Comparison of polymerase chain reaction-restriction fragment length polymorphism and assemblage-specific primers for characterization of in children.

BACKGROUND

is a diarrheagenic eukaryotic parasite that consists of at least eight morphologically identical but genetically distinct genotypes. Human giardiasis is caused mainly by A and B assemblages.

AIM AND OBJECTIVES

The study aimed to compare the performance of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and assemblage-specific primers in genotyping of .

MATERIALS AND METHODS

Stool samples of 315 children were microscopically screened for . Positive samples were genotyped using assemblage-specific primers and semi-nested PCR-RFLP techniques.

RESULTS

The prevalence of was 18.1%. The detected genotypes using and approaches were assemblage A (15.8% vs. 12.7%) and assemblage B (36.8% vs. 74.5%) as single infections and mixed assemblages A and B (47.4% vs. 12.7%). The two approaches showed a moderate agreement (kappa index = 0.413, < 0.001). PCR-RFLP of gene revealed that sub-assemblages BIII and BIV were equally detected (30.9% each). The remaining samples were equally divided between sub-assemblage AII, mixed BIII and BIV, and mixed AII and BIII (12.7% each). A significant association was detected between the retrieved sub-assemblages and the presence of symptoms.

CONCLUSIONS

Although both approaches confirmed the predominance of assemblage B, the use of assemblage-specific primers is more effective in elucidating the true picture of mixed assemblage infection.