ABSTRACT
Plasmodium vivax is responsible for approximately 80 million malaria cases in the world. Apical membrane antigen1 [AMA-1] is a type I integral membrane protein present in all Plasmodium species. AMA-1 interferes in critical steps of invasion of human hepatocytes by sporozoites and red blood cells by merozoites and is one of the most immunodominant antigens for eliciting a protective immune response in human. It is considered as a promising antigen for inclusion in a vaccine against P. vivax. Since more knowledge is needed to lighten the scope of such antigen we compared genetic variation in P. vivax AMA-1from an Iranian isolate with those reported from some of the other malarious countries so far. P. vivax genomic DNA was extracted from the whole blood of an Iranian patient with patent P. vivax infection. The nucleotide sequence for 446 amino acid [AA] residues [42-488 of PvAMA-1] was amplified by PCR and cloned in pUC19 vector for sequencing. Sequence analysis of the antigen showed a high degree of identity [99%] with strong homology to the PvAMA-1 gene of P. vivax S3 and SKO814 isolates from India and Korea [Asian isolates] respectively, and 96% similarity with P. vivax Sal-1 AMA-1 gene from El Salvador. We cloned and characterized three domains of PvAMA-1 gene from an Iranian patient. Predicted protein sequence of this gene showed some discrepancies in corresponding protein in comparing with similar genes reported from other malarious countries
ABSTRACT
Vahlkampfiids contains wide variety of genuses with some known as human pathogens such as Naegleria, Vahlkampfia and non pathogens such as Willaertia. Since there was no evidence of presence of Vahlkampfiids in different sources in Iran, we have analyzed soil samples to clarify the presence of these amebas. Seven soil samples collected in Tehran were analyzed to clarify the presence of Vahlkampfiids in soil sources, using microscopic examination of non nutrient agar cultures and specific Vahlkampfiids primer pair. Vahlkampfiids were detected in 2 out of 7 soil samples by direct examination of cultures. Sequence analysis confirmed that Willaertia magna [W. magna] was present in 2 samples. Additionally, Thecamoeba were detected in all of soil samples. To the best of our knowledge, this is the first report of existing W. magna and Thecamoeba in Iran. Over all, more research should be implicated in Iran for identification of Vahlkampfiids within different environmental sources as well as their pathogenic capability relevant for human beings