Experimental infection of sheep at mid-pregnancy with archetypal type II and type III Toxoplasma gondii isolates exhibited different phenotypic traits

Vallejo, Raquel; Benavides, Julio; Arteche-Villasol, Noive; Sánchez-Sánchez, Roberto; Calero‐Bernal, Rafael; Ferreras, M.C.; Criado, Miguel; Pérez, Valentín Pérez; Ortega‐Mora, Luis Miguel; Gutiérrez-Expósito, Daniel

doi:10.1016/j.vetpar.2023.109889

Cited by 3 publications

(5 citation statements)

References 44 publications

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“…Furthermore, since all the sheep and pig serum samples used in our study were obtained after oral infections with oocysts, we could not study the influence of the route of infection or parasite stages in the reactivity and prediction abilities of the tested peptides. As for the influence of the dose of infection, all of our sheep samples belonged to animals infected with 10 oocysts ( Sánchez-Sánchez et al., 2019 ; Vallejo et al., 2023 ), except for a few that were infected with 1000 oocysts of the TgShSp1 strain ( Sánchez-Sánchez et al., 2023 ). Because the number of the latter samples was low (8), we could not draw any conclusions; however, there did not seem to be a difference in the peptides reactivity when comparing both infection doses.…”

Section: Discussionmentioning

confidence: 99%

“…Previous studies from our group have established laboratory developed ELISA protocols for testing sheep and pig serum samples against T. gondii infection ( Sánchez-Sánchez et al., 2019 ; Largo-de la Torre et al., 2022 ; López-Ureña et al., 2023 ; Vallejo et al., 2023 ). In the present work, however, we aimed at standardizing sheep and pig ELISAs using the best conditions with a whole tachyzoite soluble antigen, so as to better compare our results to those obtained in the most recent T. gondii serotyping work performed with mouse and human samples ( Arranz-Solís et al., 2021 ) while minimizing the background noise.…”

Section: Methodsmentioning

confidence: 99%

“…Serum samples were diluted 1:100 in blocking solution, 100 μl added into duplicate wells coated with each of the peptides and the soluble antigen, and subsequently incubated at 37°C for 1 hour. In each plate, the same well-characterized positive and negative control serum samples from previous experiments ( Vallejo et al., 2023 ) were included ( Supplementary File 1 , usage A). Each sample was incubated with the T. gondii soluble antigen and all the peptides in parallel within the same plate to obtain results under the same conditions and to better compare the reactivity of the same sample against all the peptides.…”

Section: Methodsmentioning

confidence: 99%

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A combination of GRA3, GRA6 and GRA7 peptides offer a useful tool for serotyping type II and III Toxoplasma gondii infections in sheep and pigs

Arranz-Solís,

Tana,

Tejerina-de-Uribe

et al. 2024

Front. Cell. Infect. Microbiol.

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The clinical consequences of toxoplasmosis are greatly dependent on the Toxoplasma gondii strain causing the infection. To better understand its epidemiology and design appropriate control strategies, it is important to determine the strain present in infected animals. Serotyping methods are based on the detection of antibodies that react against segments of antigenic proteins presenting strain-specific polymorphic variations, offering a cost-effective, sensitive, and non-invasive alternative to genotyping techniques. Herein, we evaluated the applicability of a panel of peptides previously characterized in mice and humans to serotype sheep and pigs. To this end, we used 51 serum samples from experimentally infected ewes (32 type II and 19 type III), 20 sheep samples from naturally infected sheep where the causative strain was genotyped (18 type II and 2 type III), and 40 serum samples from experimentally infected pigs (22 type II and 18 type III). Our ELISA test results showed that a combination of GRA peptide homologous pairs can discriminate infections caused by type II and III strains of T. gondii in sheep and pigs. Namely, the GRA3-I/III-43 vs. GRA3-II-43, GRA6-I/III-213 vs. GRA6-II-214 and GRA6-III-44 vs. GRA6-II-44 ratios showed a statistically significant predominance of the respective strain-type peptide in sheep, while in pigs, in addition to these three peptide pairs, GRA7-II-224 vs. GRA7-III-224 also showed promising results. Notably, the GRA6-44 pair, which was previously deemed inefficient in mice and humans, showed a high prediction capacity, especially in sheep. By contrast, GRA5-38 peptides failed to correctly predict the strain type in most sheep and pig samples, underpinning the notion that individual standardization is needed for each animal species. Finally, we recommend analyzing for each animal at least 2 samples taken at different time points to confirm the obtained results.

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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A combination of GRA3, GRA6 and GRA7 peptides offer a useful tool for serotyping type II and III Toxoplasma gondii infections in sheep and pigs

Arranz-Solís,

Tana,

Tejerina-de-Uribe

et al. 2024

Front. Cell. Infect. Microbiol.

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“…Different host-and parasitedependent factors were considered as they can greatly influence the immune response elicited by parasite antigens: two parasite infective stages (sporulated oocysts and tissue cysts), different inoculation doses, parasite strains, animal breeds and ages. Samples were classified as positive or negative based on the majority criteria (result obtained by most of the tests), seroconversion was recorded at 2-3 wpi and higher antibody levels corresponded to groups inoculated with type III isolates (Largo-de la Torre et al, 2022;Loṕez-Ureña et al, 2023a;Loṕez-Ureña et al, 2023b;Vallejo et al, 2023).…”

Section: Serum Panelsmentioning

confidence: 99%

“…Panel 3 consisted of sera from non-infected (n= 6) and experimentally infected pregnant sheep (n= 14) orally inoculated with 10 T. gondii oocysts from the isolate TgShSp1 (type II, ToxoDB #3, n= 124) bled at -2, 3, 8, 12, and 14 dpi, with 6 of these sheep also sampled at 21 and 27 dpi (Vallejo et al, 2023). This panel of sera was characterized by Loṕez-Ureña et al antigen-based ELISA, but were found negative by a T. gondii lyophilized tachyzoite-based ELISA and a T. gondii tachyzoite based-WB under reducing conditions (Sańchez-Sańchez et al, 2021).…”

Section: Serum Panelsmentioning

confidence: 99%

Limited value of current and new in silico predicted oocyst-specific proteins of Toxoplasma gondii for source-attributing serology

López-Ureña,

Calero-Bernal,

Koudela

et al. 2023

Front. Parasitol.

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Toxoplasma gondii is a zoonotic parasite infecting all warm-blooded animals, including humans. The contribution of environmental contamination by T. gondii oocysts to infections is understudied. The aim of the current work was to explore T. gondii serology as a means of attributing the source of infection using a robust stepwise approach. We identified in silico thirty-two promising oocyst-specific antigens from T. gondii ´omics data, recombinantly expressed and purified them and validated whether serology based on these proteins could discriminate oocyst- from tissue cyst-driven experimental infections. For this, three well-characterized serum panels, sampled from 0 to 6 weeks post-infection, from pigs and sheep experimentally infected with T. gondii oocysts or tissue cysts, were used. Candidate proteins were initially screened by Western blot with sera from pigs or sheep, infected for different times, either with oocysts or tissue cysts, as well as non-infected animals. Only the recombinant proteins TgCCp5A and TgSR1 provoked seroconversion upon infection and appeared to discriminate between oocyst- and tissue cyst-driven infections with pig sera. They were subsequently used to develop an enzyme-linked immunosorbent assay test for pigs. Based on this assay and Western blot analyses, a lack of stage specificity and low antigenicity was observed with all pig sera. The same was true for proteins TgERP, TgSporoSAG, TgOWP1 and TgOWP8, previously described as source-attributing antigens, when analyzed using the whole panels of sera. We conclude that there is currently no antigen that allows the discrimination of T. gondii infections acquired from either oocysts or tissue cysts by serological tests. This work provides robust new knowledge that can inform further research and development toward source-attributing T. gondii serology.

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Rhoptry proteins affect the placental barrier in the context of Toxoplasma gondii infection: Signaling pathways and functions

Wang,

Qu,

Chen

et al. 2024

Ecotoxicology and Environmental Safety

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Experimental infection of sheep at mid-pregnancy with archetypal type II and type III Toxoplasma gondii isolates exhibited different phenotypic traits

Cited by 3 publications

References 44 publications

A combination of GRA3, GRA6 and GRA7 peptides offer a useful tool for serotyping type II and III Toxoplasma gondii infections in sheep and pigs

A combination of GRA3, GRA6 and GRA7 peptides offer a useful tool for serotyping type II and III Toxoplasma gondii infections in sheep and pigs

Limited value of current and new in silico predicted oocyst-specific proteins of Toxoplasma gondii for source-attributing serology

Rhoptry proteins affect the placental barrier in the context of Toxoplasma gondii infection: Signaling pathways and functions

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