Using specific synthetic peptide (p176) derived AgB 8/1-kDa accompanied by modified patient's sera: a novel hypothesis to follow-up of Cystic echinococcosis after surgery

In vitro protoscolicidal effects of lithocholic acid on protoscoleces of Echinococcus granulosus and its mechanism

Surgery has been found to be the best choice of treatment for hydatidosis. However, leakage of cyst contents during surgery is the foremost reason for recurrence of hydatidosis. In this study, we investigated the in vitro efficacy of lithocholic acid (LCA) against Echinococcus granulosus protoscoleces. The protoscoleces were divided into a control group, an albendazole (ABZ) positive control group and LCA intervention groups at concentrations of 0.5, 1, 2, and 3 mmol/L and stained with 0.1% eosin for observation using an inverted microscope; the protoscolecal ultrastructure was examined with SEM and TEM; the activities of ROS, SOD, and caspase-3 were investigated using an ROS kit, SOD kit, and caspase-3 kit, respectively; the contents of HO-1 and NQO-1 were analyzed by enzyme-linked immunosorbent assay; and the expression level of cytochrome c (Ctyc) was analyzed by western blotting. Results: As the concentration of LCA increased, the survival rate of protoscoleces gradually decreased. The microstructure shows that the external shape and internal structure were gradually deformed and collapse. SOD, GSH, HO-1 and NQO-1 decreased more significantly in the 3 mmol/L LCA group. However, ROS levels gradually increased. LCA treatment for 3 days at all concentrations significantly increased caspase-3 activity and expression in a dose-dependent manner. LCA decreased the level of Ctyc protein in vitro. LCA demonstrated a parasiticidal effect on the protoscoleces of Echinococcus granulosus in vitro. LCA may induce apoptosis of E. granulosus protoscoleces by oxidative stress and mitochondrial pathways.

Anaphylactic shock due to ruptured pulmonary hydatid cyst in a young patient from Iran

Introduction

and importance: Hydatidosis is a zoonotic condition caused by contact with the tapeworm Echinococcus granulosus metacestode. The liver and lungs are the most prominent locations for cysts. This is a rare case of pulmonary hydatid cyst (PHC) rupture in a young woman following a severe cough.

Case presentation

On July 9, 2018, a 20-year-old woman presented to our hospital in northern Iran with a complaint of cough with excessive sputum, dyspnea, drooling, symptoms of nausea and vomiting, itching and urticarial. Imaging findings showed evidence of a large, space-occupying mass in the right lung. She underwent a thoracoscopic wedge resection (TWR) as a minimally invasive technique, to remove the wall and contents of the cyst. Also, anaphylactic shock occurred in the patient. Due to hemodynamic disorders and heart and respiratory failure, unfortunately, the patient expired.

Clinical discussion

The rupture of a hydatid cyst may result in irreversible damage. PHC rupture is a serious complication that causes excessive coughing and chest pain. A rupture into the pleural or pericardial cavity is a serious and potentially fatal disease.

Conclusion

Anaphylactic shock should be considered as one of the serious complications of PHC, particularly in young ones. Therefore, early diagnosis and appropriate treatment are essential to prevent severe complications such as anaphylactic shock.

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Anaphylactic shock due to ruptured pulmonary hydatid cyst in a young patient from Iran.

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Radiography and CT scan showed evidence of a large, space-occupying mass in the right lung.

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Early diagnosis and appropriate treatment are essential to prevent severe complications such as anaphylactic shock.

Scolicidal and Apoptotic Activities of 5-hydroxy-1, 4-naphthoquinone as a Potent Agent against Echinococcus granulosus Protoscoleces

Cystic hydatid disease (CHD) is a zoonotic disease with different clinical stages caused by the larval stage of the cestode Echinococcus granulosus. It is important to highlight as a public health problem in various regions of the world. In the current study, the efficacy and apoptotic activity of the liposomal system containing juglone (5-hydroxy-1,4-naphthoquinone) were assessed against protoscoleces (PSCs) in vitro. To this aim, firstly, liposomal vesicles were prepared by the thin-film method. Their physico-chemical features were assessed using Zeta-Sizer and Scanning Electron Microscope (SEM). Subsequently, various concentrations (50, 100, 200, 400, and 800 μg/mL) of juglone nanoliposomes at different exposure times (15, 30, 60, and 120 min) were used against PSCs. Results showed that juglone nanoliposomes at all tested concentrations induced scolicidal effect, however, 800 μg/mL and 400 μg/mL of juglone nanoliposomes could reach 100% mortality in 60 and 120 min, respectively. Additionally, we found that caspase-3 mRNA expression was higher in PSCs treated with juglone nanoliposomes compared to control groups (p < 0.001). Therefore, juglone nanoliposomes are suggested to have a more potent apoptotic effect on PSCs. Generally, optimized doses of juglone nanoliposomes could display significant scolicidal effects. Moreover, further in vivo studies are required to evaluate the efficacy of this nanoliposome.

Screening, construction, and serological identification of the diagnostic antigen molecule EG-06283 for the diagnosis of Echinococcus granulosus

Several strategies exist to prevent and control echinococcosis, a global parasitic disease. However, most treatments are ineffective and adverse effects are common. Therefore, we aimed to screen protoscolex antigen molecules of Echinococcus granulosus to identify a diagnostic biomarker for hydatid disease. Published E. granulosus transcriptome sequencing data were analyzed to screen for antigen molecules that are highly expressed in protoscoleces but not in oncospheres. The membrane protein EG-06283 (annotated as Frizzled-4) was selected from 16 antigens, and its gene fragment was subjected to codon optimization and synthesis. rEG-06283 expression was induced in the pET-24a/EG-06283/BL21 strain; subsequently, the protein was purified and subcutaneously injected into ICR mice at weeks 0, 2, 4, and 6. Blood sampling occurred periodically to quantify serum immunoglobulin G (IgG) levels via enzyme-linked immunosorbent assays (ELISA). Immunogenicity was determined by western blot assays using sera from normal mice and mice with secondary hydatid infections. The antigen's immune reactivity and diagnostic value were validated using sera of patients with hydatid disease. ELISA results confirmed that the antigen molecule induced specific IgG production in mice, resulting in significantly higher levels than those in the adjuvant and control groups (P < 0.05). The western blot results indicated that the protein was recognized by antibodies in the sera of mice with hydatid infection and the antisera of immunized mice. Quantification of protein levels in the sera of patients with hydatid disease significantly differed from levels in healthy participants (P < 0.05). These results indicate that rEG-06283 is a potential diagnostic antigen for E. granulosus infections.

Parasite-derived microRNAs in plasma as novel promising biomarkers for the early detection of hydatid cyst infection and post-surgery follow-up

Currently, cystic echinococcosis (CE) follow-up is a serious concern among surgeons. MicroRNAs (miRNAs) are small, endogenous, non-coding RNAs which are present in human body fluids in a highly stable form. Recently, it is observed that Echinococcus granulosus expresses a large number of miRNAs in its developmental stages. The current study aimed at evaluating the capacity of parasitic miRNAs to serve as plasma biomarkers for hydatid cysts before and after CE surgery. Hydatidosis patients were identified using radiological and histopathological examinations. Following RNA extraction and cDNA synthesis, the expression levels of parasite-derived miRNAs including egr-miR-71 and egr-let-7 were quantitatively evaluated using real-time polymerase chain reaction (RT-PCR) in 30 hydatid cyst-infected individuals before surgery and an equal number of healthy controls. Then, three- and six-month follow-ups were performed after cystectomy. To analyze parasite-derived miRNAs, the relative fold change between uninfected and infected samples was determined and normalized to hsa-miR-16-5p as the housekeeping internal control. RT-PCR demonstrated that egr-miR-71 and egr-let-7 were specifically amplified in all the plasma samples from the infected individuals with hydatid cyst; yet they were significantly down-regulated at three and six months' post-surgery (P < 0.05). The egr-miR-71 had a higher level of expression in larval stage compared with egr-let-7. The results of the current study indicated that hydatid cyst-derived miRNAs including egr-miR-71 and egr-let-7 can be detected in human plasma. Considering the changes in the expression levels of these miRNAs after three and six months, it seems that these miRNAs, especially egr-miR-71, could serve as novel promising biomarkers for the early diagnosis and monitoring of hydatidosis.

A clinical association between Toll-like receptor 2 Arg753Gln polymorphism with recurrent cystic echinococcosis in postsurgery patients: A case control study

Recurrence of hydatid cysts in cystectomy patients has dramatically remained a serious concern within the surgical community. Predisposing factors for recurrence of hydatid cysts remained to be identified. Toll-like receptor (TLR) plays a pivotal role in bridging between acquired and innate immunity in cystic echinococcosis (CE) infection. 117 CE patients including 66 acute hydatidosis (AH; primary infection) and 51 recurrent hydatidosis (RH; chronic infection), and 117 ethnically matched healthy control (HC) were investigated from endemic regions of Iran in the period of 2015-2018. CE patients were definitely confirmed using histopathological and immunological assays. Genotyping of TLR2 Arg753Gln was carried out by restriction fragment length polymorphism and sequencing. The homozygous mutant-type TLR2 Gln/Gln (A/A) was represented to be associated with the occurrence of RH (P = 0.04) and conferred a 9 fold risk for susceptibility, while the heterozygous mutant-type TLR2 Arg/Gln (G/A) indicated a tendency to be associated with the occurrence of RH (P = 0.07). There was no discrepancy in the frequency of TLR2 Arg753Gln haplotypes between AH patients and HC individuals (P = 0.09). The mutant allele A was observed to be a risk factor for susceptibility to RH patients. Our results point to a clinical association between TLR2 Arg753Gln haplotypes with RH in postoperative patients. It can be inferred that allele G may lead to protection against the CE, while mutant allele A may be a diagnostic hallmark in the screening of RH susceptibility. Nevertheless, further studies with a larger sample size of different ethnic populations are required to authenticate this association.

Multi-Epitope Fusion Protein Eg mefAg-1 as a Serodiagnostic Candidate for Cystic Echinococcosis in Sheep

Cystic echinococcosis (CE) in sheep is a hazardous zoonotic parasitic disease that is caused by Echinococcus granulosus (Eg). At present, serological test is an important diagnostic method for Eg infection in domestic animals. Here, a fusion protein Eg mefAg-1 harboring 8 dominant B-cell epitopes of Eg such as antigen B, tetraspanin 1, tetraspanin 6, reticulon and Eg95 was produced in E. coli and evaluated for CE in sheep by indirect ELISA. Eg mefAg-1 showed in ELISA a high sensitivity (93.41%) and specificity (99.31%), with a coincidence rate of 97.02%. Overall, it is suggested that the Eg mefAg-1 could be a potential antigen candidate for CE serodiagnosis in sheep.

Lateral flow dipstick antigen assay for human cystic echinococcosis

Cystic echinococcosis (CE) is a neglected zoonotic disease with a worldwide distribution and is a major public health problem in some areas. Diagnosis of CE is mainly based on clinical symptoms, imaging and serological testing, however, improvement in serodiagnosis is still needed. This study was aimed at detecting circulating Echinococcus antigen in CE patients using a lateral flow dipstick (LFD) assay. Three types of hydatid antigens i.e. hydatid cyst fluid (HCF), native antigen B (nAgB) and recombinant antigen B (rAgB) were prepared and polyclonal rabbit antiserum was raised against each antigen. Purified IgG fractions were prepared and a portion was conjugated to gold nanoparticles. After a series of optimizations, a final antigen detection LFD assay was developed using a combination of anti-nAgB-IgG and gold-conjugated anti-HCF-IgG. Evaluation of the assay showed that 27 out of 35 (77%) serum samples from CE patients gave positive results. Meanwhile, the test showed a diagnostic specificity of 82% when tested with sera from 38 healthy individuals and 13 patients with other parasitic diseases. In conclusion, the antigen detection LFD assay seemed to be useful for diagnosis of CE and possibly for post-treatment follow-up, and merit further evaluation studies. We foresee that it may improve serodiagnosis of CE when used in tandem with an antibody detection test.

Comparative survey on scolicidal effects of selenium and silver nanoparticles on protoscolices of hydatid cyst

Hydatidosis is a zoonotic diseases which affects human and livestock animals. The surgical treatment of hydatid diseases in man is still the most effective approach, but spillage of protoscolices is the risk of surgery. Therefore, it is essential to develop alternative approaches. Injection of protoscolicidal agents into the cysts preoperatively is an alternative method.The aim of the present study was the determination and comparison of lethal effects of silver nanoparticles (Ag-NPs) and selenium nanoparticles (Se-NPs) on protoscolices of hydatid cyst. Livers and lungs of sheep, which was naturally infected by hydatid cyst were collected from Tabriz slaughterhouse and transferred to the parasitology laboratory. Initially, the surface of cysts was disinfected by 70% Alcohol. Then, 25 ml of each cyst fluid were aspirated by sterile syringe and transferred to Erlenmeyer flask. After 30 minutes, the supernatant was discarded and protoscolices were washed with phosphate-buffered saline and tested by 1% eosin to assess their viability. Next, the samples of protoscolices, which were over 90%, were selected and the effect of 50, 125, 250 and 500 (µg/ml) of Se-NPs and Ag-NPs in the exposure times of 10, 20, 30 and 60 min were evaluated. Data were analysed by SAS software and analyzed by Duncan’s comparison test. The significant differences were considered to be p<0.0001.The difference between the scolicidal effects of Se-NPs was statistically significant for all examined concentrations and exposure times compared to the control group (p<0.0001). On the other hand, the scolicidal effect of Ag-NPs in 10 and 20 min exposer was not significant in comparison to the control group. Overall scolicidal effect of Se-NPs was higher than Ag-NPs and the difference was significant (p<0.0001).The results of the present research indicated that it is possible to use Se-NPs as an effective scolicidal treatment. It is suggested the study of employing this compound in vivo or in combination with other procedures in treating hydatid cyst in further studies.

The potential role of toll-like receptor 4 Asp299Gly polymorphism and its association with recurrent cystic echinococcosis in postoperative patients

The study of pathogenesis mechanisms of larval stages in the Taeniidae has recently focused on host genetic factors, particularly toll-like receptor (TLR) variations. However, the potential role of TLR4 polymorphism in hydatidosis has not yet been sufficiently elucidated in postoperative patients. In this case-control investigation, 80 patients from Iran, including 40 with acute hydatidosis (AH) and 40 with recurrent hydatidosis (RH), and 80 ethnically matched controls were evaluated from February 2015 to February 2017. Hydatidosis patients were confirmed using radiological, immunological, and histopathological examinations. Genotyping of Asp299Gly and Thr399Ile of TLR4 single-nucleotide polymorphisms was determined by restriction fragment length polymorphism, sequencing, and phylogenetic strategies. The heterozygous mutant-type TLR4 Asp299Gly genotype indicated a tendency to be associated with the occurrence of RH (P = 0.060) and conferred a 3-fold risk for susceptibility. There was no difference in genotype frequency of Asp299Gly between patients with AH and healthy controls (P = 0.42; OR, 1.82; 95% CI, 0.11-30.1%). Interestingly, a frequency of the G allele (12%: Gly) was observed to be a risk factor for susceptibility to RH patients (P = 0.050; OR, 7.08; 95% CI, 0.97-51.5%). A relative genetic variability of TLR4 Asp299Gly was found in RH patients (haplotype diversity: 0.700) compared to AH patients and healthy controls (Hd: 0.000). The Asp299Gly genotype was dominantly identified in patients with hepatic hydatid cysts. The TLR4 Thr399Ile codon was not detected except in a patient with a pulmonary hydatid cyst. The current findings enhance our knowledge regarding the TLR4 Asp299Gly polymorphism potentially leading to the development of RH, by skewing the immune system towards a Th2 response. Identification of the Asp299Gly codon may be a diagnostic hallmark in RH patients who have undergone unsuccessful postoperative intervention. However, further studies with a higher case number are needed on ethnic population from various geographic regions, in order to confirm this hypothesis.

The seroprevalence rate and population genetic structure of human cystic echinococcosis in the Middle East: A systematic review and meta-analysis

Cystic echinococcosis (CE) represents an increasing public health concern in many parts of the world, including the Middle East. The present study is the first systematic review and meta-analysis to assess the seroprevalence rate and population genetic structure of human CE in the eastern Mediterranean region. To estimate the population genetic structure, Echinococcus sequences of the cytochrome oxidase subunit 1 (cox1) gene isolated from countries from this geographical area were retrieved from the GenBank database. An electronic search for articles from 1990 until 2015 was performed using databases PubMed, ScienceDirect, and Scopus. A total of 53 articles reporting on CE seroprevalence and genotyping data met our eligibility criteria and were included in a meta-analysis. The overall CE seroprevalence rates in the general population and in individuals at high risk of infection were estimated using the random-effect model at 7.4% (95% CI = 4.8-10.6) and 10.7% (95% CI = 7.6-14.3), respectively. Risk factors including age group (P < 0.001), dog ownership (P = 0.03), residence area (P < 0.001), and educational level (P = 0.04) showed a statistically significant association with CE seroprevalence. A pairwise fixation index (Fst), used as an estimation of gene flow, suggested a moderate level of genetic differentiation between members of the E. granulosus sensu stricto (G1-G3) complex from Iranian and Turkish metapopulations (Fst = 0.171). The finding of common haplotypes may represent an ancestral transfer of alleles among populations probably during the early stages of animal domestication. The high CE seroprevalence rates found highlight the necessity of implementing appropriate public education for preventive and control strategies, particularly in individuals at high risk of infection; furthermore, our genetic findings reveal novel molecular data concerning microevolutionary events of Echinococcus isolates among Middle East countries.

Effects of trigonelline inhibition of the Nrf2 transcription factor in vitro on Echinococcus granulosus

The aim of this study was to investigate the impact of trigonelline (TRG) on Echinococcus granulosus, and to explore the inhibition impact of nuclear factor erythroid-2-related factor 2 (Nrf2) signaling pathway on E. granulosus protoscoleces. Echinococcus granulosus protoscoleces were incubated with various concentrations of TRG, and then Nrf2 protein expression and its localization in protoscoleces were detected by western blot analysis and immunofluorescence assay, respectively. Reactive oxygen species (ROS) level in protoscoleces was measured using ROS detection kit. Caspase-3 activity was measured using a caspase-3 activity assay kit, and NAD(P)H quinone oxidoreductase (NQO)-1 and heme oxygenase (HO)-1 activities in protoscoleces were measured by ELISA. The effect of TRG on protoscoleces viability was investigated using 0.1% eosin staining, and ultrastructural alterations in protoscoleces were examined by scanning electron microscopy (SEM). Immunolocalization experiment clearly showed that Nrf2 protein was predominantly present in cells of protoscoleces. TRG treatment reduced NQO-1 and HO-1 activities in protoscoleces, but could increase ROS level at early time. Protoscoleces could not survive when treated with 250 μM TRG for 12 days. SEM results showed that TRG-treated protoscoleces presented damage in the protoscoleces region, including hook deformation, lesions, and digitiform protuberance. Nrf2 protein expression was significantly decreased and caspase-3 activity was clearly increased in protoscoleces treated with TRG for 24 and 48 h, respectively, when compared with that in controls (P < 0.05). Our results demonstrated that TRG had scolicidal activity against E. granulosus protoscoleces. Nrf2 protein was mainly expressed in the cells and TRG could efficiently inhibit the Nrf2 signaling pathway in E. granulosus.

Ruptured pulmonary hydatid cyst: a case report

Ruptured pulmonary hydatid cyst (PHC) is an important clinical problem in endemic areas to echinococcal infection. Herein we present a rare case of ruptured PHC in an adolescent boy that was misdiagnosed as pulmonary tuberculosis in local health center. When sputum specimen was stained by acid-fast staining for detection of Mycobacterium tuberculosis, hooklets of Echinococcus granulosus were observed. A simple chest X-ray showed a multilobulated mass in the lower part of the left lung. Computed tomography scan verified existence of thick walled caviar lesion with irregular air-fluid level. The diagnosis was confirmed at the time of surgery. Misdiagnoses of PHC may even lead to irreparable damages. Therefore, accurate diagnosis is necessary to prevent severe complications.

Diagnostic Accuracy of Antigen 5-Based ELISAs for Human Cystic Echinococcosis

BACKGROUND

Clinical diagnosis and follow up of cystic echinococcosis (CE) are based on imaging complemented by serology. Several immunodiagnostic tests are commercially available, but the development of new tools is still needed to overcome the lack of standardization of the target antigen, generally consisting of a crude extract of Echinococcus granulosus hydatid cyst fluid. In a previous work, we described a chromatographic method for the preparation of a highly enriched Antigen 5 fraction from hydatid cyst fluid. The high reactivity of patient sera against this preparation prompted us to evaluate further this antigen for the serodiagnosis of CE on a larger cohort of samples.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 327 sera from CE patients with heterogeneous conditions for cyst stage, cyst number, organ localization, drug therapy, and surgical intervention, together with 253 sera from healthy controls, were first analyzed by an ELISA based on the Ag5 preparation in two different experimental setups and, in parallel, by a commercial ELISA routinely used in clinical laboratories for CE serodiagnosis. The Ag5 ELISAs revealed different sensitivity (88.3% vs 95.3%) without significant differences in specificity (94.1% vs 92.5%), for the two setups, respectively. Moreover, possible relationships between the Ag5 ELISA absorbance results and clinical variables were investigated. Chi squared test, bivariate logistic regression and multiple regression analyses highlighted differences in the serology reactivity according to pharmacological treatment, cyst activity, and cyst number.

CONCLUSIONS/SIGNIFICANCE

The two Ag5 ELISAs revealed different performances depending on the setup. The good diagnostic sensitivity and the high reliability of the Ag5 preparation method make this antigen a promising candidate for the serodiagnosis of CE. Further studies will be needed to evaluate the ability of our test to provide useful information on specific CE clinical traits.

The first morphometric and phylogenetic perspective on molecular epidemiology of Echinococcus granulosus sensu lato in stray dogs in a hyperendemic Middle East focus, northwestern Iran

Background

Hydatidosis is considered to be a neglected cyclo-zoonotic disease in Middle East countries particularly northwestern Iran which is caused by metacestode of tapeworm Echinococcus granulosus sensu lato. Human hydatidosis is a high public health priority in the area, however there is little known from a morphometric and phylogenetic perspective on molecular epidemiology of adult Echinococcus spp. in Iranian stray dogs.

Methods

80 dogs (38 males and 42 females) were collected during June 2013 to April 2014 in northwestern Iran. The isolated parasites from each dog were distinguished by morphometric keys including small, large hook length and blade length. Subsequently, isolates were confirmed by sequencing of mitochondrial cytochrome oxidase subunit 1 gene.

Results

16 (8 males and 8 females) (Prevalence 20 %) out of 80 dogs were infected to genus Echinococcus. With regard to demographic factors, the frequency of parasitism in both male, female adults and their age groups showed no difference (P > 0.05). The phylogenetic analyses of cox1 sequences firmly revealed the 13 sheep strains (G1), one buffalo strain (G3), one camel strain (G6) and one mixed infection. The findings of rostellar hook morphology show an intraspecies variation range among G1 isolates. However, hook measurements in Echinococcus derived from G1 (sheep strain) were not a significant difference from those G6 and G3 strains. Six unique haplotypes were identified containing a high range of diversity (Haplotype diversity 0.873 vs. Nucleotide diversity 0.02).

Conclusions

First presence of camel strain (G6) in this region seems to indicate that potential intermediate hosts play a secondary role in the maintenance of camel-dog biology. Current findings have heightened our knowledge about determination of Echinococcus prevalence, strains of taxonomy and genotypic trait of parasite in Iranian stray dogs which will also help in the development of strategies for monitoring and control of infected stray dogs in the area.

Scolicidal activity of biosynthesized silver nanoparticles against Echinococcus granulosus protoscolices

Cystic hydatid disease (CHD), a helminth infection with various clinical complications caused by the larval stage of the dog tapeworm Echinococcus granulosus is considered as a public health problem in different regions of the world. To date, scolicidal agents have been broadly applied for inactivation of the fertile cysts and these scolicidal agents have several side effects on patients. Therefore, the objective of this study was to evaluate the scolicidal efficacies of synthesized silver nanoparticles (AgNPs) derived from the aqueous aerial extract of Penicillium aculeatum against protoscolices of CHD in-vitro. Protoscolices were aseptically aspirated from infected livers of sheep with CHD. Various concentrations (0.025, 0.05, 0.1 and 0.15 mg/mL) of green synthesis of Ag-NPs and different exposure times (10, 30, 60 and 120 min) were used against protoscolices of CHD. Viability of protoscolices was confirmed by 0.1% eosin staining. The findings showed that the Ag-NPs at all concentrations have high scolicidal effects. The concentrations 0.1 and 0.15 mg/mL after 120 min of exposure times showed 83% and 90% mortality rate, respectively. The least scolicidal activity of biosynthesized Ag-NPs was 40% (0.025 mg/mL and 10 min). The current investigation indicated that applying biogenic Ag-NPs may be considered as a potential scolicidal agent for CHD surgery due to being economical, safer and non-toxic compared to the used chemical materials. However, further studies are required to evaluate the efficacy of Ag-NPs in vivo.

Echinococcus metacestode: in search of viability markers

Epidemiological studies have demonstrated that most humans infected with Echinococcus spp. exhibit resistance to disease. When infection leads to disease, the parasite is partially controlled by host immunity: in case of immunocompetence, the normal alveolar echinococcosis (AE) or cystic echinococcosis (CE) situation, the metacestode grows slowly, and first clinical signs appear years after infection; in case of impaired immunity (AIDS; other immunodeficiencies), uncontrolled proliferation of the metacestode leads to rapidly progressing disease. Assessing Echinococcus multilocularis viability in vivo following therapeutic interventions in AE patients may be of tremendous benefit when compared with the invasive procedures used to perform biopsies. Current options are F18-fluorodeoxyglucose-positron emission tomography (FDG-PET), which visualizes periparasitic inflammation due to the metabolic activity of the metacestode, and measurement of antibodies against recEm18, a viability-associated protein, that rapidly regresses upon metacestode inactivation. For Echinococcus granulosus, similar prognosis-associated follow-up parameters are still lacking but a few candidates may be listed. Other possible markers include functional and diffusion-weighted Magnetic Resonance Imaging (MRI), and measurement of products from the parasite (circulating antigens or DNA), and from the host (inflammation markers, cytokines, or chemokines). Even though some of them have been promising in pilot studies, none has been properly validated in an appropriate number of patients until now to be recommended for further use in clinical settings. There is therefore still a need to develop reliable tools for improved viability assessment to provide the sufficient information needed to reliably withdraw anti-parasite benzimidazole chemotherapy, and a basis for the development of new alternative therapeutic tools.