Genetic polymorphism of <I>Plasmodium falciparum</I> populations has been studied in two localities in Sudan, Khartoum the capital and Asar village in the eastern region. The frequencies of alleles of three antigens denoted MSP-1, and MSP-2 and Exp-1, three enzymes and nine polymorphic proteins detected by 2D-PAGE were investigated. Parasites from both areas were found to be very diverse, and frequently patients were infected with more than one genotype. Allelic polymorphism was slightly lower in Asar than in Khartoum. <I>In vitro</I> responses to chloroquine, pyrimethamine and mefloquine were assessed among the parasites of Asar in 1989 and 1990. The parasites were found to have diverse responses to chloroquine and pyrimethamine in both years. The prevalence of parasites sensitive and resistant to pyrimethamine varied considerably between 1989 and 1990, but the responses to chloroquine remained more or less stable. Characterisation of R1-type chloroquine resistant parasites for antigen genes proved that they were genuine recrudescent resistant parasites, and not derived from new infections. The antigens, 2D-PAGE proteins and enzymes, were again monitored in 1990. In addition, alleles of MSP-1 and MSP-2 were characterised by PCR-amplification and allele-specific DNA probes in 1990 and 1991. Some changes in the frequencies of certain alleles were noted from one year to another. The MSP-1 & MSP-2 alleles identified by the PCR/DNA probes and the frequency of multiclonal infection in Asar in 1991 were compared to those of parasites collected in the same year in a village of similar size, Michenga, in Tanzania.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:641179 |
| Date | January 1994 |
| Creators | Babiker, Hamza Ali |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/10687 |
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