Optimization and validation of multi-coloured capillary electrophoresis for genotyping of Plasmodium falciparum merozoite surface proteins (msp1 and 2)

Liljander, Anne; Wiklund, Lisa; Falk, Nicole; Kweku, Margaret; Mårtensson, Andreas; Felger, Ingrid; Färnert, Anna

doi:10.1186/1475-2875-8-78

Cited by 84 publications

(83 citation statements)

References 23 publications

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“…This confirms a high degree of sensitivity of the typing method to detect multiple infections in PNG. 36 Similar proportions of 3D7 and FC27-type alleles were present in each population (Supplemental Table S1, Figure 2).…”

Section: Resultsmentioning

confidence: 70%

“…The detection of 83 distinct msp2 alleles throughout the study area confirms high levels of sensitivity of the methodology to detect multiple clones. 36 The molecular data also provided the opportunity to measure the genetic diversity in villages with a wide range of infection prevalences, particularly those within the East Sepik region during the dry season and post-LLIN distribution. Figure 3.…”

Section: Discussionmentioning

confidence: 99%

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High Levels of Genetic Diversity of Plasmodium falciparum Populations in Papua New Guinea despite Variable Infection Prevalence

Barry

Schultz

Senn

et al. 2013

The American Society of Tropical Medicine and Hygiene

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Abstract. High levels of genetic diversity in Plasmodium falciparum populations are an obstacle to malaria control. Here, we investigate the relationship between local variation in malaria epidemiology and parasite genetic diversity in Papua New Guinea (PNG). Cross-sectional malaria surveys were performed in 14 villages spanning four distinct malariaendemic areas on the north coast, including one area that was sampled during the dry season. High-resolution msp2 genotyping of 2,147 blood samples identified 761 P. falciparum infections containing a total of 1,392 clones whose genotypes were used to measure genetic diversity. Considerable variability in infection prevalence and mean multiplicity of infection was observed at all of the study sites, with the area sampled during the dry season showing particularly striking local variability. Genetic diversity was strongly associated with multiplicity of infection but not with infection prevalence. In highly endemic areas, differences in infection prevalence may not translate into a decrease in parasite population diversity.

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Section: Resultsmentioning

confidence: 70%

Section: Discussionmentioning

confidence: 99%

High Levels of Genetic Diversity of Plasmodium falciparum Populations in Papua New Guinea despite Variable Infection Prevalence

Barry

Schultz

Senn

et al. 2013

The American Society of Tropical Medicine and Hygiene

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show abstract

“…Electropherograms were viewed using Peak Scanner (version 1.0), and all discrete peaks 500 florescent units were considered to be distinct allelic types. 29 Case definitions. Subpatent malaria infections were infections in individuals who tested positive for malaria by nPCR but negative for malaria by RDT; patent infections were defined as infections in individuals who were positive by both nPCR and RDT.…”

Section: Methodsmentioning

confidence: 99%

High Levels of Asymptomatic and Subpatent Plasmodium falciparum Parasite Carriage at Health Facilities in an Area of Heterogeneous Malaria Transmission Intensity in the Kenyan Highlands

Stresman¹,

Stevenson²,

Ngwu³

et al. 2014

The American Society of Tropical Medicine and Hygiene

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Abstract. In endemic settings, health facility surveys provide a convenient approach to estimating malaria transmission intensity. Typically, testing for malaria at facilities is performed on symptomatic attendees, but asymptomatic infections comprise a considerable proportion of the parasite reservoir. We sampled individuals attending five health facilities in the western Kenyan highlands. Malaria prevalence by rapid diagnostic test (RDT) was 8.6-32.9% in the health facilities. Of all polymerase chain reaction-positive participants, 46.4% (95% confidence interval [95% CI] = 42.6-50.2%) of participants had infections that were RDT-negative and asymptomatic, and 55.9% of those infections consisted of multiple parasite clones as assessed by merozoite surface protein-2 genotyping. Subpatent infections were more common in individuals reporting the use of non-artemisinin-based antimalarials in the 2 weeks preceding the survey (odds ratio = 2.49, 95% CI = 1.04-5.92) compared with individuals not reporting previous use of antimalarials. We observed a large and genetically complex pool of subpatent parasitemia in the Kenya highlands that must be considered in malaria interventions.

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“…How much technical reasons contribute to imperfect detectability of individual clones has not been investigated systematically for the three prime P. falciparum genotyping markers msp1 , msp2 , and glurp , but circumstantial observations of clone competition during PCR can be found in the literature (15, 16). …”

Section: Introductionmentioning

confidence: 99%

Critical Evaluation of Molecular Monitoring in Malaria Drug Efficacy Trials and Pitfalls of Length-Polymorphic Markers

Messerli

Hofmann

Beck

et al. 2017

Antimicrob Agents Chemother

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Estimation of drug efficacy in antimalarial drug trials requires parasite genotyping to distinguish new infections from treatment failures. When using length-polymorphic molecular markers, preferential amplification of short fragments can compromise detection of coinfections, potentially leading to misclassification of treatment outcome. We quantified minority clone detectability and competition among msp1, msp2, and glurp amplicons using mixtures of Plasmodium falciparum strains and investigated the impact of template competition on genotyping outcomes in 44 paired field samples. Substantial amplification bias was detected for all three markers, with shorter fragments outperforming larger fragments. The strongest template competition was observed for the marker glurp. Detection of glurp fragments in multiclonal infections was severely compromised. Eight of 44 sample pairs were identified as new infections by all three markers. Ten pairs were defined as new infections based on one marker alone, seven of which were defined by the questionable marker glurp. The impact of size-dependent template competition on genotyping outcomes therefore calls for necessary amendments to the current WHO recommendations for PCR correction of malaria drug trial endpoints. Accuracy of genotyping outcomes could be improved by separate amplification reactions per allelic family and basing results on markers msp1 and msp2 first, with glurp only used to resolve discordant results.

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Optimization and validation of multi-coloured capillary electrophoresis for genotyping of Plasmodium falciparum merozoite surface proteins (msp1 and 2)

Cited by 84 publications

References 23 publications

High Levels of Genetic Diversity of Plasmodium falciparum Populations in Papua New Guinea despite Variable Infection Prevalence

High Levels of Genetic Diversity of Plasmodium falciparum Populations in Papua New Guinea despite Variable Infection Prevalence

High Levels of Asymptomatic and Subpatent Plasmodium falciparum Parasite Carriage at Health Facilities in an Area of Heterogeneous Malaria Transmission Intensity in the Kenyan Highlands

Critical Evaluation of Molecular Monitoring in Malaria Drug Efficacy Trials and Pitfalls of Length-Polymorphic Markers

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