Mehdi Arshadi1, Lame Akhlaghi1, Ahmad Reza Meamar1, Leila Alizadeh Ghavidel2, Kamal Nasiri2, Mahmoud Mahami-Oskouei3, Farideh Mousavi2, Zahra Rampisheh4,5, Majid Khanmohammadi1, Elham Razmjou1. 1. Department of Parasitology and Mycology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. 2. Department of Ophthalmology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran. 3. Department of Parasitology and Mycology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran. 4. Preventive Medicine and Public Health Research Center, Iran University of Medical Sciences, Tehran, Iran. 5. Department of Community Medicine, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
Abstract
BACKGROUND: Our goal was to use molecular techniques to verify and characterise clinical diagnoses of ocular toxoplasmosis. Clinical cases were evaluated against IgM and IgG Toxoplasma antibodies, and IgG avidity was tested. B1 gene was assessed for molecular detection, and multi-locus genotyping were conducted to type Toxoplasma infections. METHODS: A cross-sectional study was conducted in 33 patients with suspected active ocular toxoplasmosis. Patients were examined by an ophthalmologist and clinical manifestations were recorded. Toxoplasma gondii IgG and IgM from serum samples were analysed by chemiluminescence immunoassay and ELISA. Acute vs chronic infection was evaluated by IgG avidity testing. Molecular diagnosis of T. gondii infection targeted the B1 gene, and the T. gondii genotype was determined by amplification of the GRA6, SAG2, SAG3, BTUB and APICO loci. The correlation of age, gender, occupation, education, contact with cats or soil, and the consumption of undercooked meat with the incidence of ocular toxoplasmosis was evaluated. RESULTS: Twenty-eight patients (84.8%) were seropositive, two (6%) were both IgG and IgM positive, while one (3%) showed IgG avidity <40%. Molecular testing confirmed toxoplasmosis in 27 patients (81.8%). Chorioretinal scarring (p=0.014) and posterior uveitis (p=0.004) was significantly associated with ocular toxoplasmosis patients. Multi-locus genotyping showed genotype I. Ocular toxoplasmosis showed no significant correlation with gender, age, behaviours, occupation or education. CONCLUSION: Clinical manifestations, serological and molecular detection of Toxoplasma were highly correlated in the diagnosis of ocular toxoplasmosis. Genotype I was predominant in ocular toxoplasmosis in northwest Iran. A larger comparative study should be conducted to provide a broader view of the molecular epidemiology of T. gondii genotypes and its role in toxoplasmosis.
BACKGROUND: Our goal was to use molecular techniques to verify and characterise clinical diagnoses of ocular toxoplasmosis. Clinical cases were evaluated against IgM and IgG Toxoplasma antibodies, and IgG avidity was tested. B1 gene was assessed for molecular detection, and multi-locus genotyping were conducted to type Toxoplasma infections. METHODS: A cross-sectional study was conducted in 33 patients with suspected active ocular toxoplasmosis. Patients were examined by an ophthalmologist and clinical manifestations were recorded. Toxoplasma gondii IgG and IgM from serum samples were analysed by chemiluminescence immunoassay and ELISA. Acute vs chronic infection was evaluated by IgG avidity testing. Molecular diagnosis of T. gondiiinfection targeted the B1 gene, and the T. gondii genotype was determined by amplification of the GRA6, SAG2, SAG3, BTUB and APICO loci. The correlation of age, gender, occupation, education, contact with cats or soil, and the consumption of undercooked meat with the incidence of ocular toxoplasmosis was evaluated. RESULTS: Twenty-eight patients (84.8%) were seropositive, two (6%) were both IgG and IgM positive, while one (3%) showed IgG avidity <40%. Molecular testing confirmed toxoplasmosis in 27 patients (81.8%). Chorioretinal scarring (p=0.014) and posterior uveitis (p=0.004) was significantly associated with ocular toxoplasmosispatients. Multi-locus genotyping showed genotype I. Ocular toxoplasmosis showed no significant correlation with gender, age, behaviours, occupation or education. CONCLUSION: Clinical manifestations, serological and molecular detection of Toxoplasma were highly correlated in the diagnosis of ocular toxoplasmosis. Genotype I was predominant in ocular toxoplasmosis in northwest Iran. A larger comparative study should be conducted to provide a broader view of the molecular epidemiology of T. gondii genotypes and its role in toxoplasmosis.
Authors: Saé Muñiz-Hernández; Angélica Luna-Nophal; Carmen T Gómez-De León; Lenin Domínguez-Ramírez; Olga A Patrón-Soberano; Karen E Nava-Castro; Pedro Ostoa-Saloma; Jorge Morales-Montor Journal: Microorganisms Date: 2021-03-02