Toxoplasma gondii: Seroprevalence and association with childhood brain tumors in Egypt.

BACKGROUND: Childhood brain tumors are a significant global health challenge, yet the etiology of these tumors remains elusive. While research has identified potential risk factors, recent studies have explored the involvement of infectious agents, particularly Toxoplasma gondii (T. gondii), in brain tumor development. METHODS: This study aimed to explore the prevalence of T. gondii infection in children diagnosed with brain tumors and to investigate the potential association between T. gondii infection and childhood brain tumors in Egypt. A total of 64 children with brain tumors and 92 healthy controls were enrolled in this study. Demographics and risk factors data were collected using structured questionnaires. Serological assay using ELISA technique was performed to detect anti-T. gondii antibodies in both cases and control groups. RESULTS: This study revealed a significantly higher seroprevalence of T. gondii infection in brain tumor cases (62.5 %) compared to healthy controls (38 %). Furthermore, a strong association was observed between T. gondii seropositivity and childhood brain tumors (odds ratio: 2.7). Notably, the consumption of unwashed vegetables emerged as a significant risk factor for T. gondii infection in Egypt. Analysis of T. gondii seroprevalence across different subtypes of brain tumors revealed varying rates, with glioma cases displaying a striking 100 % seroprevalence. CONCLUSIONS: These findings support the hypothesis that T. gondii infection may be a risk factor for childhood brain tumors and emphasize the need for further research in this area. The study also highlights the potential implications of control of T. gondii infection for prevention and treatment of childhood brain tumors.

Intestinal Giardiasis in Children Undergoing Upper Endoscopy for Unexplained Gastrointestinal Symptoms: Implication for Diagnosis.

BACKGROUND: Giardia lamblia is a flagellated protozoan causing diarrheal outbreaks worldwide. Microscopic stool examination is widely used. We conducted this study to explore intestinal giardiasis in children undergoing upper endoscopy for unexplained gastrointestinal symptoms. METHODS: The study included 160 children undergoing upper endoscopy for unexplained gastrointestinal symptoms (patients) and 90 children as controls. We collected stool samples for microscopic examination and ELISA coproantigen detection from all participants. We examined duodenal biopsies for patients. RESULTS: In patients, stool examination revealed Giardia in 23.8% and coproantigen detection was positive in 37.5%. Endoscopic duodenal biopsies revealed Giardia trophozoites in 5% of patients, in addition to various pathological changes. CONCLUSION: Giardiasis was significantly higher (P = 0.001) in children with unexplained gastrointestinal complaints than the controls. Diagnosis by coproantigen detection was superior to microscopic stool examination, with a sensitivity of 90.9%. Duodenal biopsies examination confirmed the infection in fewer cases but added other diagnostic information.

Seroprevalence and Genetic Characterization of Toxoplasma gondii among Children with Neurodevelopmental Disorders in Egypt.

Toxoplasma gondii is a parasite with a special predilection for the central nervous system. Toxoplasmosis's contribution to the triggering of many neurodevelopmental disorders was established. This study aimed to detect the seroprevalence and genotypes of T. gondii strains in children with neurodevelopmental disorders. The study included 180 children with neurodevelopmental disorders and 180 children in the control group. Assessment of seropositivity of Toxoplasma IgM and IgG antibodies in patients and controls was carried out. Genetic characterization of T. gondii was obtained by nested polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) technique targeting dense granule gene (GRA6). Our results showed that the overall seroprevalence of T. gondii antibodies in the patient and controls was 35.6% and 11.7%, respectively. Nested PCR showed positivity in 11.1% of the patient group for T. gondii DNA. T. gondii seropositivity rate was significantly high in patients with hydrocephalus and also in patients with epilepsy. Positive nested PCR was significantly high in children with hydrocephalus only. Genotyping using nested PCR-RFLP showed genotype I (80%) followed by atypical strains (20%) with no association with any specific clinical presentation. In conclusion, among toxoplasmosis-positive children with neurodevelopmental disorders, analysis of T. gondii GRA6 locus revealed the predominance of type I genotype followed by atypical strains.

Fluconazole as Schistosoma mansoni cytochrome P450 inhibitor: In vivo murine experimental study.

Schistosomiasis is a chronic disease caused by blood flukes of the Schistosoma spp. New approaches against this morbid infection are needed. In this study, we investigated fluconazole (FLZ) as an inhibitor of Schistosoma mansoni cytochrome P450 (S. mansoni CYP450) enzyme at different life cycle stages. We compared FLZ (10 mg/kg for two days) effects when administrated early 5 days post-infection (dpi) (Early I) and 21 dpi (Early II) versus late administration 60 dpi on S. mansoni CYP450 gene expression. These different FLZ treatment regimens were evaluated in experimentally infected mice with S. mansoni. This study showed that administration of FLZ, whether early or late during schistosomal infection, resulted in significant inhibition of S. mansoni CYP450 expression in the adult stage (P < 0.001). Early exposure to FLZ during the first week of infection significantly decreased the number of schistosomula that reached the adult stage compared to the infected control group and resulted in significant inhibition of S. mansoni CYP450 expression (P < 0.001) in the adult stage. In the Early I group, the fewest number of eggs per liver tissue gram was recorded. Our data suggested that FLZ is a S. mansoni CYP450 gene expression inhibitor with greater effect on schistosomula stages.

Activity of isoflavone biochanin A in chronic experimental toxoplasmosis: impact on inflammation.

Toxoplasma gondii is a worldwide prevalent parasite. The infection has been linked to variable inflammatory effects including neuroinflammation. Biochanin A (BCA) is an isoflavone, known for its anti-inflammatory and anti-oxidative properties. In this study, we examined the effect of BCA on the brain and liver inflammatory lesions in a murine model with chronic toxoplasmosis. Mice were divided in to six groups: non-infected control, non-infected BCA-treated, and four infected groups with Toxoplasma gondii Me49-type II cystogenic strain: infected control, BCA (50 mg/kg/day)-treated, combined BCA/cotrimoxazole-treated and cotrimoxazole (370 mg/kg/day) alone-treated. Gene expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and inducible nitric oxide synthase (iNOS) was evaluated by quantitative real-time PCR in the brain and liver tissues. In the infected control group, an upregulation of TNF-α and IL-1ß mRNA expression levels was found. However, a downregulation of iNOS expression was detected in the brain of infected control mice. In both BCA- and combined-treated groups, the brain and liver tissues showed significantly reduced inflammatory lesions compared to the infected control mice with inhibited TNF-α and IL-1ß mRNA levels. The iNOS expression levels in the brain tissues of BCA group were significantly higher than the levels of the infected control group. BCA alone or combined significantly reduced T. gondii cyst count in the brain tissues. In conclusion, the anti-inflammatory activity of BCA was demonstrated in the brain tissues of mice with chronic toxoplasmosis with decreased TNF-α and IL-1ß expression levels and increased iNOS expression levels.

Non-lethal rodent malarial infection prevents collagen-induced arthritis in mice via anti-arthritic immunomodulation.

AIMS: Immunomodulatory effects of parasitic infections on the outcomes of allergic or autoimmune disorders have been addressed in many experimental studies. We examined the effects of Plasmodium yoelii 17X NL (Py) infection on collagen-induced arthritis (CIA). METHODS AND RESULTS: Male DBA/1J mice were immunized with bovine type II collagen (IIC). Py inoculation was induced at three different time points (1, 4 weeks after or 4 weeks before the immunization). Only the inoculation at 4 weeks after IIC immunization significantly inhibited arthritis development. Non-malarial anaemia induced by phenylhydrazine hydrochloride (PHZ) did not affect arthritis development. In the infected mice, anti-IIC IgG levels were transiently reduced. In addition, splenic production of pro-arthritic cytokines (IL-17 and TNF-α) and IFN-γ decreased, whereas IL-10 production increased. Flow cytometric analysis clarified that the main IL-10 producers in Py-infected mice had the CD4+ CD25- Foxp3- phenotype, presumably Tr1 cells. CONCLUSION: We demonstrated that experimental malarial infection alleviated autoimmune arthritis via immunomodulation, suggesting the importance of malaria in the hygiene hypothesis and the significance of searching for therapeutic immunomodulatory molecules from malarial parasites.

Histopathological and ultrastructural assessment of atovaquone-proguanil hydrochloride combination in chronic murine toxoplasmosis.

Over one billion people worldwide are expected to have Toxoplasma gondii infection with anonymous health problems. Available therapies are ineffective for persistent chronic toxoplasmosis. So, there is an imperative need for effective therapies to eliminate chronic tissue stage. In this study, we aimed to assess the effect of a drug combination of atovaquone and proguanil hydrochloride in the treatment of experimental chronic toxoplasmosis. Fifty Swiss Webster mice were used in the study. Forty mice were infected with Me49 type II cystogenic Toxoplasma gondii strain and allocated into four groups: infected untreated (vehicle-administered), infected and treated with cotrimoxazole (CTX) 370 mg/kg/day, infected and treated with atovaquone (ATV) 100 mg/kg/day, and infected and treated with atovaquone/proguanil (ATV/PROG) 50 mg/kg/day. An additional group of uninfected mice was used as an uninfected control group. Drug treatment was initiated 8 weeks post-infection and continued for two weeks. All mice were sacrificed 12 weeks post-infection. Parasitological and histopathological parameters were assessed. Toxoplasma gondii cysts recovered from brain tissue homogenates of both infected untreated and ATV/PROG-treated groups were examined by scanning electron microscopy. Combined ATV/PROG treatment demonstrated a significant reduction of Toxoplasma gondii cyst count in brain tissue (a reduction rate of 84.87%) compared to untreated group (P < .001). Brain tissues obtained from ATV/PROG treated group showed reduction of inflammatory infiltrate and marked attenuation and deformation of recovered Toxoplasma gondii cysts. We conclude that ATV/PROG drug combination could offer a potential drug therapy for Toxoplasma gondii chronic cystic stage.

Validation of dried blood spots in monitoring toxoplasmosis.

Due to the growing importance of toxoplasmosis worldwide, simple methods of diagnosis are important for epidemiologic studies. Dried blood spot (DBS) is a useful tool that surpasses venipuncture. DBS-Toxoplasma testing via a finger-stick could also be used in setting where phlebotomies might not be feasible, such as worldwide prenatal and newborn screening for congenital toxoplasmosis. This study included 101 study subjects were occupationally at-risk to Toxoplasma gondii infection and 33 as controls. Serum was collected from both groups for the detection of anti-Toxoplasma IgG antibodies by ELISA as a reference gold standard test. For the occupational at-risk group, capillary finger stick derived blood was blotted onto five sets of Whatman protein saver cards. Discs were stored as four sets; three sets at 4°C and eluted 1, 2 and 3 months of storage and one set at -20°C for 3 months then eluted. Additionally, one set was eluted immediately. Anti-Toxoplasma IgG antibodies were evaluated by ELISA from DBS eluted samples and compared to matched sera. DBS elutes from discs that were freshly prepared for anti-Toxoplasma IgG showed 100% sensitivity, specificity and diagnostic accuracy. Serologic testing using DBS showed very good diagnostic accuracy under all mentioned conditions of storage. Higher stability was obtained when the blood discs stored at 4°C for 1 month and up to 3 months at -20°C, with 98.18% sensitivity, 100% specificity and 99% diagnostic accuracy. DBS-Toxoplasma testing is characterized by simplicity in performance, cost-effectiveness and the ease of handling, to store and to transport, with high diagnostic accuracy.

Insulin growth factor inhibitor as a potential new anti-schistosoma drug: An in vivo experimental study.

BACKGROUND AND OBJECTIVE: Tyrphostin "AG1024" is an insulin growth factor-1 receptor (IGF-1R) inhibitor that displayed an effect on the viability of larval and mature schistosomes in vitro. We sought to investigate the possible in vivo role of AG1024 as a potential new anti-Schistosoma drug against immature and adult stages of Schistosoma mansoni and its effect on the degree of hepatic fibrosis and insulin pathway. METHODS: The study included a control non-infected group and 5 groups of S. manosoni-infected CD-1 albino mice (20 mice each) assigned to treatment as follows: vehicle-treated, early AG1024, 30µg/100µl DMSO, IP for 10days started 30days post-infection (dpi), early praziquantel (PZQ), 500mg/kg orally for 2days (30dpi), late AG1024 (60dpi), and late PZQ (60dpi). All mice were sacrificed 12 weeks post-infection. Parasitological, chemical and histopathological parameters were studied. Immunohistochemistry of TGF-ß and GLUT4 in liver sections was done to further evaluate the effect of AG1024 on the degree of hepatic fibrosis and insulin signaling pathway, respectively. RESULTS: Early administration of AG1024 (30dpi) resulted in significant reduction of hepatic and intestinal tissue egg count with a reduction of 79.99% and 89.1% respectively. Late administration of AG1024 (60dpi) led to 77.78% reduction of intestinal eggs count; however, hepatic egg count wasn't reduced significantly. No reduction in worm burden was recorded for both administration regimens. Both regimens lead to significant decrease of both ALT and AST, mean hepatic granuloma diameter but an increase in fibrosis percentage (65.2% and 55% respectively). Both early and late treatment with AG1024 showed a significant increment of TGF-ß expression by 71.4% and 39.3%, respectively (p<0.0001) compared to PZQ-treated and infected non-treated groups. Hepatic GLUT4 expression was significantly decreased compared to infected non-treated group (p<0.001) and the corresponding PZQ-treated group. CONCLUSION: Early AG1024 administration induced more significant results compared to early PZQ with a promising activity against egg production and subsequent reduction of tissue egg load rather than direct schistosomicidal effect; however, it induced granuloma fibrosis, TGF-ß expression, and disrupted the insulin signaling pathway.

Tuberculosis/toxoplasmosis co-infection in Egyptian patients: A reciprocal impact.

OBJECTIVE: To assess the concurrent toxoplasmosis infection in Egyptian TB patients and the impact of each infection on the other in terms of increased severity of TB or reactivation of latent Toxoplasma infection. METHODS: Three hundred suspected pulmonary TB cases were initially screened for TB using direct Ziehl Neelsen staining and Lowenstein Jensen culture of their sputa. Rifampicin resistance was detected by Xpert MTB/RIF assay. Control group of 30 age and sex-matched healthy individuals negative for TB was included for comparison. All subjects were further assessed for serum levels of anti-Toxoplasma IgG antibodies and malondialdehyde (MDA). RESULTS: Forty three confirmed TB-infected patients including 10 (23.3%) rifampicin-resistant patients were detected. Associated toxoplasmosis was found to be significantly higher among TB patients (OR = 2.709; 95% CI: 1.034-7.099; P<0.05) and among rifampicin sensitive than rifampicin resistant TB patients (OR=0.213; 95% CI: 0.048-0.951; P < 0.05). Serum levels of anti-Toxoplasma IgG antibodies and MDA were significantly higher among TB patients than the control group. Furthermore, serum level of MDA was significantly higher among TB/Toxoplasma co-infected patients as compared to toxoplasmosis free-TB patients. Strong positive correlation was detected between serum levels of anti-Toxoplasma IgG and MDA in TB patients (r = 0.75, P = 0.001). CONCLUSIONS: Among pulmonary TB Egyptian patients, there is a considerable prevalence of toxoplasmosis. Severity of pulmonary tuberculosis could be increased by Toxoplasma co-infection.

Possible antifibrotic effect of GDC-0449 (Vismodegib), a hedgehog-pathway inhibitor, in mice model of Schistosoma-induced liver fibrosis.

Liver fibrosis is a pathological process complicating schistosomiasis. It is an active process of continuous extracellular matrix accumulation. In Egypt, schistosomiasis re-infection is a continuing problem especially in rural areas. In this study we examined the antifibrotic effect of GDC-0449 (Vismodegib), a hedgehog-pathway inhibitor as a new molecular target for Schistosoma-induced liver fibrosis, in addition to exploring its effect as antischistosomal drug. The effect of GDC-0449 alone or combined with Praziquantel was tried experimentally in infected mice with Schistosoma mansoni. Fifty CD-1 Swiss female albino mice were used, forty mice were infected with Schistosoma mansoni cercariae. Animals were grouped into five groups; uninfected control, infected untreated, infected treated with Praziquantel (500mg/kg/day) for two days, infected treated with GDC-0449 (40mg/kg/day) for seven days, and infected treated with combined Praziquantel and GDC-0449. Parasitological and chemical parameters, hydroxyproline level and liver granuloma were assessed. Liver fibrosis was reduced significantly evidenced by reduced hydroxyproline levels [P<0.01 for combined (Praziquantel/GDC-0449) treatment groups, P<0.001 for GDC-0449-treated group]. Also, histopathological examination of liver tissues revealed that the mean diameter of granulomas was statistically reduced (P=0.001) with a reduction rate of 24.4% on treatment with GDC-0449. In GDC-0449/Praziquantel combined treatment group, number and mean diameter of the granulomas were reduced significantly P<0.001, and P=0.001 respectively. No antischistosomal effect was recorded for GDC-0449 in this study.

Anti-Toxoplasma antibodies in Egyptian rheumatoid arthritis patients.

OBJECTIVE: To assess seroprevalence of anti-Toxoplasma gondii antibodies; both IgG and IgM in Egyptian rheumatoid arthritis (RA) patients versus a non-RA group and to compare anti-Toxoplasma antibodies seroprevalence among RA patients receiving traditional treatment and RA patients treated with biologic drug. METHODS: 60 RA patients and 60 healthy controls were enrolled in the study. Patients were categorized into two groups: one group included 30 patients receiving disease modifying anti-rheumatic drugs (DMARDs), while the other group included 30 patients receiving biologic agent, infliximab, a TNF-α antagonist. Serum samples of all investigated persons were examined for anti-Toxoplasma antibodies. RA activity markers including rheumatoid factor, anti-cyclic citrullinated protein antibodies, C reactive protein, ESR in addition to disease activity score 28 (DAS28) of RA patients were also evaluated to explore their association with Toxoplasma seropositivity. RESULTS: Anti-Toxoplasma IgG antibodies were detected among 46/60 RA patients (76.7%) versus 29/60 controls (48.3%), (p = 0.001). Anti-Toxoplasma IgG titre was higher among RA group [median, (range) = 232.940 (8.949-653.242) IU/ml] than among controls [median, (range) = 68.820 (2.450-318.945) IU/ml], (p < 0.001). No difference was detected among RA patients either on traditional or biologic treatment regarding anti-Toxoplasma IgG antibodies. No positive anti-Toxoplasma IgM was detected. A positive correlation was detected between anti-Toxoplasma IgG titre and disease activity markers. CONCLUSION: Higher seroprevalence of anti-Toxoplasma IgG antibodies among RA patients compared to controls reflects an association between latent Toxoplasma infection and RA. Our findings support previous studies and necessitate future large-scale studies to elucidate the exact role of Toxoplasma whether a trigger of autoimmunity in RA or an effect of immunosuppression.

Evaluation of the efficacy of oral ivermectin in comparison with ivermectin-metronidazole combined therapy in the treatment of ocular and skin lesions of Demodex folliculorum.

OBJECTIVE: To evaluate the efficacy of ivermectin and combined ivermectin-metronidazole therapy in the treatment of ocular and skin lesions of Demodex folliculorum. METHODS: One hundred twenty patients with skin lesions and anterior blepharitis, whose infestation was treatment-resistant and who had a Demodex count >5 mites/cm² for skin lesions or ≥ 3 mites at the root of each eyelash, were recruited. The treatment regimens were ivermectin and ivermectin-metronidazole combined therapy. We enrolled 15 patients from each of four groups for each treatment regimen. Demodex was detected by standardized skin surface biopsy for skin lesions. Three eyelashes from each affected lower eyelid were epilated and examined. The study subjects were followed-up once a week for four visits. RESULTS: There was a difference in the mite count between the subgroups taking ivermectin and combined therapy during all follow-up visits. At the last visit, in the combined therapy subgroup, 1.7% of patients showed no clinical improvement, 26.7% showed a marked clinical improvement, and 71.6% showed complete remission. In those on the ivermectin regimen, 27 patients had a mite count >5 mites/cm², 21.7% showed no clinical improvement, 33.3% showed a marked improvement, and 45% showed complete remission. CONCLUSIONS: Combined therapy was superior in decreasing the D. folliculorum count in all groups and in reducing the mite count to the normal level in rosacea and in anterior blepharitis. On the other hand, the two regimens were comparable in reducing the mite count to the normal level in acne and peri-oral dermatitis lesions.