Brain -cyst-driven genes expression in Toxoplasma Gondii Tehran strain: a parasitic-immunogenicity assessment by dint of RNA-Seq.

Toxoplasma gondii (T. gondii) is an obligate intracellular parasite of warm-blooded vertebrates. At present, High-throughput RNA sequencing analysis have made it possible to determine the role of effective genes in host immune response. The aim of the present study is to global transcriptome analysis of the brain of mice infected with T. gondii Tehran strain for the first time and also to evaluate the expression of effective genes in the chronic form of infection. RNA was extracted from the samples and the library was prepared and sequenced using the IlluminaNovaSeq 6000 system. After analyzing gene expression changes, the results were confirmed by real-time method. We found 125 genes that were significantly differentially expressed between infected and non-infected samples (p < 0.0005). Gene ontology analysis revealed that the expression of many genes is critical for pathways such as T cell receptor signaling pathway, Natural Killer cell mediated cytotoxicity, Lysosome and Apoptosis of the host. As infection with Tehran strain leads to chronic infection in mice, therefore, we investigated the genes effective in creating the chronic form of Toxoplasma infection. The comparative analysis of genes showed increases in the expression of genes ctla4, ccl4, cd3e, c3, lcn2, gbp5, usp18, cyba, tap1 and samhd1 in the in the infected sample, which highlights their role in causing chronic infection. RNA-seq provides a valuable tool for analyzing host transcriptomes, better understanding the parasite-host interaction, and developing future drug and vaccine targets.

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.

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.

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.

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.

Considerable Genetic Diversity of Trichomonas vaginalis Clinical Isolates in a Targeted Population in South of Iran.

BACKGROUND: The present study aimed to characterize genetically and to compare the most frequently occurring strains of Trichomonas vaginalis isolated from southern Iran. METHODS: Totally, 150 vaginal swab and urine specimens were collected from symptomatic and asymptomatic women from May 2012 to Jun 2013. This study implemented a sensitive and reliable PCR-restriction fragment length polymorphism (RFLP) typing method on the actin gene. Moreover, one representative sample of each identified genotype was subjected to sequencing. RESULTS: Twenty-four T. vaginalis isolates were positive and 6 distinct electrophoretic patterns (H, E, G, I, M, N) were identified. Genotypes H and I were found to be more prevalent (50 and 37.5%) in Kerman and Shiraz, respectively. The phylogenetic analysis showed that two isolates were located as a separated clade with the other T. vaginalis isolates. CONCLUSION: The obtained findings showed a considerable genetic polymorphism of clinical isolates from the population studied. More studies may be warranted in future as to unveiling any possible links between a given genotype/cluster and pathogenic behavior of T. vaginalis.

Morphometric and Molecular Study of Fasciola Isolates from Ruminants in Iran.

OBJECTIVE: The purpose of the present study was morphometric and molecular characterization of Fasciola isolates from ruminants in Iran. METHODS: Flukes were collected from the livers of 54 naturally infected sheep and cattle. The proportion of body length to width (L/W) of each fresh fluke was measured using a digital caliper. We employed receiver operating characteristic (ROC) curve analysis to explore the reliability of L/W for differentiating the two species. Polymerase chain reaction (PCR)-sequencing was performed on ribosomal Internal Transcribed Spacers (ITS) and mitochondrial cytochrome c oxidase subunit 1 (cox1) genes. The sequences were then analyzed and phylogenetic relationships were investigated. RESULT: Forty-eight out of 54 isolates (88.9%) were identified as F. hepatica and four isolates (7.4%) as F. gigantica. All the sheep isolates were F. hepatica, while 4 out of 10 cattle were infected with F. gigantica. The morphometric study revealed an L/W ratio of 1.2 to 6.5 in Fasciola isolates with significantly higher L/W ratio in F. gigantica (p<0.00). According to the ROC curve analysis, the L/W value of 3.55 was regarded as the critical value to discriminate between the two species. CONCLUSIONS: Findings of the present study indicate the presence of both Fasciola species in southeastern Iran. The phylogenetic analysis revealed two different clades representing F. hepatica and F. gigantica. The two isolates in this study were described as Fasciola sp. The mitochondrial DNA of these isolates were similar to F. hepatica, while their ITS fragments were identical to F. gigantica.

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 (Aß1-42, 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-1ß, 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 + Aß1-42 (1 µl) group, T. gondii infection could potentiate AD in infected mice receiving subdoses of Aß1-42 (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-1ß, TNF-α, IFN-γ, and iNOS significantly (P < 0.001) increased in T. gondii + Aß1-42 (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.

Acetylcholinesterase Inhibitor Improves Learning and Memory Impairment Induced by Toxoplasma gondii Infection.

BACKGROUND: Here, we established the mouse models of chronic toxoplasmosis by T. gondii Tehran strain to provide a good understanding about defining the possible association between T. gondii exposure and learning and memory impairments. Moreover, as secondary objective of the present study, we hypothesized whether administration of an acetylcholinesterase (AChE) inhibitor could reduce learning and memory impairments induced by T. gondii infection. METHODS: Twenty-four male BALB/c mice were used to establishment of latent toxoplasmosis. The animal model of Toxoplasma infection was established by the intraperitoneal inoculation of 20-25 tissue cysts from Tehran strain of T. gondii. Donepezil (2 mg/kg) an AChE inhibitor to treat Alzheimer disease was injected intraperitoneally once a day for two weeks starting from post-infection day 90. Morris water maze (MWM) task was used to assay spatial learning and short term spatial memory in all groups. One-way ANOVA with Tukey's post-hoc test was used to assess differences between experimental groups. P<0.05 was considered statistically significant. RESULTS: Toxoplasma infection impaired spatial leaning and short term spatial memory of the infected BALB/c mice, whereas donepezil, an AChE inhibitor, improved impairments induced by Toxoplasma infection. CONCLUSION: T. gondii infection through increasing AChE reduces the level of Acetylcholine (Ach) and consequently affects learning and memory activity in infected hosts, whereas, donepezil as an AChE inhibitor improves these impairments by restoring ACh levels at synapses of neurons in brain.

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)-1ß, 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-1ß, 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.

Scolicidal effects of biogenic selenium nanoparticles against protoscolices of hydatid cysts.

Cystic echinococcosis (hydatid cyst, CE) as a zoonotic parasitic infection caused by the larval stage of the dog tapeworm Echinococcus granulosus is still an important economic and public health concern in the world. One of the treatment options for CE is surgical removal of the cysts combined with chemotherapy using albendazole and/or mebendazole before and after surgery. Currently, many scolicidal agents, which have some complications, have been used for inactivation of the cyst contents. Therefore the development of new scolicidal agents with low side effects and more efficacies is an urgent need for surgeons. The present study was aimed to investigate the in vitro scolicidal effect of selenium nanoparticles biosynthesized by a newly isolated marine bacterial strain Bacillus sp. MSh-1 against protoscoleces of E. granulosus. Protoscolices were aseptically aspirated from sheep livers having hydatid cysts. Various concentrations (50-500 µg/ml) of Se NPs (in size range of about 80-220 nm) were used for 10-60 min. Viability of protoscoleces was confirmed by 0.1% eosin staining. The results indicated that biogenic Se NPs at all concentrations have potent scolicidal effects especially at concentrations 500 and 250 µg/ml after 10 and 20 min of application, respectively. In conclusion, the findings of present study proven that Se NPs have potent scolicidal effects, therefore may be used in CE surgery. However, the in vivo efficacy of these NPs remains to be explored.

Molecular and serological detection of acute and latent toxoplasmosis using real-time PCR and ELISA techniques in blood donors of rafsanjan city, iran, 2013.

BACKGROUND: The differentiation between acute and latent forms of the Toxoplasma gondii (T. gondii) infection is still considered as a complicated issue. This study was aimed to elucidate the status of infection in the blood donors and the probable importance of blood transfusion in the transmission of the infection through detecting both immunological and genetic markers of acute and latent infection. METHODS: Totally 235 blood samples from blood donors were collected. The levels of anti-T. gondii IgG and IgM antibodies were examined by specific ELISA kits. cDNA were synthesized from total extracted mRNA molecules from the serum samples and SAG1 gene, specific for tachyzoite form, were amplified using Real-Time PCR technique. Demographic information of study subjects including their gender, age, job, and habitat were recorded. RESULTS: Out of 235 serum samples, 80 (34.04%) and 4 (1.71%) were positive regarding anti-T. gondii IgG and IgM antibodies, respectively. Real-Time PCR results showed that 14 out of 200 (6.97%) of blood donor had mRNA molecules of SAG1 gene. The positive results of Real-Time PCR of SAG1 in female gender and housekeepers were significantly higher than those of male gender and other job categories. CONCLUSION: The prevalence of chronic and acute infection is high in Iranian blood donors. Additionally, evaluation of antibodies could not be reliable, because several donors negative for anti-T. gondii IgM antibodies had detectable SAG1 mRNA molecules. Hence, it seems that molecular diagnostic tests are essential to detect acute infections.

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.

Prevalence of anti-Toxoplasma gondii antibodies in sport horses from Qazvin, Iran.

In the present study, the prevalence of antibodies to Toxoplasma gondii in sport horses of Qazvin was examined using modified agglutination test (MAT). On 52 horse sera totally examined for anti-Toxoplasma antibodies, 37 horses (71.2%) were seropositive by MAT. Results of the present study showed a high rate of Toxoplasma infection in horses in Qazvin area. More comprehensive study on equine toxoplasmosis is recommended.

Feline immunodeficiency virus, feline leukemia virus and Toxoplasma gondii in stray and household cats in Kerman-Iran: seroprevalence and correlation with clinical and laboratory findings.

This study was carried out to determine the seroprevalence of feline leukemia virus (FeLV), feline immunodeficiency virus (FIV) and Toxoplasma gondii (T. gondii) infection among stray and owned cats in southeastern Iran and to identify the influence of age, sex, lifestyle, health status, and laboratory findings on seropositivity. The overall infection rate for FIV, FeLV, and T. gondii was 19.2%, 14.2%, and 32.1% respectively. Results of the multivariate logistic regression analysis showed that old adults more likely to be seropositive than juveniles for FIV, FeLV, and T. gondii (adjusted odds ratios [ORs], 1.84, 1.56, and 2.57 respectively). Anemic and diseased cats ([ORs], 6.62 and 0.9) were at a greater risk of testing positive for FeLV. Male cats were 4.91 times as likely to have FIV as were female and hyperglobulinemia was significantly more prevalent in FIV-infected cats ([ORs], 3.4). In conclusion, FIV and FeLV seem to be endemic in Iran and retroviral-associated immunosuppression may be a risk factor for active toxoplasmosis in infected cats.