Genetic diversity of Plasmodium falciparum in Grande Comore Island

Abstract

Background: Despite several control interventions resulting in a considerable decrease in malaria prevalence in the Union of the Comoros, the disease remains a public health problem with high transmission in Grande Comore compared to neighbouring islands. In this country, only a few studies investigating the genetic diversity of Plasmodium falciparum have been performed so far. For this reason, this study aims to examine the genetic diversity of P. falciparum by studying samples collected in Grande Comore in 2012 and 2013, using merozoite surface protein 1 (msp1), merozoite surface protein 2 (msp2) and single nucleotide polymorphism (SNP) genetic markers. Methods: A total of 162 positive rapid diagnostic test (RDT) samples from Grande Comore were used to extract parasite DNA. Allelic families K1, Mad20 and RO33 of the msp1 gene as well as allelic families IC3D7 and FC37 of the msp2 gene were determined by using nested PCR. Additionally, 50 out of 151 samples were genotyped to study 24 SNPs by using high resolution melting (HRM). Results: Two allelic families were predominant, the K1 family of msp1 gene (55%) and the FC27 family of msp2 gene (47.4%). Among 50 samples genotyped for 24 SNPs, 42 (84%) yielded interpretable results. Out of these isolates, 36 (85%) were genetically unique and 6 (15%) grouped into two clusters. The genetic diversity of P. falciparum calculated from msp1 and msp2 genes and SNPs was 0.82 and 0.61, respectively. Conclusion: In summary, a large genetic diversity of P. falciparum was observed in Grande Comore. This may favour persistence of malaria and might be one of the reasons for the high malaria transmission compared to neighbouring islands. Further surveillance of P. falciparum isolates, mainly through environmental management and vector control, is warranted until complete elimination is attained.

Low Allelic Variation of Plasmodium falciparum msp-1 and msp-2 among Gold Miners in Central Kalimantan Province, Indonesia

“…Interestingly, the RO33 allelic family was not found in Central Kalimantan Province. This result is different with that found in Pahang, Malaysia, where RO33 allelic family was predominant as monomorphic ( 38 ), in contrast with that found in Grande Comoro Island where RO33 allelic family were poorly represented (2.4–4.0%) ( 39 ), while in Myanmar-China border was higher (12.56%) ( 17 ). In Gabon, when the DNA was isolated from RDTs showed that K1 (93.9%) was found higher than MAD20 (73.3%) ( 40 ).…”

Genetic Diversity of Polymorphic Marker Merozoite Surface Protein 1 (Msp-1) and 2 (Msp-2) Genes of Plasmodium falciparum Isolates From Malaria Endemic Region of Pakistan

“…Furthermore, of 192 positive samples for P. falciparum , less than half showed an amplicon for msp-1 (n = 97) or msp-2 (n = 95). In previous studies, relatively higher numbers of amplicons were observed for msp-1 or msp-2 ( Somé et al, 2018 ; Mohammed et al, 2019 ; Eltayeb et al, 2020 ; Papa Mze et al, 2020 ). The nonspecific binding during P. falciparum identification by PCR may justify the smaller number of amplicons for msp-1 and msp-2 in the current study.…”