Elhadad Heba, Abdo Sarah, Salem Aziza I, Mohamed Mostafa A, El-Taweel Hend A, El-Abd Eman A
Department of Parasitology, Medical Research Institute, Alexandria University, Alexandria, Egypt.
Department of Parasitology, Faculty of Medicine, Medical Research Institute, Alexandria University, Alexandria, Egypt.
Trop Parasitol. 2022 Jan-Jun;12(1):41-47. doi: 10.4103/tp.tp_28_21. Epub 2022 Jun 26.
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.
The study aimed to compare the performance of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and assemblage-specific primers in genotyping of .
Stool samples of 315 children were microscopically screened for . Positive samples were genotyped using assemblage-specific primers and semi-nested PCR-RFLP techniques.
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.
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.
贾第虫是一种致腹泻的真核寄生虫，至少由八种形态相同但基因不同的基因型组成。人类贾第虫病主要由A和B基因型引起。
本研究旨在比较聚合酶链反应-限制性片段长度多态性（PCR-RFLP）和基因型特异性引物在贾第虫基因分型中的性能。
对315名儿童的粪便样本进行显微镜检查以筛查贾第虫。对阳性样本使用基因型特异性引物和半巢式PCR-RFLP技术进行基因分型。
贾第虫的患病率为18.1%。使用两种方法检测到的基因型，单一感染时为A基因型（分别为15.8%和12.7%）和B基因型（分别为36.8%和74.5%），A和B基因型混合感染时为（分别为47.4%和12.7%）。两种方法显示出中等一致性（kappa指数=0.413，P<0.001）。贾第虫基因的PCR-RFLP显示，BIII和BIV亚基因型的检测率相同（均为30.9%）。其余样本在AII亚基因型、BIII和BIV混合亚基因型以及AII和BIII混合亚基因型之间平均分配（各占12.7%）。在检测到的亚基因型与症状之间发现了显著关联。
虽然两种方法都证实了B基因型的优势，但使用基因型特异性引物在阐明混合基因型感染的真实情况方面更有效。
