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Bovine cysticercosis is a foodborne zoonosis that has a worldwide distribution, and its highest prevalence is found in developing countries with a large volume of cattle production, such as Brazil. The objective was to evaluate the prevalence of cysticercosis during seven years in three slaughterhouses located in the western region of Minas Gerais state, Brazil, and the impacts of the legislation on the identification and destination of infected carcasses. Three slaughterhouses (Sl) were selected for this study with averages of 200 (SlA), 721 (SlB) and 1138 (SlC) bovines slaughtered per day. The monthly number of slaughtered cattle, infected carcasses with cysticercosis and destination were used to calculate the condemnation occurrence index (COI) and the adjusted seasonal index (ASI). To assess the impact of the legislation, the prevalence rate and destination of infected carcasses were subdivided into the PRE (January 2013 to March 2017) and POST (April 2017 to December 2020) period of Decree 9013 of 2017 and the results were compared by chi-square (P < 0.05). SlA recorded the highest cysticercosis rate with 1.54 % and SlC the lowest rate with 0.33 %. In addition, it was observed that in the POST period there was an increase in the identification of infected carcasses in SlA and B (P < 0.05). The POST period also resulted in a change in the relative frequency of infected carcasses destination in the three slaughterhouses (P < 0.05). The ASI identified an increase in infected carcasses in February and a decrease in November for SlB, proving to be an important tool for planning the inspection team trainings. These results show that the disease is still present in the studied region and highlight the benefits of using the One Health concept in the evaluation of a time series prevalence of bovine cysticercosis by: identifying seasonality of the disease, trends during the time period and impacts brought by updates in the national sanitary legislation.

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A cysticercosis model of Taenia crassiceps ORF strain in susceptible BALB/c mice revealed a Th2 response after 4 weeks, allowing for the growth of the parasite, whereas resistant C57BL/6 mice developed a sustained Th1 response, limiting parasitic growth. However, little is known about how cysticerci respond to an immunological environment in resistant mice. Here, we show that the Th1 response, during infection in resistant C57BL/6 mice, lasted up to 8 weeks and kept parasitemia low. Proteomics analysis of parasites during this Th1 environment showed an average of 128 expressed proteins; we chose 15 proteins whose differential expression varied between 70 and 100%. A total of 11 proteins were identified that formed a group whose expression increased at 4 weeks and decreased at 8 weeks, and another group with proteins whose expression was high at 2 weeks and decreased at 8 weeks. These identified proteins participate in tissue repair, immunoregulation and parasite establishment. This suggests that T. crassiceps cysticerci in mice resistant under the Th1 environment express proteins that control damage and help to establish a parasite in the host. These proteins could be targets for drugs or vaccine development.

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The benzimidazole derivative, 6-chloro-5-(2,3-dichlorophenoxy)-2-(trifluoromethyl)-1H-benzimidazole (RCB15), has a similar mode of action and efficacy as albendazole, a commonly used anthelminthic drugs. The aim of this study was to evaluate its influence on the tricarboxylic acid cycle in Taenia crassiceps cysticerci. The parasites were cultured in supplemented RPMI medium containing albendazole sulfoxide (ABZSO) or RCB15, for 24 h. Then, frozen in liquid nitrogen for organic metabolites extraction. Samples were analyzed by high performance liquid chromatography and organic acids of the tricarboxylic acid cycle were detected. It was possible to observe changes in the concentrations of all acids involved in this metabolic pathway, with the exception of α-ketoglutarate, which was not detected in the control group neither in most of the treated groups. It indicates that the parasite presented a partial inhibition of the tricarboxylic acid cycle. The significant increase in the concentration of citrate, oxaloacetate and succinate in the RCB15 treated groups may indicate an activation of the fumarate reductase pathway, leading to metabolic distress. Therefore RCB15 may be considered an alternative for the treatment of tissue parasitic diseases, since it induced changes in the main metabolic pathway of the parasite.

Assuntos

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The murine infection with Taenia crassiceps WFU (T. crassiceps WFU) cysticerci has been widely used as an experimental model to better understand human cysticercosis. Several reports have established that the host hormonal environment determines the susceptibility and severity of many parasite infections. Female mice are more susceptible to infection with T. crassiceps cysticerci suggesting that a rich estrogen environment facilitates their reproduction. Ovarian androgens and estrogens are synthesized by key enzymes as P450-aromatase and 17α-hydroxilase/17, 20 lyase (P450C17). The aim of this study was to determine the effect of chronic intraperitoneal infection of T. crassiceps WFU cysticerci on mice ovarian follicular development, ovulation, the expression of ovarian P450-aromatase and P450C17, and serum 17ß-estradiol, key enzymes of the ovarian steroidogenic pathway. To perform this study ovaries and serum were obtained at two, four and six months from T. crassiceps WFU cysticerci infected mice, and compared to those of healthy animals. The ovaries were fixed and processed for histology or lysed in RIPA buffer for Western blot using specific antibodies for P450C17 and P450-aromatase. 17ß-estradiol serum concentration was measured by ELISA. The results showed that the infection with T. crassiceps WFU cysticerci significantly reduced the number of primordial and primary follicles after two months of infection. Through the course of the study, the corpus luteum number began to decrease, whereas atretic follicles increased. The expression of ovarian P450C17 and P450-aromatase as well as serum E2 concentration were significantly increased in the infected group compared to control. These findings show that chronic infection with Taenia crassiceps WFU may alter the reproductive functions of the female mice host.

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OBJECTIVE: The aim of this study is to analyze the immune-endocrine profile in neurocysticercosis (NC) patients resistant to cysticidal treatment. METHODS: The inflammatory and regulatory responses of 8 resistant NC patients with extraparenchymal parasites and 5 healthy controls were evaluated through flow cytometry. Serum interleukin levels were measured by ELISA and catecholamines levels by high performance liquid chromatography. RESULTS: Higher percentages of Tr1, CD4+CD25+FOXP3+CD127- and CD4+CD45RO+FOXP3HI were found in NC patients compared with healthy controls, but no difference was found in catecholamine levels. Antigen-specific proliferative immune response was observed in NC patients. Neither anti-inflammatory nor pro-inflammatory cytokines showed differences between patients and controls, but IL-6 levels were lower in treatment-resistant NC patients. In addition, TGFß showed a significant negative correlation with dopamine. CONCLUSIONS: Altogether, these results may point to a modulation of the neuroinflammation in these patients that could indirectly favor cysticercal survival in CNS microenvironment.

Assuntos

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Taeniasis-cysticercosis, a zoonosis caused by Taenia solium, is prevalent in underdeveloped countries, where marginalization promotes its continued transmission. Pig cysticercosis, an essential stage for transmission, is preventable by vaccination. An efficient multiepitope vaccine against pig cysticercosis, S3Pvac, was developed. Previous studies showed that antibodies against one of the S3Pvac components, GK-1, are capable of damaging T. solium cysticerci, inhibiting their ability to transform into the adult stage in golden hamster gut. This study is aimed to evaluate one of the mechanisms that could mediate anti-GK-1 antibody-dependent protection. To this end, pig anti-GK-1 antibodies were produced and purified by using protein A. Proteomic analysis showed that the induced antibodies recognized the respective native cysticercal protein KE7 (Bobes et al. Infect Immun 85:e00395-17, 2017) and two additional T. solium proteins (endophilin B1 and Gp50). A new procedure to evaluate cysticercus viability, based on quantifying the cytochrome c released after parasite damage, was developed. Taenia crassiceps cysticerci were cultured in the presence of differing amounts of anti-GK-1 antibody and complement in a saturating concentration, along with the respective controls. Cysticercus viability was assessed by recording parasite motility, trypan blue exclusion, and cytochrome c levels in cysticercal soluble extract. Anti-GK-1 antibody significantly increased cysticercus damage as measured by all three methods. Parasite evaluation by electron microscopy after treatment with anti-GK-1 antibody plus complement demonstrated cysticercus damage as shorter, capsule-severed microtrichia; a decrease in glycocalyx length with respect to untreated cysts; and disaggregated desmosomes. These results demonstrate that anti-GK-1 antibodies damage cysticerci through classic complement activation.

Assuntos

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BACKGROUND: We have previously reported that progesterone (P4) has a direct in vitro effect on the scolex evagination and growth of Taenia solium cysticerci. Here, we explored the hypothesis that the P4 direct effect on T. solium might be mediated by a novel steroid-binding parasite protein. METHODS: By way of using immunofluorescent confocal microscopy, flow cytometry analysis, double-dimension electrophoresis analysis, and sequencing the corresponding protein spot, we detected a novel PGRMC in T. solium. Molecular modeling studies accompanied by computer docking using the sequenced protein, together with phylogenetic analysis and sequence alignment clearly demonstrated that T. solium PGRMC is from parasite origin. RESULTS: Our results show that P4 in vitro increases parasite evagination and scolex size. Using immunofluorescent confocal microscopy, we detected that parasite cells showed expression of a P4-binding like protein exclusively located at the cysticercus subtegumental tissue. Presence of the P4-binding protein in cyst cells was also confirmed by flow cytometry. Double-dimension electrophoresis analysis, followed by sequencing the corresponding protein spot, revealed a protein that was previously reported in the T. solium genome belonging to a membrane-associated progesterone receptor component (PGRMC). Molecular modeling studies accompanied by computer docking using the sequenced protein showed that PGRMC is potentially able to bind steroid hormones such as progesterone, estradiol, testosterone and dihydrodrotestosterone with different affinities. Phylogenetic analysis and sequence alignment clearly demonstrated that T. solium PGRMC is related to a steroid-binding protein of Echinoccocus granulosus, both of them being nested within a cluster including similar proteins present in platyhelminths such as Schistocephalus solidus and Schistosoma haematobium. CONCLUSION: Progesterone may directly act upon T. solium cysticerci probably by binding to PGRMC. This research has implications in the field of host-parasite co-evolution as well as the sex-associated susceptibility to this infection. In a more practical matter, present results may contribute to the molecular design of new drugs with anti-parasite actions.

Assuntos

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Taeniids tapeworms are hermaphroditic helminths that gradually develop testis and ovaries in their reproductive units. The larval stage of the tapeworms named cysticercus is a vesicle that contains the scolex and proliferates asexually in the abdominal cavity of mice. Once in the host, they evaginate, attach to the gut and develop into an adult organism, the tapeworm. We have previously reported reported that T. crassiceps ORF and solium cysticerci transform steroid precursors to androgens and estrogens. Taenia crassiceps WFU cysticerci can also synthesize corticosteroids. The aim of the present work is to investigate the relationship between steroid synthesis ability and the developmental stage of the parasite T. crassiceps WFU. To this purpose, cysticerci were obtained from the abdominal cavity of female mice, manually separated in invaginated (IC) and evaginated parasites (EC) and preincubated for 24 h in DMEM plus antibiotics/antimycotics. Next step consisted in incubation for different periods in the fresh media added with tritiated androstenedione (3H-A4) or progesterone (3H-P4) and incubated for different periods. Taenia crassiceps WFU tapeworms were recovered from the intestine of golden hamsters that had been orally infected with cysticerci. The worms were pre-cultured in DMEM plus FBS and antibiotics, and then incubated without FBS for different time periods, in the presence of 3H-A4 or 3H-P4. At the end of the experiments the media from cysticerci and tapeworms were analyzed by thin layer chromatography. Results showed that testosterone synthesis was significantly higher in the evaginated cysticerci and increased with time in culture. The invaginated and evaginated cysticerci also synthesized small quantities of 17ß-estradiol (E2) and estrone. The evaginated cysticerci synthesized twice more 3H-deoxycorticosterone (3H-DOC) than the invaginated parasites, the production increased significantly with time in culture. Taenia crassiceps WFU tapeworms synthesized significant quantities of 3H-testosterone and small amounts of estrone after only 3 h of culture in the presence of 3H-A4. The tapeworms also transformed 3H-P4 to 3H-DOC and increased its synthesis after 24 h in culture. In summary, our data show the pathways that T. crassiceps WFU cysticerci use to synthesize sexual steroids in both larval developmental stages and reveals the steroidogenic capacity of the tapeworms.

Assuntos

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In many cases parasites display highly complex life cycles that include the penetration and permanence of the larva or adults within host organs, but even in those that only have one host, reciprocal, intricate interactions occur. Evidence indicates that steroid hormones have an influence on the development and course of parasitic infections. The host gender's susceptibility to infection, and the related differences in the immune response are good examples of the host-parasite interplay. However, the capacity of these organisms to synthesize their own steroidogenic hormones still has more questions than answers. It is now well-known that many parasites synthesize ecdysteroids, but limited information is available on sex steroid and corticosteroid synthesis. This review intends to summarize some of the existing information in the field. In most, but not all parasitosis the host's hormonal environment determines the susceptibility, the course, and severity of parasite infections. In most cases the infection disturbs the host environment, and activates immune responses that end up affecting the endocrine system. Furthermore, sex steroids and corticosteroids may also directly modify the parasite reproduction and molting. Available information indicates that parasites synthesize some steroid hormones, such as ecdysteroids and sex steroids, and the presence and activity of related enzymes have been demonstrated. More recently, the synthesis of corticosteroid-like compounds has been shown in Taenia solium cysticerci and tapeworms, and in Taenia crassiceps WFU cysticerci. In-depth knowledge of the parasite's endocrine properties will contribute to understand their reproduction and reciprocal interactions with the host, and may also help designing tools to combat the infection in some clinical situations.

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The 17ß-hydroxysteroid dehydrogenases (17ß-HSD) are key enzymes involved in the formation (reduction) and inactivation (oxidation) of sex steroids. Several types have been found in vertebrates including fish, as well as in invertebrates like Caenorhabditis elegans, Ciona intestinalis and Haliotis diversicolor supertexta. To date limited information is available about this enzyme in parasites. We showed previously that Taenia solium cysticerci are able to synthesize sex steroid hormones in vitro when precursors are provided in the culture medium. Here, we identified a T. solium 17ß-HSD through in silico blast searches in the T. solium genome database. This coding sequence was amplified by RT-PCR and cloned into the pcDNA 3.1(+) expression vector. The full length cDNA contains 957bp, corresponding to an open reading frame coding for 319 aa. The highest identity (84%) at the protein level was found with the Echinococcus multilocularis 17ß-HSD although significant similarities were also found with other invertebrate and vertebrate 17ß-HSD sequences. The T. solium Tsol-17ßHSD belongs to the short-chain dehydrogenase/reductase (SDR) protein superfamily. HEK293T cells transiently transfected with Tsol17ß-HSD induced expression of Tsol17ß-HSD that transformed 3H-androstenedione into testosterone. In contrast, 3H-estrone was not significantly transformed into estradiol. In conclusion, T. solium cysticerci express a 17ß-HSD that catalyzes the androgen reduction. The enzyme belongs to the short chain dehydrogenases/reductase family and shares motifs and activity with the type 3 enzyme of some other species.

Assuntos

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The experimental system of Taenia crassiceps cysticerci infection in BALB/c mice is considered to be the most representative model of cysticercosis. In our work, mice were sacrificed 7 and 30days after infection, and pouch fluid was collected to determine the number of accumulated cells and the concentrations of IFNγ, IL-2, IL-4, IL-6, IL-10 and nitric oxide. The injection of 50 nonbudding cysticerci into normal mouse dorsal air pouches induced a high level of IFNγ and nitric oxide production relative to the parasite load. The air pouch provides a convenient cavity that allows studying the cellular immunological aspects of the T. crassiceps parasite. The nonbudding cysticerci recovered from the air pouches contained cells that can reconstitute complete cysts in the peritoneal cavity of mice. In conclusion, these results demonstrate that the air pouch model is an alternative tool for the evaluation of the immune characteristics of T. crassiceps infection.

Assuntos

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Although it is widely assumed that both antigen and host immunological variability are involved in the variable intensity of natural porcine infections by Taenia solium (T. solium) cysticercis and success of immunodiagnostic tests vaccines, the magnitude of such combined variability has not been studied or measured at all. In this paper we report statistical data on the variability of the antibody response of naturally infected pigs against the antigens extracted from the vesicular fluids of their own infecting cysts (variance within pigs) and against antigen samples extracted from cysts of other cysticercotic pigs (variance among pigs). The variation between pigs was greater than the inter-pigs variations, which suggests that a concomitant immunity process prevents the establishment of cysts coming from a subsequent challenge. In so doing, we found that there is not a single antigenic band that was recognized by all hosts and that antigens varied among the cysts within the same pigs as well as among pigs. Our results may be valuable for the improvement of immunodiagnostic tests and of effective vaccines against naturally acquired porcine T. solium cysticercosis.

Assuntos

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No existen, hasta el momento, imágenes que muestren la disposición de la citoarquitectura de parásitos adultos de Taenia solium, parásitos los cuales se encuentran en el intestino de portadores humanos asintomáticos. Las causas de ello podrían tener como base el que cuando se recuperan los parásitos, ellos han sufrido alteraciones debidas a la respuesta inmune de sus hospederos o bien, por el efecto que han producido en los parásitos los fármacos antihelmínticos que hayan sido usados en el tratamiento de los pacientes. Una de las alternativas que se han encontrado para la obtención de parásitos adultos, es la obtención de tenias a partir del modelo de teniosis experimental en hámsteres dorados e inmunosuprimidos y que gracias a este modelo se han podido efectuar diferentes tipos de estudios de los parásitos de esta fase infectiva. El propósito de este reporte es presentar imágenes de ultraestructura, obtenidas mediante Microscopía Electrónica de Barrido, de un corte transversal obtenido de un proglótido de una tenia recuperada de una infección experimental. Las imágenes se obtuvieron a diferentes aumentos y muestran aspectos relacionados con la superficie tegumentaria, el tegumento sincicial continuo, la capa germinal que incluye el soma de algunas células subtegumentarias y los ductos del sistema protonefridial tanto vacíos como llenos con corpúsculos calcáreos. Las imágenes ultraestructurales obtenidas muestran una forma de observación de la anatomía microscopica de los parásitos en estudio y ello contribuye a ampliar el conocimiento de los mismos en relación a aspectos de su biología celular y su fisiología.

There are no clear morphological evidences of the cytoarchitecture of intestinal adult tapeworms of Taenia solium recovered from infected humans. Parasites could be altered because of the host´s immunological response or by the direct action of drugs used for antihelminthic treatment. Experimental taeniosis in immunosuppressed golden hamsters is a useful way for recovering and studying adult parasites. The purpose of this report is to show images, taken at the ultrastructural level by Scanning Electron Microscopy (SEM), of a cross-sectioned strobilar chain from an adult tapeworm. The parasite was recovered from an experimental infection. Images were taken at several magnifications; they show the brush border tegumental surface, the syncytial tegument, the germinal layer, some cell bodies and the protonephridial system ducts: empty or filled with calcareous corpuscles. Ultrastructural images taken using SEM of T. solium adult parasites, recovered from experimental infections, could be a new way for observing the microscopic anatomy of these parasites and for increasing the knowledge of aspects related to their cellular biology and physiology.

Assuntos