title: Circumsporozoite protein gene diversity among temperate and tropical Plasmodium vivax isolates from Iran.
abstract: To date, there is no information on the genetic diversity of the circumsporozoite protein (CSP), a leading vaccine candidate, in Plasmodium vivax populations circulating in Iran. The gene for this protein, Pvcsp, was amplified from 374 P. vivax isolates collected in the temperate northern, and in the tropical southern endemic areas. PCR-RFLP analysis of the repeated central region revealed that the parasites collected in the northern area were almost exclusively of the VK210 type. Parasites collected in the south-eastern areas were of both VK210 and VK247 types. We detected VK210 parasite in 70.5% of the samples, VK247 parasites in 17.5% and mixed type infections in 12% of the isolates. Sequence analysis of 137 isolates obtained from both areas identified a total of 25 distinct genotypes. The degree of genetic diversity was generally higher for the tropical (21 genotypes) than the temperate (7 genotypes) P. vivax populations, a difference possibly reflecting the high cross-border exchanges between Afghanistan and Pakistan and southern Iran. Interestingly, all but two VK210 type isolates sequenced harboured a 36-bp post-repeat insert previously only observed in North Korea and China. This large-scale survey of parasite diversity in the Eastern Mediterranean Region provides a set of baseline data suitable for future molecular epidemiological studies of P. vivax.
authors.affiliation: Malaria Research Group, Biotechnology Department, Pasteur Institute of Iran, Tehran, Iran. zakeris@yahoo.com
authors.forename: Sedigheh
authors.initials: S
authors.lastname: Zakeri
authors.forename: Akram
authors.initials: A
authors.lastname: Abouie Mehrizi
authors.forename: Navid Diparast
authors.initials: ND
authors.lastname: Djadid
authors.forename: Georges
authors.initials: G
authors.lastname: Snounou
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D000595:Amino Acid Sequence / Q000235:genetics; D000818:Animals; D002648:Child; D002675:Child, Preschool; D019353:Endemic Diseases; D005784:Gene Amplification / Q000235:genetics; D005838:Genotype; D006801:Humans; D007223:Infant; D007492:Iran / Q000453:epidemiology / Q000208:ethnology; D016780:Malaria, Vivax / Q000453:epidemiology / Q000208:ethnology / Q000235:genetics*; D008875:Middle Aged; D010802:Phylogeny; D010966:Plasmodium vivax / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length; D011159:Population Surveillance / Q000379:methods; D015800:Protozoan Proteins / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D016415:Sequence Alignment; D014329:Tropical Climate
chemical_list: D015800:Protozoan Proteins; C041595:circumsporozoite protein, Protozoan