Division of Parasitology, ICMR-National Institute of Cholera and Enteric Diseases, P-33 CIT Road, Scheme XM, Beliaghata, Kolkata 700010, West Bengal, India.
Department of Parasitology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan.
Parasitol Int. 2021 Aug;83:102370. doi: 10.1016/j.parint.2021.102370. Epub 2021 Apr 29.
Amoebiasis caused by protozoan parasite Entamoeba histolytica has diverse infection outcomes. The relationship between parasite genotypes and outcome of amoebic infection is still a paradox and needs to be explored. Genome information of infecting strains from endemic areas throughout the world is essential to explore this relation. Comparative genetics between E. histolytica populations from different disease outcomes have been studied to identify potential genetic markers having single nucleotide polymorphisms (SNPs) significantly associated with specific clinical outcome. Coding and non-coding regions have significantly different rates of polymorphism. Non-synonymous base substitutions were significantly more frequent than synonymous within coding loci. Both synonymous and non-synonymous SNPs within lysine- and glutamic acid rich protein 2 (kerp2) locus were significantly associated with disease outcomes. An incomplete linkage disequilibrium (LD) value with potential recombination events and significant population differentiation (F) value have also been identified at kerp2 locus within the study population. Presence of disease specific SNPs, potential recombination events, and significant F value at kerp2 locus indicate that kerp2 gene and its gene product are under constant selection pressure exerted by host on parasite and could also be a potential determinant of disease outcome of E. histolytica infection. Furthermore, E. histolytica isolated from asymptomatic carriers are phylogenetically closer to those causing liver abscess in human and exhibit potential inter-population recombination among them. Individuals with persistent asymptomatic E. histolytica infection may be under high risk of developing amoebic liver abscess formation in future and detailed investigation of asymptomatic individuals from endemic areas should be always required.
由原生动物寄生虫溶组织内阿米巴引起的阿米巴病有多种感染结果。寄生虫基因型与阿米巴感染结果之间的关系仍然存在矛盾，需要进一步探索。了解世界各地流行地区感染株的基因组信息对于探索这种关系至关重要。已经研究了来自不同疾病结果的溶组织内阿米巴群体之间的比较遗传学，以确定与特定临床结果显著相关的潜在遗传标记，这些标记具有单核苷酸多态性（SNP）。编码和非编码区域的多态性率有显著差异。编码基因座内的非同义碱基取代明显多于同义取代。赖氨酸和谷氨酸丰富蛋白 2（kerp2）基因座内的同义和非同义 SNP 都与疾病结果显著相关。在研究人群中，kerp2 基因座也存在不完全连锁不平衡（LD）值、潜在重组事件和显著的种群分化（F）值。在 kerp2 基因座上存在疾病特异性 SNP、潜在的重组事件和显著的 F 值，表明 kerp2 基因及其基因产物受到宿主对寄生虫的持续选择压力的影响，也可能是溶组织内阿米巴感染疾病结果的潜在决定因素。此外，从无症状携带者中分离出的溶组织内阿米巴在系统发育上更接近引起人类肝脓肿的那些菌株，并且它们之间存在潜在的种群间重组。持续无症状携带溶组织内阿米巴的个体未来可能有很高的风险发展为肝脓肿形成，因此应该始终对流行地区的无症状个体进行详细调查。
