Analysis of sulphadoxine-pyrimethamine resistance-associated mutations in Plasmodium falciparum isolates obtained from asymptomatic pregnant women in Ogun State, Southwest Nigeria.

Intermittent preventive treatment in pregnancy with sulphadoxine-pyrimethamine (IPTp-SP) is one of the main strategies for protecting pregnant women, fetus, and their new-born against adverse effects of P. falciparum infection. The development of the drug resistance linked to mutations in P. falciparum dihydrofolate reductase gene (pfdhfr) and P. falciparum dihydropteroate synthase gene (pfdhps), is currently threatening the IPTp-SP approach. This study determined the prevalence of pfdhfr and pfdhps mutations in isolates obtained from pregnant women with asymptomatic P. falciparum infection in Nigerian. Additionally, P. falciparum genetic diversity and multiplicity of infection (MOI) was assessed by genotyping the P. falciparum merozoite surface Protein 1 and 2 (pfmsp-1 and pfmsp-2) genes. The pfdhfr and pfdhps were genotyped by direct sequencing, and the pfmsp-1 and pfmsp-2 fragment analysis by polymerase chain reaction was used to determine P. falciparum genetic diversity. Of the 406 pregnant women recruited, 123 had P. falciparum infection by PCR, and of these, 52 were successfully genotyped for pfdhfr and 42 for pfdhps genes. The pfdhfr triple-mutant parasites (N51I, C59R, and S108N) or the IRN haplotype were predominant (98%), whereas pfdhfr mutations C50R and I164L did not occur. For pfdhps gene, the prevalence of A437G, A581G, A436A, and A613S mutations were 98, 71, 55, and 36%, respectively. Nineteen (44%) isolates with quintuple mutations (CIRNI- SGKGA) had the highest combined pfdhfr-pfdhps haplotype. Isolates with sextuple mutants; CIRNI- AGKAS and CIRNI- AGKGA had a prevalence of 29 and 14%, respectively. High genetic diversity (7 pfmsp-1 alleles and 10 pfmsp-2 alleles) and monoclonal infection rate (76%) was observed. This study demonstrated a continuous high prevalence of pfdhfr mutation and an increase in pfdhps mutations associated with SP-resistance in southwest Nigeria. Continuous surveillance of IPTp-SP effectiveness and consideration of alternative IPTp strategies is recommended.

HLA Class II Allele, Haplotype, and Genotype Associations with Type 1 Diabetes in Benin: A Pilot Study.

BACKGROUND: Several studies have reported the implication of HLA-DR/DQ loci in the susceptibility to type 1 diabetes (T1D). Since no such study has yet been performed in Benin, this pilot one aimed at assessing HLA class II allele, haplotype, and genotype associations with T1D. MATERIAL AND METHODS: Class II HLA genotyping was performed in 51 patients with T1D and 51 healthy unrelated controls by means of the PCR-SSP method. The diagnosis of T1D was set up according to American Diabetes Association criteria. Odds ratio (OR) and its 95% confidence interval (95% CI) were calculated to assess the associations between T1D and HLA alleles, haplotypes, and genotypes. RESULTS: Participants were aged 1-24 years. T1D was significantly associated with DR3, DQA1∗05:01, DQB1∗02:01, and DR3-DR4. No significant associations were observed with DR4, DQB1∗03:02, and DQB1∗06:02. CONCLUSION: Certain HLA class II alleles, haplotypes, and genotypes were related to T1D and may be used as genetic susceptibility markers to T1D in Benin.