles was performed by the polymerase chain reaction-sequence specific oligonucleotide technique (PCR-SSO; One Lambda®) and the MICA-129 polymorphism (rs1051792) was identified by nested polymerase chain reaction (PCR-RFLP). Significant associations involving MICA polymorphismswere not found. Although the MICA*002~HLA-B*35 haplotype was associated with increased risk of developing ocular toxoplasmosis (P-value = 0.04; OR = 2.20; 95% CI = 1.05-4.60), and the MICA*008~HLA-C*07 haplotype was associated with protection against the development of manifestations of ocular toxoplasmosis (P-value = 0.009; OR: 0.44; 95% CI: 0.22-0.76), these associations were not statistically significant after adjusting for multiple comparisons. MICA polymorphisms do not appear to influence the development of ocular lesions in patients diagnosed with toxoplasmosis in this study population. 

PMID:

 

26672749

 

[PubMed - in process] 

A Brazilian report using serological and molecular diagnosis to monitoring acute ocular toxoplasmosis

BMC Res Notes. 2015 Dec 7;8:746. doi: 10.1186/s13104-015-1650-6.

Previato M1,2, Frederico FB3,4, Murata FH5,6, Siqueira RC7, Barbosa AP8,9, Silveira-Carvalho AP10, Meira Cda S11,12, Pereira-Chioccola VL13,14, Gava R15,16, Martins Neto PP17, de Mattos LC18,19, de Mattos CC20,21.

Author information

Abstract

BACKGROUND: 

Toxoplasmosis was recently included as a neglected disease by the Center for Disease Control. Ocular toxoplasmosis is one clinical presentation of congenital or acquired infection. The laboratory diagnosis is being used worldwide to support the clinical diagnosis and imaging. The aim of this study was to evaluate the use of serology and molecular methods to monitor acute OT in immunocompetent patients during treatment.

METHODS: 

Five immunocompetent patients were clinically diagnosed with acute OT. The clinical evaluation was performed by ophthalmologic examination using the Early Treatment Diabetic Retinopathy Study, best-corrected visual acuity, slit lamp biomicroscopy, fundoscopic examination with indirect binocular ophthalmoscopy color fundus photography, fluorescein angiography and spectral optical coherence tomography (OCT). Serology were performed by ELISA (IgA, IgM, IgG) and confirmed by ELFA (IgG, IgM). Molecular diagnoses were performed in peripheral blood by cPCR using the Toxoplasma gondii B1 gene as the marker. Follow-up exams were performed on day +15 and day +45.

RESULTS: 

Only five non-immunocompromised male patients completed the follow up and their data were used for analysis. The mean age was 41.2 ± 11.3 years (median: 35; range 31-54 years). All of them were positive for IgG antibodies but with different profiles for IgM and IgA, as well as PCR. For all patients the OCT exam showed active lesions with the inner retinal layers being abnormally hyper-reflective with full-thickness disorganization of the retinal reflective layers, which assumed a blurred reflective appearance and the retina was thickened.

CONCLUSIONS: 

The presence of IgA and IgM confirmed the acute infection and thus was in agreement with the clinical evaluation. Our results show the adopted treatment modified the serological profile of IgM antibodies and the PCR results, but not the IgG and IgA antibodies and that imaging is a good tool to follow-up patients.

PMID:

 

26643197

 

[PubMed - in process] 

PMCID:

 

PMC4671220

 

The ROP18 and ROP5 gene allele types are highly predictive of virulence in mice across globally distributed strains of Toxoplasma gondii

Int J Parasitol. 2015 Dec 14. pii: S0020-7519(15)00312-4. doi: 10.1016/j.ijpara.2015.10.005. [Epub ahead of print]

Shwab EK1, Jiang T1, Pena HF2, Gennari SM2, Dubey JP3, Su C4.

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Abstract

The protozoan parasite Toxoplasma gondii is one of the most successful known eukaryotic pathogens on Earth. Virulence of T. gondii strains varies greatly in mice, and mounting evidence suggests that such variations may be relevant to the manifestation of human toxoplasmosis. Polymorphic rhoptry-secreted kinases and pseudokinases (ROP) have been demonstrated to account for murine virulence among the archetypal clonal parasite lineages that dominate the populations of North America and Europe. However, the distribution of virulence gene alleles in natural populations and the broad influence of these allele combinations on T. gondii virulence have not been examined in depth. In the present study, we performed PCR-RFLP genotyping analysis on a diverse array of globally distributed T. gondii strains at four ROP gene loci including ROP18, ROP5, ROP16 and ROP17 that were previously implicated in influencing T. gondii virulence and pathogenesis. We demonstrated through correlation with published virulence data that the combination of ROP18 and ROP5 allele types is highly predictive of T. gondii virulence across a broad range of global T. gondii isolates. These findings indicate that the importance of ROP18 and ROP5 in determining strain virulence is not limited to the North American/European archetypal lineages most commonly used in molecular studies, but also appears to apply to diverse isolates from South/central America and Asia. RFLP analysis of these loci may thus serve as a valuable tool in determining the potential virulence of uncharacterized T. gondii strains in future studies.

Copyright © 2015. Published by Elsevier Ltd.

KEYWORDS: 

Genotyping; ROP16; ROP17; ROP18; ROP5; Toxoplasma gondii; Virulence

PMID:

 

26699401

 

[PubMed - as supplied by publisher]

A Lipolytic Lecithin:Cholesterol Acyltransferase Secreted by Toxoplasma Facilitates Parasite Replication and Egress

J Biol Chem. 2015 Dec 22. pii: jbc.M115.671974. [Epub ahead of print]

Pszenny V1, Ehrenman K2, Romano JD2, Kennard A1, Schultz A3, Roos DS4, Grigg ME1, Carruthers VB3, Coppens I5.

Author information

Abstract

The protozoan parasite Toxoplasma gondii develops within a parasitophorous vacuole (PV) in mammalian cells, from where it scavenges cholesterol. When cholesterol is present in excess in its environment, the parasite expulses this lipid into the PV or esterifies it for storage in lipid bodies. Here, we characterized a unique T. gondii homologue of mammalian lecithin:cholesterol acyltransferase (LCAT), a key enzyme that produces cholesteryl esters via transfer of acyl groups from phospholipids to the 3-OH of free cholesterol, leading to the removal of excess cholesterol from tissues. TgLCAT contains a motif characteristic of serine lipases AHSLG and the catalytic triad consisting of serine, aspartate and histidine [SDH] of LCAT enzymes. TgLCAT is secreted by the parasite, but unlike other LCAT enzymes, is cleaved into two proteolytic fragments that share the residues of the catalytic triad and that need to be reassembled to reconstitute enzymatic activity. TgLCAT uses phosphatidylcholine as substrate to form lysophosphatidylcholine that has the potential to disrupt membranes. The released fatty acid is transferred to cholesterol, although with a lower transesterification activity than mammalian LCAT. TgLCAT is stored in a subpopulation of dense granule secretory organelles, and following secretion, it localizes to the PV and parasite plasma membrane. LCAT-null parasites have impaired growth in vitro, reduced virulence in animals and exhibit delay in egress from host cells. Parasites overexpressing LCAT show increased virulence and faster egress. These observations demonstrate that TgLCAT influences the outcome of an infection, presumably by facilitating replication and egress depending on the parasite developmental stage.

Copyright © 2015, The American Society for Biochemistry and Molecular Biology.

KEYWORDS: 

Phospholipase A; Toxoplasma gondii; cell surface enzyme; host-pathogen interaction; parasitology

PMID:

 

26694607

 

[PubMed - as supplied by publisher]

Sequence variation and bioinformatics analysis of Toxoplasma gondii GRA16 Gene

Trop Biomed. 2015 Sep;32(3):557-62.

Hu LY1, Zhang NZ2, Gao Q2, Chen J2, Wen FL1, Wang SK1, Zhu XQ2.

Author information

Abstract

Toxoplasmosis is caused by the intracellular protozoan Toxoplasma gondii. It is anopportunistic zoonosis in warm-blooded animals and humans, with a worldwide distribution. Toxoplasma gondii dense granule protein 16 (TgGRA16) can modulate some functions in host cells and is considered a significant virulent factor of the parasite. The present study reports sequence variation in TgGRA16 gene among T. gondii strains from different hosts and geographical locations, and the construction of phylogenetic relationships of these T. gondii strains based on sequences of TgGRA16, and analysis of B cell epitopes in TgGRA16. Our results showed that all TgGRA16 gene sequences were 1518 bp and the C+G contents ranged from 52.17% to 52.59%. Sequence variation in the TgGRA16 gene was 0-1.51%. Phylogenetic analysis revealed that TgGRA16 gene sequence could not be used to differentiate the different T. gondii genotypes. Six B cell epitopes were predicted in TgGRA16. These results indicated that TgGRA16 gene is not an ideal marker for studying genetic relationships of T. gondii isolates, but may represent a good vaccine candidate against toxoplasmosis. 

PMID:

 

26695219

 

[PubMed - in process] 

Characterization of Toxoplasma gondii glyoxalase 1 and evaluation of inhibitory effects of curcumin on the enzyme and parasite cultures

Parasit Vectors. 2015 Dec 23;8(1):654. doi: 10.1186/s13071-015-1268-5.

Goo YK1, Yamagishi J2, Ueno A3, Terkawi MA4, Aboge GO5, Kwak D6, Hong Y7, Chung DI8, Igarashi M9, Nishikawa Y10, Xuan X11.

Author information

Abstract

BACKGROUND: 

The glyoxalase pathway, which includes two enzymes, glyoxalase 1 and 2 (Glo1 and Glo2), is a ubiquitous cellular system responsible for the removal of cytotoxic methylglyoxal produced during glycolysis. Protozoan parasites, including Toxoplasma gondii (T. gondii) tachyzoites, produce methylglyoxal because of increased glycolytic fluxes. A Glo1 inhibitor such as curcumin could be considered a drug candidate for anti-protozoan, anti-inflammatory, and anti-cancer therapy.

METHODS: 

The T. gondii Glo1 gene (TgGlo1) was cloned and the recombinant protein was produced. Enzyme kinetics of TgGlo1 and five mutants were evaluated by adding methylglyoxal and glutathione to a reaction mixture. Finally, the inhibitory effects of various concentrations of curcumin on recombinant TgGlo1 were evaluated using in vitro cultures of T. gondii.

RESULTS: 

Active recombinant TgGlo1 was successfully produced and the active sites (E166 and E251) of TgGlo1 were verified by point mutagenesis. Curcumin at the tested doses inhibited the enzymatic activity of recombinant TgGlo1 as well as the parasitic propagation of in vitro-cultured T. gondii. The Ki and IC50 were 12.9 ± 0.5 μM and 38.3 ± 0.9 μM, respectively.

CONCLUSION: 

The inhibitory effect of curcumin on the enzymatic activity of TgGlo1 and parasitic propagation of T. gondii could be explored in the potential development of a potent drug for the treatment of toxoplasmosis. However, considering the fact that curcumin is known to have many effects on other molecules in the micromolar range, further elucidation of curcumin's direct inhibition of the glyoxalase system of T. gondii will be needed.

PMID:

 

26694921

 

[PubMed - in process]

SAR Studies of 5-Aminopyrazole-4-carboxamide Analogues as Potent and Selective Inhibitors of Toxoplasma gondii CDPK1

ACS Med Chem Lett. 2015 Oct 22;6(12):1184-1189. eCollection 2015.

Huang W1, Ojo KK2, Zhang Z1, Rivas K2, Vidadala RS3, Scheele S4, DeRocher AE4, Choi R2, Hulverson MA2, Barrett LK2, Bruzual I5, Siddaramaiah LK1, Kerchner KM1, Kurnick MD6, Freiberg GM6, Kempf D6, Hol WG1, Merritt EA1, Neckermann G7, de Hostos EL7, Isoherranen N8, Maly DJ3, Parsons M9, Doggett JS5, Van Voorhis WC10, Fan E1.

Author information

Abstract

We previously discovered compounds based on a 5-aminopyrazole-4-carboxamide scaffold to be potent and selective inhibitors of CDPK1 from T. gondii. The current work, through structure-activity relationship studies, led to the discovery of compounds (34 and 35) with improved characteristics over the starting inhibitor 1 in terms of solubility, plasma exposure after oral administration in mice, or efficacy on parasite growth inhibition. Compounds 34 and 35 were further demonstrated to be more effective than 1 in a mouse infection model and markedly reduced the amount of T. gondii in the brain, spleen, and peritoneal fluid, and 35 given at 20 mg/kg eliminated T. gondii from the peritoneal fluid.

KEYWORDS: 

Toxoplasma gondii; calcium-dependent protein kinase-1; enzyme inhibitor; structure−activity relationship studies

PMID:

 

26693272

 

[PubMed]