DNA recovery from archived RDTs for genetic characterization of Plasmodium falciparum in a routine setting in Lambaréné, Gabon.
Malar J
; 18(1): 336, 2019 Oct 02.
Article
em En
| MEDLINE
| ID: mdl-31578142
ABSTRACT
BACKGROUND:
Rapid diagnostic tests (RDTs) have been described as a source of genetic material to analyse malaria parasites in proof-of-concept studies. The increasing use of RDTs (e.g., in focal or mass screening and treatment campaigns) makes this approach particularly attractive for large-scale investigations of parasite populations. In this study, the complexity of Plasmodium falciparum infections, parasite load and chloroquine resistance transporter gene mutations were investigated in DNA samples extracted from positive RDTs, obtained in a routine setting and archived at ambient temperature.METHODS:
A total of 669 archived RDTs collected from malaria cases in urban, semi-urban and rural areas of central Gabon were used for P. falciparum DNA extraction. Performance of RDTs as a source of DNA for PCR was determined using (i) amplification of a single copy merozoite surface protein 1 (msp1) gene followed by highly sensitive and automated capillary electrophoresis; (ii) genotyping of the pfcrt gene locus 72-76 using haplotype-specific-probe-based real-time PCR to characterize chloroquine resistance; and, (iii) real-time PCR targeting 18S genes to detect and quantify Plasmodium parasites.RESULTS:
Out of the 669 archived RDTs, amplification of P. falciparum nucleic materials had a success rate of 97% for 18S real-time PCR, and 88% for the msp1 gene. The multiplicity of infections (MOI) of the whole population was 2.6 (95% CI 2.5-2.8). The highest number of alleles detected in one infection was 11. The MOI decreased with increasing age (ß = - 0.0046, p = 0.02) and residence in Lambaréné was associated with smaller MOIs (p < 0.001). The overall prevalence of mutations associated with chloroquine resistance was 78.5% and was not associated with age. In Lambaréné, prevalence of chloroquine resistance was lower compared to rural Moyen-Ogooué (ß = - 0.809, p-value = 0.011).CONCLUSION:
RDT is a reliable source of DNA for P. falciparum detection and genotyping assays. Furthermore, the increasing use of RDTs allows them to be an alternative source of DNA for large-scale genetic epidemiological studies. Parasite populations in the study area are highly diverse and prevalence of chloroquine-resistant P. falciparum remains high, especially in rural areas.Palavras-chave
Texto completo:
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Bases de dados:
MEDLINE
Assunto principal:
Plasmodium falciparum
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Proteínas de Protozoários
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DNA de Protozoário
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Malária Falciparum
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Bancos de Espécimes Biológicos
Tipo de estudo:
Diagnostic_studies
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Observational_studies
/
Risk_factors_studies
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Screening_studies
Limite:
Adolescent
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Adult
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Child
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Child, preschool
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Female
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Humans
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Male
País/Região como assunto:
Africa
Idioma:
En
Revista:
Malar J
Assunto da revista:
MEDICINA TROPICAL
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Alemanha