Genetic polymorphisms of Plasmodium falciparum isolates from Melka-Werer, North East Ethiopia based on the merozoite surface protein-2 (msp-2) gene as a molecular marker

Abstract

Background The characterization of parasite populations circulating in malaria endemic areas is necessary to evaluate the success of ongoing interventions and malaria control strategies. This study was designed to investigate the genetic diversity of Plasmodium falciparum isolates from the semi-arid area in North East Ethiopia, using the highly polymorphic merozoite surface protein-2 (msp2) gene as a molecular marker. Methods Dried blood spot isolates were collected from patients with P. falciparum infection between September 2014 and January 2015 from Melka-Werer, North East Ethiopia. Parasite DNA was extracted and genotyped using allele-specific nested polymerase chain reactions for msp2. Results 52 isolates were collected with msp2 identified in 41 (78.8%) isolates. Allele typing of the msp2 gene detected the 3D7/IC allelic family in 54% and FC27 allelic family in 46%. A total of 14 different msp2 genotypes were detected including 6 belonging to the 3D7/IC family and 8 to the FC27 family. Forty percent of isolates had multiple genotypes and the overall mean multiplicity of infections (MOI) was 1.2 (95%CI 0.96–1.42). The heterozygosity index was 0.50 for the msp2 locus. There was no difference in MOI between age groups. A negative correlation between parasite density and multiplicity of infection was found (p = 0.02). Conclusion Plasmodium falciparum isolates from the semi-arid area of North East Ethiopia are mainly monoclonal with low MOI and limited genetic diversity in the study population.

Polymorphism of Block3 Region of Merozoite Surface Protein-2 Gene and Multiplicity of Infection in Plasmodium Falciparum in Urban and Rural Settings of Adama and Its Surroundings, Oromia, Ethiopia.

“…Although the number of genotypes might have be underestimated due to the limitation of the techniques. Fragment size polymorphism described in this study is nearly comparable with the previous report from Republic of Congo [28], Nigeria [29], Sudan [17], and northeastern Ethiopia [30]. Other reports from Congo Brazzaville [31], north western Ethiopia [32] shown the predominance of IC/3D7 allelic family.…”

“…This nding is lower than the previous report from southwestern Ethiopia [33] northwesten Ethiopia [32], Sudan [17], Cameroon [34], and Nigeria [35]. And somewhat higher than the previous report from north eastern Ethiopia [30], and Ghana [36]. The variation in multi-clonal infection and multiplicity of infection could be due to the overall prevalence of infection in the population and the age of the individual [37].…”

Plasmodium falciparum Clinical Isolates Reveal Analogous Circulation of 3D7 and FC27 Allelic Variants and Multiplicity of Infection in Urban and Rural Settings: The Case of Adama and Its Surroundings, Oromia, Ethiopia

“…Amplification and gel-electrophoresis of msp-2 alleles in the study revealed 113 and 102 fragments for 3D7 and FC27 genotypes, respectively. Thus, mean MOI could be estimated by dividing the total number of gel fragments detected in the msp-2 gene by the total number of positive samples in the same marker [ 28 , 29 ], which indicates the average number of genotypes per infected subject.…”

Evidence of a Recent Bottleneck in Plasmodium falciparum Populations on the Honduran–Nicaraguan Border

“…has been related to the ability of parasites to adapt adequately to their hosts through the selection of advantageous traits, such as antigenic variability that allows them to evade the immune response, as well as the emergence of mutations responsible for resistance to antimalarials [3][4][5][6][7]. Genetically diverse populations of Plasmodium are common in regions with high transmission patterns, such as sub-Saharan Africa and some Southeast Asian countries [8][9][10][11][12], but as the incidence of malaria declines, the parasite's genetic diversity is expected to decline as well [13,14]. Central America is considered a region of moderate to low malaria transmission, and studies on the genetic diversity of Plasmodium spp.…”