Genotyping Of Toxoplasma Gondii Strains In Patients With Hepatitis B And C Demonstrated A Predominant Distribution Of The Type II Genotype

Abstract

Background: Toxoplasma gondii is a globally prevalent intracellular parasite causing toxoplasmosis, with serious health and economic impacts. It infects various warm-blooded hosts and can affect multiple organs, including the liver. Its pathogenicity is linked to genetic diversity, primarily among genotypes I, II, and III. The GRA6 gene, due to its high polymorphism, is a reliable molecular marker for distinguishing these genotypes and assessing strain variation more effectively than the commonly used B1 gene.

Methods: A total of 100 samples from chronic hepatitis patients were screened for Toxoplasma gondii using ELISA; 62 were positive. B1 gene PCR confirmed infection in selected samples, and 10 B1-positive samples (5 HBV, 5 HCV) were tested for the GRA6 gene using nested PCR. DNA was extracted with a commercial kit, and amplification used specific primers. Genotyping was performed via PCR-RFLP targeting the GRA6 gene, using the MseI enzyme to distinguish T. gondii strains based on fragment sizes.

Results: This study used nested-PCR and RFLP targeting the GRA6 gene to genotype Toxoplasma gondii in hepatitis B and C patients in Thi-Qar, Iraq. Of 100 ELISA-screened samples, 20 tested positive for the B1 gene by PCR, and 5 from each group (HBV, HCV) were GRA6-positive. RFLP analysis using MseI differentiated genotypes I, II, and III. Among chronic liver diseases patients, genotype II was dominated.

Conclusions: Our recent study genotyped Toxoplasma gondii in HBV and HCV patients using nested-PCR and RFLP targeting the GRA6 gene. Genotypes II predominated in Hepatitis patients. These findings align with regional data showing genotype II’s prevalence in immunocompromised individuals, highlighting the importance of molecular genotyping for understanding strain distribution and its potential impact on disease outcomes.