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Background: Cystic echinococcosis (CE) is a serious parasitic zoonosis caused by the larvae of the tapeworm Echinococcus granulosus. The development of an effective vaccine is one of the most promising strategies for controlling CE., Methods: The E. granulosus 3-hydroxyacyl-CoA dehydrogenase (EgHCDH) gene was cloned and expressed in Escherichia coli. The distribution of EgHCDH in protoscoleces (PSCs) and adult worms was analyzed using immunofluorescence. The transcript levels of EgHCDH in PSCs and adult worms were analyzed using quantitative real-time reverse transcription PCR (RT-qPCR). The immune protective effects of the rEgHCDH were evaluated., Results: The 924-bp open reading frame sequence of EgHCDH, which encodes a protein of approximately 34 kDa, was obtained. RT-qPCR analysis revealed that EgHCDH was expressed in both the PSCs and adult worms of E. granulosus. Immunofluorescence analysis showed that EgHCDH was mainly localized in the tegument of PSCs and adult worms. Western blot analysis showed that the recombinant protein was recognized by E. granulosus-infected dog sera. Animal challenge experiments demonstrated that dogs immunized with recombinant (r)EgHCDH had significantly higher serum IgG, interferon gamma and interleukin-4 concentrations than the phosphate-buffered saline (PBS) control group. The rEgHCDH vaccine was able to significantly reduce the number of E. granulosus and inhibit the segmental development of E. granulosus compared to the PBS control group., Conclusions: The results suggest that rEgHCDH can induce partial immune protection against infection with E. granulosus and could be an effective candidate for the development of new vaccines., (© 2021. The Author(s).)

Background: Cystic echinococcosis (CE) affects predominantly young patients in highly endemic areas. Improved serological methods are needed for the follow-up of CE cases, especially given the high rates of post-surgical relapse that require detection as soon as possible., Methods: We designed a study to investigate the value of antigenic proteins extracted from Echinococcus granulosus (E. granulosus) protoscoleces, and of recombinant B2t and 2B2t proteins, for assessing the efficacy of surgical treatment carried out on CE-affected children. This study was performed on 278 plasma samples collected from 59 Tunisian children surgically treated for CE and monitored for 3 years post-surgery. The patients were classified according to post-surgical outcomes into a "non-relapsed" (NRCE) and a "relapsed" (RCE) group. We performed in-house ELISAs to measure anti-B2t and anti-2B2t IgG and immunoblotting for the detection of IgG against SDS-PAGE-resolved E. granulosus protoscoleces-specific antigens. The Wilcoxon test was applied to assess anti-B2t and anti-2B2t IgG levels. We applied the Cochran Q test to compare the distribution of immunoblotting antigenic bands between 1-month and 1-year post-surgery., Results: The probability of being "relapse-free" when a decrease in antibody titers occurred between 1 month and 1 year post-surgery was 81% and 75%, respectively, for anti-B2t and anti-2B2t IgG. We identified five protoscolex protein bands of 20, 26/27, 30, 40 and 46 kDa as highly immunoreactive by immunoblot for both RCE and NRCE patients at 1 month post-surgery, and significantly lower immunoreactivity after 1 year (p < 10 -4 ) for NRCE compared to RCE patients. The proteins at 26/27 and 40 kDa displayed the best performance in predicting the outcome, with an 84% probability of being relapse-free when the reactivity against the 40 kDa antigen, the doublet at 26/27 kDa, or both was absent or disappeared between 1 month and 1 year post-surgery, and a 93% probability of being relapsed when both bands remained reactive or increased in intensity between the two time points., Conclusions: The B2t protein could be useful for the prediction of CE early post-surgical outcomes. The proteins of E. granulosus protoscoleces, especially the doublet P26/27 and P40, could be promising predictive biomarkers for the post-surgical follow-up of CE cases as well.

Background: Alveolar echinococcosis (AE) is caused by parasitic infection by Echinococcus multilocularis. Its diagnosis is usually based on clinical symptoms, ultrasound, and other imaging methods. MicroRNAs (miRNAs) play important roles in disease processes and can exist in a highly stable cell-free form in body fluids. It is important to identify specific, sensitive diagnostic markers for early diagnosis and evaluation of AE. In this study, we examined hsa-miR-125b-5p as a potential plasma biomarker of E. multilocularis infection., Methods: Plasma samples from patients with AE and healthy individuals were screened for the presence of five miRNAs using miRNA chips. We used quantitative polymerase chain reaction to measure miRNA expression levels in plasma and liver tissue samples from patients with AE., Results: hsa-miR-125b-5p was stably upregulated in the plasma and liver tissue samples from patients with AE., Conclusions: The results suggest that hsa-miR-125b-5p may be a promising biomarker for early, non-invasive diagnosis of AE.

Background: Alveolar echinococcosis (AE) is a zoonotic parasitic disease caused by Echinococcus multilocularis larval tapeworm infections in humans that severely impairs the health of affected patients in the northern hemisphere., Methods: The expression levels of 20 cytokines associated with AE infection were measured by enzyme-linked immunosorbent assay, and the correlations between these cytokines were analysed in the R programming language., Results: Serum cytokine levels differed among individuals in both the AE patient and healthy control groups. The results of the correlations among the cytokines showed obvious differences between the two groups. In the AE patients group, Th1 and Th2 cytokines formed a more complicated network than that in the healthy control group., Conclusions: The altered correlations between Th1 and Th2 cytokines may be closely associated with AE infection, which may provide a new explanation for the essential differences between AE patients and healthy individuals.

Background: As part of an ongoing program that aims to use early detection and timely treatment to improve the control of echinococcosis, especially in younger age groups, we undertook a series of active surveys among Qinghai-Tibetan children in the Qinghai Province of Northwestern China in 2011 and 2012. The significant outcomes that resulted from this study emphasize the need to draw attention to echinococcosis, both alveolar echinococcosis (AE) and cystic echinococcosis (CE), so that policy development is promoted and suitable avenues for control are identified in the highly endemic areas on the Tibetan Plateau., Methods: A total of 19 629 primary school students, aged 6-18 years, with a dominant Tibetan background underwent abdominal ultrasound examination, and 86.4% of the compliant students donated 2-5 ml of venous blood for serological tests. All the abnormal ultrasound results were recorded. If identified as echinococcosis, the disease lesion was assessed according to the WHO-Informal Working Group on Echinococcosis (WHO-IWGE) classification for AE and CE. Among the surveyed students, the prevalence by school was compared among geo-locations, sex and age groups. The clinical image presentations were analyzed according to lesion number, size, the location in the liver and the classification stage. Statistical significance was set at P-value < 0.05 for comparisons among groups., Results: A total of 341 students (1.7%) were identified by ultrasound as having either CE (119, 0.6%) or AE (222, 1.1%). The highest prevalence rates of childhood AE cases occurred in the Tehetu (12.1%) and Moba (11.8%) townships in Dari County. There was a high seropositive rate (37.0%) and a heterogeneous distribution of cases, with a prevalence ranged from 0 to 12.1% for AE and 0-2.9% for CE. Moreover, the seropositive rate ranged from 0.7-45.1% across different schools., Conclusions: The high prevalence of echinococcosis in Qinghai-Tibetan primary school students reflects a lack of knowledge about Echinococcus spp. transmission. The combination of systematic education for children and regularly performed anthelmintic treatment for dogs could achieve the goal of sustainable hydatidosis control.

Background: The larval stage of Echinococcus granulosus is the etiological agent of cystic echinococcosis (CE), which causes serious morbidity and mortality in many areas. There is no reliable method to monitor sheep CE. Here, we characterize E. granulosus glutaredoxin 1 (Eg-Grx1) and report an improved immunodiagnostic method for CE., Methods: We cloned and expressed recombinant Eg-Grx1 and generated antibodies. We analyzed the location of the protein in different parasite stages by fluorescence immunohistochemistry, detected the immunogenicity of recombinant Eg-Grx1, and developed an indirect ELISA (iELISA) for CE serodiagnosis., Results: Eg-Grx1 is a classic dithiol Grx with several GSH-binding motifs. Native Eg-Grx1 protein was distributed in the tegument of protoscoleces, the whole germinal layer, and the parenchymatous tissue of adult worms. Recombinant Eg-Grx1 exhibited good immunoreactivity to CE-infected sheep serum. An iELISA using this antigen showed specificity of 64.3 % (9/14) and sensitivity of 1:3200, and the diagnostic accordance rate was 97.9 % (47/48) compared with the results of necropsy., Conclusion: We characterized a novel Grx (Eg-Grx1) from a parasitic helminth and present a comprehensive analysis of the sequence and structure of this protein. The recombinant Eg-Grx1 protein showed good potential serodiagnostic performance, and we established an iELISA method, which may contribute to the surveillance of sheep CE in epidemic areas.

Background: Cystic echinococcosis (CE), caused by infection with Echinococcus granulosus larvae, is a potentially life-threatening disease in humans. Anaphylactic shock caused by CE is very dangerous, and is highly prevalent during surgery. Dexamethasone (DEX) is used clinically before operations to prevent allergic reactions; Regulatory T cells (Treg cells) are believed to be associated with negative immune response, which play an important role in alleviating allergic reactions. However, the association of Treg cells with DEX remains unknown., Methods: In this study, C57BL/6 mice were divided into uninfected group, untreated group and DEX group which were inoculated with protoscoleces from E. granulosus and sensitized using a cyst fluid suspension to induce anaphylactic shock. In addition, the mice in DEX group were treated with 10 mg/kg DEX by intraperitoneal injection 30 min before being sensitized., Results: It was found that 93.75 % of all sensitized mice experienced allergic symptoms. The levels of IgE, IgE/IgG, and IgE/IgG1 were significantly higher in both untreated group and DEX group. The proportion of CD4 + CD25 + FOXP3 + Treg cells relative to CD4+ Treg cells, and the levels of interleukin-10 (IL-10) and tumor growth factor-β (TGF-β1) were significantly higher in DEX group. The level of IL-13 was significantly higher in the sensitized mice than in the other groups. These cells may play a key role in alleviating the immune response in CE-induced anaphylactic shock., Conclusions: The protective effect of DEX may be due to Treg cell upregulating IL-10 and TGF-β1 levels, and inhibiting helper T cell 2 cytokines.

Background: The neglected tropical diseases, echinococcosis, schistosomiasis and toxoplasmosis are all globally widespread zoonotic diseases with potentially harmful consequences. There is very limited data available on the prevalence of these infections, except for schistosmiasis, in underdeveloped countries. This study aimed to determine the seroprevalence of Echinococcus multilocularis, Schistosoma mansoni, and Toxoplasma gondii antibodies in populations from the Monduli and Babati districts in Tanzania., Methods: A total of 345 blood samples were collected from 160 and 185 randomly selected households from Babati and Monduli districts, Tanzania between February and May of 2012 and analyzed them using the enzyme linked immunosorbent assay. The antibodies were determined using the NovaLisa® Toxoplasma gondii IgG, NovaLisa® Schistosoma Mansoni IgG, NovaLisa® Echinococcus IgG and NovaLisa® Toxoplasma gondii IgM kits (Novatec, Germany)., Results: The seropositivity estimated for E. multilocularis, S. mansoni, and T. gondii IgG was 11.3% (95% confidence interval (CI): 7.96-14.6), 51.3% (95% CI: 46.0-56.5), and 57.68% (95% CI: 52.5-62.9), respectively. The seropositivity for T. gondii IgM was 11.3% (95% CI: 7.96-14.6). Living in the Monduli district was found to be the main risk factor for IgG seropositivity for both schistosomiasis (OR =1.94; 95% CI: 1.23-3.08; p =0.005) and toxoplasmosis (OR =2.09; 95% CI: 1.31-3.33; p =0.002)., Conclusions: These results suggest that restricting disease transmission, implementing control measures, and introducing training projects to increase public awareness are imperative, particularly for the Monduli district.

Background: Cystic echinococcosis (CE) is caused by the larva of tapeworm Echinococcus granulosus. Dogs and other canids are the primary definitive hosts for this parasite. CE may develop after accidental ingestion of tapeworm eggs, excreted with the feces of these animals. In the intestine, the larvae released from the eggs are nested in the liver, lungs or other organs of livestock as intermediate hosts and humans as aberrant hosts. The aim of this study was to examine serologically whether some of the patients in Slovenia, suspected of CE by imaging findings in the liver or lungs had been infected with the larva of Echinococcus granulosus., Methods: Between January 1, 2002 and the end of December 2006, 1323 patients suspected of having echinococcosis were screened serologically by indirect haemagglutination assay (IHA). For confirmation and differentiation of Echinococcus spp. infection, the sera of IHA-positive patients were then retested by western blot (WB)., Results: Out of 127 IHA-positive sera, 34 sera were confirmed by WB and considered specific for CE. Of 34 sera of CE-positive patients sera, 32 corresponded to the characteristic imaging findings of a liver cysts and 2 to those of lung cysts. The mean age of CE-positive patients was 58.3 years. No significant differences were found between the CE-positive patients in regard to their sex., Conclusion: In the study, it was found out that CE was mostly spread in the same area of Slovenia as in the past, but its prevalence decreased from 4.8 per 105 inhabitants in the period 1956-1968 to 1.7 per 105 inhabitants in the period 2002-2006. In spite of the decreased prevalence of CE in the last years, it is suggested that clinicians and public health authorities, especially in the eastern parts of Slovenia where the most CE patients come from, should pay greater attention to this disease in the future.