Molecular epidemiology of malaria in Cameroon. XI. Geographic distribution of Plasmodium falciparum isolates with dihydrofolate reductase gene mutations in southern and central Cameroon.
The DNA sequence of the dihydrofolate reductase (dhfr) gene, a molecular marker for pyrimethamine resistance, was determined for 178 field isolates of Plasmodium falciparum collected along the east-west axis in southern Cameroon. The proportion of isolates having the wild-type dhfr allele varied from 48.1% in the east (city of Bertoua) to 11.3-15.7% in central provinces (Yaounde and Eseka) and 0% in the littoral region (port city of Douala). Isolates with a single Asn-108 mutation or double mutations (Ile-51 or Arg-59 and Asn-108) constituted approximately 10% of the samples. Isolates with triple mutations (Ile-51, Arg-59, and Asn-108) were present in an equal proportion (48.1%) as the wild-type isolates in the east (Bertoua), while triple mutations predominated in Yaounde (62.3%), Eseka (62.7%), and Douala (78.9%). The distribution of triple dhfr mutations along the east-west axis in southern Cameroon suggests the presence of a decreasing gradient from the west coastal region to the central region and then to the east towards the interior of the country.
Basco
Leonardo K
LK
Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC) and Unité de Recherche Paludologie Afro-tropicale, Institut de Recherche pour le Développement (IRD), Yaounde, Cameroon.
Ndounga
Mathieu
M
Tejiokem
Mathurin
M
Ngane
Vincent Foumane
VF
Youmba
Jean-Christian
JC
Ringwald
Pascal
P
Soula
Georges
G
D000483:Alleles; D000818:Animals; D001483:Base Sequence; D002163:Cameroon / Q000453:epidemiology; D002675:Child, Preschool; D017931:DNA Primers; D005787:Gene Frequency; D006801:Humans; D007223:Infant; D016778:Malaria, Falciparum / Q000453:epidemiology* / Q000235:genetics; D017720:Molecular Epidemiology; D009154:Mutation; D010963:Plasmodium falciparum / Q000201:enzymology / Q000235:genetics*; D016133:Polymerase Chain Reaction; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics*
D017931:DNA Primers; D013762:Tetrahydrofolate Dehydrogenase