A large-scale study on the seroprevalence of Toxoplasma gondii infection in humans in Iran.

It is estimated that nearly one-third of the world's human population is infected with Toxoplasma gondii (Nicolle et Manceaux, 1908). Human infection is commonly asymptomatic, multifaceted, and can manifest in severe pathological forms in congenital toxoplasmosis and immunocompromised individuals. This study attempted to recognise the seroprevalence of T. gondii infection in Iranian residents referred to medical laboratories for toxoplasmosis tests throughout the country. This retrospective cross-sectional study was conducted from 2015 to 2019 on individuals referred to diagnostic laboratories in 26 provinces, and these laboratories sent their samples to the referral centres. Accordingly, data associated with serodiagnosis of toxoplasmosis, age, sex, anti-T. gondii IgG, and IgM status in Iranian residents were collected from two referral diagnostic laboratories. All individuals were evaluated using the antibody immunocapture-chemiluminescence assay (CLIA) method with the Immulite®2000s XPi system. In this study, the first large-scale assay of T. gondii infection in Iran, an overall seroprevalence of 30.4% was among 35,047 patients examined. The highest IgM seropositivity rate was in the 10-20 years old patients. In addition, this study showed a very different prevalence of T. gondii across the country, highest in the humid areas, such as the Caspian Sea basin in the North, and the North West with seroprevalence of 48.6%.

Inhibition of mouse colon cancer growth following immunotherapy with a fraction of hydatid cyst fluid.

BACKGROUND: Hydatid cyst is the larval stage of the tape worm Echinococcus granulosus which is located in human and livestock viscera. There are some scientific evidences indicating that parasitic infections induce antitumor activity against certain types of cancers. In this study, the effects of a fraction of hydatid cyst fluid on colon cancer tumor in BALB/c mice were investigated. MATERIALS AND METHODS: In this experimental work six groups of mice were challenged with mouse colon cancer cells. 5 days later when the sign of tumor growth in mice was seen, group 1-4 were injected with hydatid cyst fluid, the 78 kDa fraction, live protoscolices and BCG respectively. Group five was injected with alum alone and the sixth group left intact without any injection. The size of the tumor was measured and compared in all groups. Then blood samples of mice were evaluated for serum cytokine levels. RESULT: In mice injected with hydatid cyst antigens especially a fraction of hydatid cyst fluid, tumor size was smaller than the that of control groups and the difference of tumor size in cases and control groups was statistically significant. CONCLUSION: The results of this study showed that injection of mice with a fraction of hydatid cyst fluid significantly inhibits the growth of mouse colon cancer and this inhibition may be related to effect of immune response to these antigens.

Diagnosis of echinococcosis by detecting circulating cell-free DNA and miRNA.

INTRODUCTION: Diagnosis of echinococcosis is difficult and usually performed based on clinical findings, imaging, and serological test. However, all of them have limitations, especially in follow-up approaches. AREAS COVERED: Detection of cell-free DNA (cfDNA) and micro-RNA (miRNA) is currently a hot topic for diagnosis of echinococcosis diseases. For detecting cell-free DNA in echinococcosis patient's samples such as sera, some techniques are based on next-generation sequencing (NGS), DNA-deep sequencing, some are based on PCR-based methods, and a few works related to the detection of miRNA for the diagnosis of human echinococcosis. EXPERT OPINION: In the detection of cell-free DNA in echinococcosis patient' samples, NGS and DNA-deep sequencing have shown high level of sensitivity, but are not suitable for routine clinical examination as they are expensive and inaccessible in the majority of endemic areas. However, PCR-based methods have shown a sensitivity of about 20-25%. To improve the sensitivity of these tests, improving the DNA extraction method, designing appropriate primers for detecting short-length fragments of circulating DNA, using a higher volume of a serum sample, and application of more sensitive PCR methods are recommended. In the field of miRNA detection, further works are recommended.

Anti-cancer immunoprotective effects of immunization with hydatid cyst wall antigens in a non-immunogenic and metastatic triple-negative murine mammary carcinoma model.

Cancer vaccines have gained lots of attention as the future of cancer treatment. However, poor immunogenicity of tumor-associated antigens often fails to induce an efficient immune response against the tumor. Strange anti-tumor immune responses at the parasite-infected patients due to cross-reactivity have been reported in various studies. Therefore, parasite antigens with significant immunogenicity and high epitope homology with cancer antigens may activate a strong immune response against cancer cells. Herein, the sera of immunized rabbits with the hydatid cyst wall (HCW) antigens were incubated with 4 T1 mammary carcinoma cells to investigate cross-reactivity between the HCW antigens antisera and surface antigens of the breast cancer cells. Also, the SDS-PAGE profile of HCW antigens was prepared and incubated with the breast cancer patients' sera and considerable reactivity was observed between their sera and a specific band (~27/28 kDa) according to Western blotting analyzes. Then, the protein bands with cross-reactivity with breast cancer patients' sera were utilized for prophylactic immunizations of Balb/c mice. The immunoprotective effect of immunization with the HCW antigens caused significant inhibition of 4 T1 breast tumor growth, decrease of metastasis, and enlargement of the tumor-bearing mice survival time in comparison with PBS and pure immune adjuvant injected groups. Mass spectrometry analysis showed that the ~ 27/28 kDa band has numbers of proteins/polypeptides with a high degree of homology with cancer cells antigens which can be the reason for this cross-reactivity and anti-tumor immune response. Taking together, immunization with HCW antigens would be a promising approach in cancer immunotherapy after further investigations.

Renal echinococcosis; the parasite, host immune response, diagnosis and management.

Renal echinococcosis is a rare parasite-caused disease of humans and animals; it makes up about 4% of confirmed cases of cystic echinococcosis. It is a zoonotic disease that occurs in the intermediate hosts harboring the larval stage, the hydatid cyst, of Echinococcus spp. The renal involvement is often asymptomatic or with unspecific signs. Its diagnosis is mostly based on imaging technique. Immunodiagnostic tests are not applicable. Furthermore, because the disease is not common, our knowledge about its different aspects is scarce. In this review, the parasite, host immune response, diagnosis, and management of renal echinococcosis are described.

Immunization with Hydatid Cyst Wall Antigens Can Inhibit Breast Cancer through Changes in Serum Levels of Th1/Th2 Cytokines.

BACKGROUND: Hydatid cysts are the larval stage of Echinococcus granulosus, which lead to humoral and cellular immune responses in hosts. Such immune responses play a key role in the inhibition of tumor growth and cancers. To test this hypothesis, it was attempted not only to examine the changes in serum level of some Th1 and Th2 cytokines but also to find relationships between the cytokines and cancer in 4T1 breast cancer-bearing mice immunized with hydatid cyst wall (HCW) antigens. METHODS: Six to eight-week-old Balb/c female mice were immunized with alum, PBS and HCW antigens, including crude extract of HCW (laminated layer) 28 and 27 kDa protein bands (upper and lower bands) and then challenged with 4T1 breast cancer cells. The amounts of IL2, TNF-α, IFN-γ (Th1 cytokines), and IL4 (Th2 cytokine) were estimated using ELISA. Correlations between these cytokines and cancer parameters (tumor growth, metastasis, and survival) were determined by Pearson's correlation coefficients. RESULTS: Overall, HCW antigens increased the amounts of IL2, TNF-α, IFN-γ, and IL4. Pearson's correlation coefficients indicated reverse relationships between changes in amounts of these cytokines and tumor growth/metastasis. However, except for IL-4, all cytokines had a direct relationship with mouse survival. CONCLUSIONS: The results of this study indicated that the inhibition of breast tumor growth and metastasis and improvement of survival in 4T1 mice immunized with HCW antigens, especially laminated layer and 27 kDa protein band can occur through a rise in the levels of cytokines.

Correction to: Isolated Human and Livestock Echinococcus granulosus Genotypes Using Real-Time PCR of cox1 Gene in Northeast Iran.

Unfortunately, the affiliation of Majid Fasihi­Harandi needs to be edited.

Isolated Human and Livestock Echinococcus granulosus Genotypes Using Real-Time PCR of cox1 Gene in Northeast Iran.

PURPOSE: Cystic echinococcosis (CE), caused by the metacestode of Echinococcus granulosus, is highly endemic over large parts of Iran. The purpose of this study was to investigate the prevalence rate of hydatidosis and mitochondrial cox1 real-time PCR with high-resolution melting curve (HRM) analysis of E. granulosus isolated from human and livestock. METHODS: In this cross-sectional study, 61 formalin-fixed paraffin-embedded tissue isolates were collected from human CE cases and 83 hydatid cysts from the liver and lung lesions of the livestock in Khorasan Razavi province, Northeast Iran. DNA was extracted from each isolate and amplified by real-time PCR and analyzed using the HRM method. RESULTS: The HRM analysis using the cox1 gene of 40 E. granulosus human isolates showed that 35 (87.5%), 4 (10%), and 1 (2.5%) of the isolates were categorized as G1, G3, and G6 genotypes, respectively. Out of the total 1342 livestock inspected, 39 (4%) goats and 44(12%) cattle were found harboring hydatid cysts all belonging to E. granulosus sensu stricto. CONCLUSION: The results confirmed that the high prevalence of E. granulosus sensu stricto in intermediate hosts is remarkable in northeast of Iran coupled with the high prevalence of infection in livestock, which reinforced the need for hydatidosis control programs in this region.

Effect of Hydatid Cyst Fluid Antigens on Induction of Apoptosis on Breast Cancer Cells.

BACKGROUND: Hydatid cyst is a zoonotic and parasitic disease with worldwide distribution. Anticancer effects of hydatid cyst have been shown in cell culture experiments and animal model investigations. The mechanism of anti-cancer effects of hydatid cyst fluid has not been clearly elucidated, and the induction of apoptosis may have a role in this regard. Hence, in this study, the effect of hydatid cyst fluid (HCF) on the induction of apoptosis on mouse breast cancer (4T1) cell line in cell culture medium has been investigated. MATERIALS AND METHODS: Echinococcus granulosus HCF antigens including Antigen B (AgB), glycolipid, glycoprotein, and 78 KDa fractions were prepared. Breast cancer cell line (4T1) was cultured in RPMI-1640 medium supplemented with 10% fetal bovine serum and appropriate antibiotics. Apoptosis was determined by flow cytometry using the annexin V-fluorescein isothiocyanate apoptosis kit. RESULTS: The 78 KDa and glycoprotein fractions induced more than 40% apoptosis. HCF and glycolipid antigens induced 39% and 34% apoptosis, respectively. However, less apoptosis observed after treatment with AgB fraction. CONCLUSION: Hydatid cyst antigens especially the 78 KDa and glycoprotein fractions induced apoptosis on mouse breast cancer cells.

Effect of hydatid cyst antigens on inhibition of melanoma cancer growth in mouse model.

Cancer is the main cause of death in the developed countries. There are some scientific evidences indicating that parasitic infections induce antitumor activity against certain types of cancers. Hydatid cyst is the larval stage of Echinococcus granulosus, which causes hydatidosis in human and livestock. We have already shown that vaccination of mice with hydatid cyst crude antigens and subsequently challenge them with cancer cells, causes inhibition of melanoma cancer growth. In this study, therapeutic effects of hydatid cyst antigens on C57/black mice that had already been challenged with melanoma tumor were investigated. In this experimental study, 6 groups of C57 black mice were subcutaneously inoculated with melanoma cancer cells (line B16F10) in PBS inside their chest site. After 2 weeks case groups were injected with hydatid cyst fluid, a fraction of cyst fluid, live protoscolices or BCG.  control groups were injected with alum alone and other control group was left intact without any intervention. The size of each tumor was measured in all mice. Blood samples were also taken to estimate Interleukin-2 (IL-2), Tumor necrosis factor alpha (TNF-α), Interferon gamma (IFN-γ) and Interleukin-4 (IL-4) levels. Treatment of mice bearing melanoma cancer with hydatid cyst antigens resulted in inhibition of tumor growth and the difference between mean size of tumor in case and control groups was statistically significant. Also, according to our results mean level of measured cytokines between case and control groups was statistically different. Hydatid cyst antigens have anti-melanoma activities and this effect may be related to immune response to parasite antigens.

Th1/Th2-type cytokine profile in C57 black mice inoculated with live Echinococcus granulosus protoscolices.

BACKGROUND AND OBJECTIVE: Cystic echinococcosis (CE) is a widespread parasitic disease caused by infection with the larval stage of a tapeworm, Echinococcus granulosus. The immune response to hydatid cyst in intermediate hosts is a complex and contradictory issue. It is suggested that a Th2 response would favor the establishment of the parasite, whereas a Th1 response would be lethal for the parasite. Thus, the aim of the present study was to evaluate the levels of IL2, TNFα, and IFNγ as T helper (Th)1-type cytokines, IL4 as a Th2-type cytokine, and total IgG in C57/black mice inoculated with E. granulosus protoscoleces (PSCs). MATERIALS AND METHOD: In this experimental study, six C57/black mice were intraperitoneally inoculated with live E. granulosus PSCs and a control group consist of six C57/black mice received normal saline. The quantitative concentrations of IL2, TNFα, IFNγ, and IL4 were determined in the first, second, fourth, eighth and 12th-week post inoculation in both case and control groups. RESULTS: The results showed that at the early post-infection phase (3-4 weeks) the Th1-type cytokine profile was predominant, however the shift to Th2-type cytokine took place in the 4th week. CONCLUSION: Based on the results of the present study, we can suggest that the shift from Th1 to Th2 reactivity may be associated with persistent of the disease because Th2 reactivity may be less effective than Th1 reactivity in countering the parasite.

Molecular Studies on Cystic Echinococcosis of Camel (Camelus dromedarius) and Report of Echinococcus ortleppi in Iran.

BACKGROUND: Cystic echinococcosis (CE) is one of the most important zoonotic diseases; caused by different genotypes of Echinococcus spp. Camels have an important role in transmission cycle of E. granulosus especially, in desert areas. This study aimed to investigate molecular characterization of hydatid cysts isolates from one-humped camel (Camelus dromedarius) and to show its molecular and phylogenic status in this important CE host in the central part of Iran. METHODS: Twenty hydatid cyst samples (14 fertile and 6 calcified) were collected from 56 slaughtered camels in Central part of Iran. Extraction of DNA from 14 fertile samples was achieved followed by molecular studies on two mitochondrial genes (nad1 and cox1). RESULTS: Blast and phylogenetic analysis on sequenced genes showed the presence of G1 (28.6%), G3 (28.6%) and G6 (35.7%) genotypes in the samples. However, one sample was detected as E. ortleppi (G5) with 99% homology with G5 isolated from camel in Egypt (AB921055) and Sudan (JX912709). CONCLUSION: Presence of E. ortleppi, originally the cattle genotype, is reported for the first time in Iran. Due to the potential of infecting human by E. ortleppi; more attention should be paid to this zoonotic genotype in this region.

Antibody response to glycan antigens of hydatid cyst fluid, laminated layer and protoscolex of Echinococcus granulosus.

Background: Hydatid disease is characterized by long-term growth of hydatid cysts in the human. The glycan antigens have an important role in the immunology of hydatid cyst. In this study immunological reaction of host sera to different glycan antigens of the cyst, has been investigated. Methods: The antibody responses were tested to glycoprotein and glycolipid of the laminated layer (LL), cyst fluid (CF) and protoscolex (PS) antigens of E. Granulosus using ELISA and western immunoblotting tests. Thin-layer chromatography and ß-elimination were used for glycan purification. Results: Both hydatid cyst and normal human sera reacted with hydatid cyst fluid, protoscolices, laminated layer, glycoprotein and glycolipid antigens. The most antigen-antibody reaction was related to CF and PS antigens, and LL antigens had the minimal reaction with the sera. Thin layer chromatography (TLC) of the antigens showed presence of many glycan bands in the laminated layer. Conclusion: The parasite may elaborate different glycan antigens in LL to evade host immune response.

Effect of two hydatid cyst antigens on the growth of melanoma cancer in C57/black mice.

Hydatid cyst is the larval stage of Echinococcus granulosus. In previous studies inhibitory effect of this parasite on cancer cell growth in culture medium has been shown. In this study effect of hydatid cyst antigens on tumor growth in experimental animals has been investigated. Two antigens of hydatid cyst including protoscolices excretory secretory antigen and hydatid fluid absorbed on alum as adjuvant were injected to two groups of C57/black mice as case groups. Control groups were injected with only saline and alum. All mice then were injected with melanoma cells. Both antigens reduced the tumor size in mice in case groups. The difference of tumor size in mice in case groups and control group was statistically significant. In conclusion, anti-tumor effect of hydatid cyst antigens may be related to antigenic similarities which exist between hydatid cyst and cancer cells.

Parasites and immunotherapy: with or against?

Immunotherapy is a sort of therapy in which antibody or antigen administrates to the patient in order to treat or reduce the severity of complications of disease. This kind of treatment practiced in a wide variety of diseases including infectious diseases, autoimmune disorders, cancers and allergy. Successful and unsuccessful immunotherapeutic strategies have been practiced in variety of parasitic infections. On the other hand parasites or parasite antigens have also been considered for immunotherapy against other diseases such as cancer, asthma and multiple sclerosis. In this paper immunotherapy against common parasitic infections, and also immunotherapy of cancer, asthma and multiple sclerosis with parasites or parasite antigens have been reviewed.

Seroepidemiology of Toxocariasis in Children (5-15 yr Old) Referred to the Pediatric Clinic of Imam Hossein Hospital, Isfahan, Iran.

BACKGROUND: Human toxocariasis, a helminthozoonosis, is due to the migration of Toxocara species larvae into human organisms. Humans, especially children become infected by ingesting of embryonated eggs from soil, dirty hands, and raw vegetables. Seroprevalence of this infection is high in developed countries, especially in rural areas. The aim of this study was to investigate the seroepidemiology of Toxocariasis in children referred to the pediatric clinic of Imam Hossein hospital, Isfahan, Iran. METHODS: In this cross sectional study the sera of children aged 5 to 15 years old, admitted to Imam Hossein Pediatric Hospital were collected during 2013-14. Then the sera were examined for anti Toxocara canis antibodies using commercial ELISA kit. RESULTS: From 427 children, 196 (45.9%) were female and 231(54.1%) were male. 107(25.1%) were from rural and 320 (74.9%) were from urban area. Of them 129 (30.2%) were contacted with dog. One child (0.2%) had hypereosinophilia, 33 (7.7%) eosinophlia, and 6 (1.39%) were positive for T. canis IgG (two male and four female). Four of infected children with T. canis were from urban (1.25%) and two from rural areas (1.9%). There was no significant correlation between education of parents, gender, age, place of living and contact with dog with ELISA results test. CONCLUSION: Toxocariasis is prevalent in the children of Isfahan region. Results suggest a low Toxocara exposure in children in this area. Therefore, more risk factors associated with Toxocara exposure should be identified in the further investigation.

Echinococcus granulosus genotypes in Iran.

Hydatidosis, caused by Echinococcus granulosus is one of the most important zoonotic diseases, throughout most parts of the world. Hydatidosis is endemic in Iran and responsible for approximately 1% of admission to surgical wards. There are extensive genetic variations within E. granulosus and 10 different genotypes (G1-G10) within this parasite have been reported. Identification of strains is important for improvement of control and prevention of the disease. No new review article presented the situation of Echinococcus granulosus genotypes in Iran in the recent years; therefore in this paper we reviewed the different studies regarding Echinococcus granulosus genotypes in Iran.

Parasites and chronic renal failure.

Suppression of the human immune system results in an increase in susceptibility to infection by various infectious agents. Conditions such as AIDS, organ transplantation and chronic renal insufficiency (CRI) are the most important cause of insufficient immune response against infections. Long term renal disorders result in uremia, which can suppress human immune system. Parasitic infections are one of the most important factors indicating the public health problems of the societies. These infections can be more hostile and life threatening in susceptible individuals than in the normal people. In these patients some parasitic infections such as blastocystiosis, cryptosporidiosis and toxoplasmosis have been reported to be more prevalent. This review aimed to give an overview about parasitic infections in patients with renal disorders.

Hydatid Cyst Protoscolices Induce Cell Death in WEHI-164 Fibrosarcoma Cells and Inhibit the Proliferation of Baby Hamster Kidney Fibroblasts In Vitro.

Both in vitro and in vivo models have demonstrated that some parasites can interfere with tumor cell growth. The present study investigates the anticancer activity of hydatid cyst protoscolices on WEHI-164 fibrosarcoma cells and baby hamster kidney (BHK) fibroblast cells in vitro. Those above two cell types were treated with live hydatid cyst protoscolices or left untreated for control groups. After 48 h, lactate dehydrogenase (LDH) and cell counts were assayed for both treated cells and control groups. Following treatment with hydatid cyst protoscolices, cell proliferation of both cell types was inhibited, and lysis of fibrosarcoma cells increased. Based on these results, it appears that hydatid cyst protoscolices have strong anticancer activity, and additional studies are needed to further clarify the mechanisms of this activity.