Genetic Diversity of Toxoplasma gondii by Serological and Molecular Analyzes in Different Sheep and Goat Tissues in Northeastern Iran

Background

Toxoplasmosis is a parasitic disease caused by compilation protozoan agent Toxoplasma gondii, leading to significant financial and quality-adjusted life-year losses. Overcooked or raw meat consumption has been a considerable transmission route. The present study was conducted to determine the seropositivity rate of T. gondii in sheep and goats by serological and molecular tests and genotyping of obtained isolates in northeast Iran.

Methods

Blood and tissue samples (diaphragm, heart) of 296 animals (including 168 sheep and 128 goats) were collected from the slaughterhouse in Quchan Country from august 2016 to April 2017. Modified agglutination test (MAT) and the PCR method performed to detect parasite DNA on tissues.PCR-RFLP method of GRA6 gene was used to determine the genotype of T. gondii. In addition, sequencing analysis was performed to evaluate the Toxoplasma type strains.

Results

Serum positive for MAT results were found in 27.4% of sheep and 23.4% of goats. Positive PCR of B1 gene results in diaphragm and heart tissues of sheep and goats was 47.8% and 26.1%, 40% and 23.3%, respectively. PCR of GRA6 gene results were positive in 10 samples that RFLP technique results using MseI enzyme revealed genotype I. Sequencing and phylogenetic analysis revealed DNA of all samples was closely related to Toxoplasma type I.

Conclusion

Concerning the high seropositivity rate of toxoplasmosis, undertaking an appropriate preventive program for reducing the prevalence of T. gondii infection by raw or undercooked meat consumption of livestock is recommended. Our study supports the notion that these animals' consumption of raw and undercooked meat can be a probable source of human toxoplasmosis.

Chronic Toxoplasma gondii Infection Potentiates Parkinson’s Disease Course in Mice Model

Background:

Toxoplasma gondii is a neuroinvasive protozoa pathogen that could manipulate its intermediate host's behavior. However, the possible link between T. gondii infection and the development of neurodegenerative disorders such as Parkinson’s disease (PD) has been proposed, we tested the hypothesis that in chronic toxoplasmosis neuroinflammation, and molecular mediators potentiate behavioral-cognitive impairments in BALB/c mice with PD.

Methods:

To establish chronic toxoplasmosis by Tehran strain, cysts of T. gondii were injected intraperitoneally into BALB/c mice in Kerman, Iran in 2019. To induce the PD model, mice (BALB/c) were treated with Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The behavioral experiments such as anxiety and motor coordination were performed using the Open field and Rotarod tests. Additionally, we investigated the contribution of Toxoplasma-induced neuroinflammation, and behavioral-cognitive impairments in the PD mice model.

Results:

Chronic toxoplasmosis caused PD-like symptoms and induced various behavioral changes in infected BALB/c mice. In T. gondii infected+MPTP treated group, T. gondii infection could potentiate PD in infected mice receiving MPTP and caused remarkable dysfunction in motor coordination and change in anxiety and depression-like behaviors similar or more severe than PD group.

Conclusion:

Chronic T. gondii infection exacerbates pathological progression of PD in BALB/c mice brain by promoting neuroinflammation, and behavioral changes establishing.

Prophylactic Activity of Biogenic Selenium Nanoparticles Against Chronic Toxoplasma gondii Infection

BACKGROUND

Studies showed that biogenic selenium nanoparticles (SeNPs) have a number of pharmacological properties, such as antimicrobial ones.

OBJECTIVE

The present investigation assesses the efficacy of biogenic selenium nanoparticles (SeNPs) as a new patent against latent toxoplasmosis in a mice model.

METHODS

Male BALB/c mice were orally treated with SeNPs at the doses of 2.5, 5, 10 mg/kg once a day for 14 days. On the 15th day, the mice were infected with the intraperitoneal inoculation of 20-25 tissue cysts from the Tehran strain of Toxoplasma gondii. The mean numbers of brain tissue cysts and the mRNA levels of TNF-α, IL-12, IL-10, IFN-γ, and inducible nitric oxide synthase (iNOS) in mice of each tested group were measured. Moreover, serum clinical chemistry factors in treated mice were examined to determine the safety of SeNPs.

RESULTS

The mean number of the brain tissue cysts was significantly (P<0.001) decreased in mice treated with SeNPs at doses 2.5 (n=37), 5 (n=11), and 10 mg/kg (n=3) based on a dose dependent manner compared with the control group (n=587). The mRNA levels of IFN-γ, TNF-α, IL-12, and iNO were significantly increased in mice treated with SeNPs at the doses 10 mg/kg compared with control subgroups (p<0.05). No significant variation (p>0.05) was observed in the clinical chemistry parameters among the mice in the control subgroups compared with groups treated with SeNPs.

CONCLUSION

The results of the present study showed a new patent in the treatment of toxoplasmosis; so that taking the biogenic selenium nanoparticles in concentrations of 2.5-10 mg/kg for 2 weeks was able to prevent severe symptoms of the toxoplasmosis in a mice model. This indicated the prophylactic effects of SeNPs with no considerable toxicity against latent toxoplasmosis. However, more studies are required to elucidate the correct anti-Toxoplasma mechanisms of SeNPs.

Molecular, Morphological, and Spatial Study of Galba schirazensis (Pulmonata, Lymnaeidae) from Southeastern Iran

Background:

Snails of the genus Galba are the intermediate hosts of Fasciola species, the etiological agents of liver fluke disease, fascioliasis. A genetically different but morphologically very similar species in the genus, G. schirazensis, is sympatrically distributed with G. truncatula in some regions of the world. We aimed to investigate the occurrence of G. schirazensis in Kerman province, Iran and to characterize genetically G. schirazensis specimens from southeast Iran.

Methods:

Field-collected snails from four localities in Jiroft, Bam and Faryab, Kerman province, southeastern Iran were studied. Hydrological variables including temperature and pH were recorded for each habitat. Each specimen was identified using morphological as well as conchological characteristics. Genetic characterization was performed using PCR-sequencing followed by phylogenetic analyses on nuclear ITS2 as well as mitochondrial cox1 gene fragments. MaxEnt software was used to predict the most appropriate ecological niches for the targeted species.

Results:

G. schirazensis was found in 4 out of 28 locations. One ITS2 and two cox1 haplotypes were detected among G. schirazensis populations from the four localities. Habitat study showed that G. schirazensis thrives in habitats with alkaline pH. G.schirazensis from South America were clustered with specimens from Bam, Kerman, Iran; however, north Iranian isolates of G. schirazensis were strongly correlated with specimens from Jiroft and Faryab. MaxEnt model for the most appropriate ecological niches of the targeted species predicted environmental suitability for this species in western Africa as well as coastal areas in north and southwestern Africa.

Conclusion:

G. schirazensis is frequently present in southern areas of Kerman Province. At least two genetically different haplotypes are present in southeastern Iran.

Biogenic selenium nanoparticles target chronic toxoplasmosis with minimal cytotoxicity in a mouse model

Introduction. Nanoparticles (NPs) have numerous biological benefits due to their large surface-volume ratio and convenient entry into cells compared to other particles. Previous research has shown the antimicrobial properties of biogenic selenium NPs (SeNps) and their effects on cellular immunomodulatory cytokines that play a key role in controlling infections.Aim. This study aimed to evaluate the therapeutic effects of SeNPs against chronic toxoplasmosis in mice.Methodology. Infected mice with Toxoplasma gondii (Tehran strain) were orally treated with SeNPs at doses of 2.5, 5 and 10 mg kg^-1 once a day for 14 days. On the fifthteenth day, the mean number of brain-tissue cysts and the mRNA levels of TNF-α, IL-12, IL-10, IFN-γ and inducible nitric oxide synthase (iNOS) in the mice of each group were recorded. Moreover, serum clinical chemistry factors in the treated mice were examined to determine the safety of SeNPs.Results. The mean number of tissue cysts was significantly (P<0.001) decreased in mice treated with SeNPs in a dose-dependent manner compared with the control group. The mRNA levels of inflammatory cytokines were significantly increased in mice treated with SeNPs at a dose of 10 mg kg^-1 compared with the control subgroup (P<0.05). No significant variation (P>0.05) observed in clinical chemistry parameters among the mice in the control subgroup compared with those treated with SeNPs.Conclusion. The findings demonstrated the therapeutic effects of SeNPs with no considerable toxicity against latent toxoplasmosis in the mouse model. Nevertheless, further studies are obligatory to reveal the exact anti-Toxoplasma mechanisms of SeNPs.

Propranolol efficacy as a novel adjuvant for immunization against Toxoplasma gondii tachyzoites

Severe or lethal damages, caused by Toxoplasma gondii infection in congenital cases and immunocompromised patients implies the necessity for development of a vaccine and an appropriate adjuvant would be needed to elicit a protective Th1 biased-immune response. The adjuvant activity of propranolol was surveyed and compared with alum by immunization of BALB/c mice with protein components of T. gondii tachyzoites. Five groups of BALB/c mice were immunized with phosphate buffered saline (negative control), Toxoplasma lysate antigen (TLA), alum plus TLA, Propranolol plus TLA, and alum, propranolol and TLA. Immunization efficacy was evaluated by lymphocyte proliferation and DTH tests, challenge with live tachyzoites, IFN-γ production by spleen cells, serum TNF-α concentration and anti- Toxoplasma total IgG, IgG1 and IgG2a measurements. Mice of the PRP-TLA group induced significantly more IFN-γ and TNF-α production and lymphocyte proliferation than other groups. This group of mice also showed more anti-T. gondii IgG2a and DTH responses and showed a significantly increased survival time after challenge. These findings indicate that propranolol as an adjuvant in combination with TLA, may enhance cellular immunity against T. gondii.

Toxoplasma gondii Infection Promotes Neuroinflammation Through Cytokine Networks and Induced Hyperalgesia in BALB/c Mice

We hypothesized that in Toxoplasma gondii infection, communication among immune cells promotes neuroinflammation through cytokine networks and induces pain sensitivity under conditions of neuropathic pain. The animal model of Toxoplasma infection was established by the intraperitoneal inoculation of 20-25 tissue cysts from Tehran strain of T. gondii to BALB/c mice. Amitriptyline (20 mg/kg, i.p., 1/day) administrated to animals for 7 days before behavioral tests. Pain behavioral tests including tail flick, hot plate, and formalin test were evaluated in all the groups. The mRNA levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 were examined by real-time PCR. Results revealed that T. gondii induce hyperalgesia in the infected mice, whereas amitriptyline showed a promising effect against the hyperalgesia induced by Toxoplasma infection. The mRNA levels of the aforementioned cytokines significantly (P < 0.05) increased in the infected mice compared to the uninfected ones. Obtained findings suggested that T. gondii infection could promote neuroinflammation through cytokine networks and induced hyperalgesia in BALB/c mice, whereas amitriptyline as an analgesic drug reverses them.

The possible association between Toxoplasma gondii infection and risk of anxiety and cognitive disorders in BALB/c mice

There are conflicting reports concerning the association of Toxoplasma gondii infection with increased risk of mental disorders. This investigation will provide a good understanding about defining the possible association between T. gondii exposure and risk of anxiety and cognitive alterations. Besides, a secondary objective of this study was to determine the effect of pioglitazone administration on the possible alterations induced by T. gondii exposure. Male BALB/c mice were used for this study. The animal model of Toxoplasma infection was established by the intraperitoneal inoculation of 20-25 tissue cysts from Tehran strain of T. gondii. Pioglitazone (20 mg/kg, i.p.1/day) was administered to the animals for 2 weeks before behavioural tests. Behavioural tests including open-field, elevated plus-maze and passive avoidance learning were evaluated in the groups. Since cytokines were implicated as a contributing factor for mood disorders, the mRNA levels of TNF-α, IL-1β, IL-6 as well as inducible nitric oxide synthase (iNOs) were examined by real-time PCR. Findings demonstrated that T. gondii caused anxiety-like symptoms and impaired cognitive functions of the infected BALB/c mice, whereas pioglitazone, a peroxisome proliferator-activated receptor agonist, showed a promising effect against the cognitive impairments induced by Toxoplasma infection. The results also revealed that the mRNA levels of the aforementioned cytokines were significantly (p < 0.05) increased in the infected mice compared to the uninfected BALB/c ones. Pioglitazone can be offered as a potential neuroprotective agent in the treatment of patients with T. gondii infection that manifests anxiety and cognitive impairments; however, further studies are needed to clarify the exact mechanisms.

Toxoplasma gondii Infection Potentiates Cognitive Impairments of Alzheimer's Disease in the BALB/c Mice

This study tests the hypothesis that in chronic Toxoplasma gondii infection communication among immune cells promotes neuroinflammation through cytokine networks and potentiate cognitive impairments in BALB/c mice with Alzheimer's disease (AD). The animal model of Toxoplasma infection was established by the intraperitoneal inoculation of 20-25 tissue cysts from the Tehran strain of T. gondii . We injected amyloid-beta 1-42 peptide (Aβ_1-42, 1 and 2 μl) into the hippocampus of BALB/c mice to establish an animal model of AD. The behavioral experiments such as spatial learning and memory were performed using the Morris water maze test. The mRNA levels of TNF-α, IL-1β, IFN-γ, and inducible nitric oxide synthase (iNOS) were examined by real-time PCR. We found that T. gondii infection caused AD-like symptoms and impaired learning and memory functions of the infected BALB/c mice. We also found that in Toxoplasma infection + Aβ_1-42 (1 μl) group, T. gondii infection could potentiate AD in infected mice receiving subdoses of Aβ_1-42 (1 μl) and caused considerable impairment in learning and memory functions similar to AD group. Comparison of the results demonstrated that mRNA levels of IL-1β, TNF-α, IFN-γ, and iNOS significantly (P < 0.001) increased in T. gondii + Aβ_1-42 (1 μl) in comparison with the other tested groups. The obtained results showed that chronic T. gondii infection communication among immune cells promotes neuroinflammation through cytokine networks and induces pathological progression of AD in the mice brain, whereas the presence of neuroanatomical Toxoplasma tissue cysts in the brain could also affect the behavioral functions in T. gondii -infected mice.

High resolution melting technique for molecular epidemiological studies of cystic echinococcosis: differentiating G1, G3, and G6 genotypes of Echinococcus granulosus sensu lato

Reliable and rapid genotyping of large number of Echinococcus granulosus sensu lato isolates is crucial for understanding the epidemiology and transmission of cystic echinococcosis. We have developed a method for distinguishing and discriminating common genotypes of E. granulosus s.l. (G1, G3, and G6) in Iran. This method is based on polymerase chain reaction coupled with high resolution melting curve (HRM), ramping from 70 to 86 °C with fluorescence data acquisition set at 0.1 °C increments and continuous fluorescence monitoring. Consistency of this technique was assessed by inter- and intra-assays. Assessment of intra- and inter-assay variability showed low and acceptable coefficient of variations ranging from 0.09 to 0.17 %. Two hundred and eighty E. granulosus s.l. isolates from sheep, cattle, and camel were used to evaluate the applicability and accuracy of the method. The isolates were categorized as G1 (93, 94, and 25%), G3 (7, 4, and 4%), and G6 (0, 2, and 71%) for sheep, cattle, and camel, respectively. HRM results were completely compatible with those obtained from sequencing and rostellar hook measurement. This method proved to be a valuable screening tool for large-scale molecular epidemiological studies.