Nonradioactive heteroduplex tracking assay for the detection of minority-variant chloroquine-resistant Plasmodium falciparum in Madagascar
Abstract Background Strains of Plasmodium falciparum genetically resistant to chloroquine (CQ) due to the presence of pfcrt 76T appear to have been recently introduced to the island of Madagascar. The prevalence of such resistant genotypes is reported to be low (< 3%) when evaluated by convention...
Published in: | Malaria Journal |
---|---|
Main Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
BMC
2009
|
Subjects: | |
Online Access: | https://doi.org/10.1186/1475-2875-8-47 https://doaj.org/article/33bc0f27b93c4b73adaca334c30224eb |
id |
ftdoajarticles:oai:doaj.org/article:33bc0f27b93c4b73adaca334c30224eb |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:33bc0f27b93c4b73adaca334c30224eb 2023-05-15T15:14:20+02:00 Nonradioactive heteroduplex tracking assay for the detection of minority-variant chloroquine-resistant Plasmodium falciparum in Madagascar Mwapasa Victor Ariey Frédéric Ramarosandratana Benjamin Randrianarivelojosia Milijaona Juliano Jonathan J Meshnick Steven R 2009-03-01T00:00:00Z https://doi.org/10.1186/1475-2875-8-47 https://doaj.org/article/33bc0f27b93c4b73adaca334c30224eb EN eng BMC http://www.malariajournal.com/content/8/1/47 https://doaj.org/toc/1475-2875 doi:10.1186/1475-2875-8-47 1475-2875 https://doaj.org/article/33bc0f27b93c4b73adaca334c30224eb Malaria Journal, Vol 8, Iss 1, p 47 (2009) Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 article 2009 ftdoajarticles https://doi.org/10.1186/1475-2875-8-47 2022-12-31T01:45:20Z Abstract Background Strains of Plasmodium falciparum genetically resistant to chloroquine (CQ) due to the presence of pfcrt 76T appear to have been recently introduced to the island of Madagascar. The prevalence of such resistant genotypes is reported to be low (< 3%) when evaluated by conventional PCR. However, these methods are insensitive to low levels of mutant parasites present in patients with polyclonal infections. Thus, the current estimates may be an under representation of the prevalence of the CQ-resistant P. falciparum isolates on the island. Previously, minority variant chloroquine resistant parasites were described in Malawian patients using an isotopic heteroduplex tracking assay (HTA), which can detect pfcrt 76T-bearing P. falciparum minority variants in individual patients that were undetectable by conventional PCR. However, as this assay required a radiolabeled probe, it could not be used in many resource-limited settings. Methods This study describes a digoxigenin (DIG)-labeled chemiluminescent heteroduplex tracking assay (DIG-HTA) to detect pfcrt 76T-bearing minority variant P. falciparum . This assay was compared to restriction fragment length polymorphism (RFLP) analysis and to the isotopic HTA for detection of genetically CQ-resistant parasites in clinical samples. Results Thirty one clinical P. falciparum isolates (15 primary isolates and 16 recurrent isolates) from 17 Malagasy children treated with CQ for uncomplicated malaria were genotyped for the pfcrt K76T mutation. Two (11.7%) of 17 patients harboured genetically CQ-resistant P. falciparum strains after therapy as detected by HTA. RFLP analysis failed to detect any pfcrt K76T-bearing isolates. Conclusion These findings indicate that genetically CQ-resistant P. falciparum are more common than previously thought in Madagascar even though the fitness of the minority variant pfcrt 76T parasites remains unclear. In addition, HTAs for malaria drug resistance alleles are promising tools for the surveillance of anti-malarial resistance. ... Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic Malaria Journal 8 1 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 |
spellingShingle |
Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 Mwapasa Victor Ariey Frédéric Ramarosandratana Benjamin Randrianarivelojosia Milijaona Juliano Jonathan J Meshnick Steven R Nonradioactive heteroduplex tracking assay for the detection of minority-variant chloroquine-resistant Plasmodium falciparum in Madagascar |
topic_facet |
Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 |
description |
Abstract Background Strains of Plasmodium falciparum genetically resistant to chloroquine (CQ) due to the presence of pfcrt 76T appear to have been recently introduced to the island of Madagascar. The prevalence of such resistant genotypes is reported to be low (< 3%) when evaluated by conventional PCR. However, these methods are insensitive to low levels of mutant parasites present in patients with polyclonal infections. Thus, the current estimates may be an under representation of the prevalence of the CQ-resistant P. falciparum isolates on the island. Previously, minority variant chloroquine resistant parasites were described in Malawian patients using an isotopic heteroduplex tracking assay (HTA), which can detect pfcrt 76T-bearing P. falciparum minority variants in individual patients that were undetectable by conventional PCR. However, as this assay required a radiolabeled probe, it could not be used in many resource-limited settings. Methods This study describes a digoxigenin (DIG)-labeled chemiluminescent heteroduplex tracking assay (DIG-HTA) to detect pfcrt 76T-bearing minority variant P. falciparum . This assay was compared to restriction fragment length polymorphism (RFLP) analysis and to the isotopic HTA for detection of genetically CQ-resistant parasites in clinical samples. Results Thirty one clinical P. falciparum isolates (15 primary isolates and 16 recurrent isolates) from 17 Malagasy children treated with CQ for uncomplicated malaria were genotyped for the pfcrt K76T mutation. Two (11.7%) of 17 patients harboured genetically CQ-resistant P. falciparum strains after therapy as detected by HTA. RFLP analysis failed to detect any pfcrt K76T-bearing isolates. Conclusion These findings indicate that genetically CQ-resistant P. falciparum are more common than previously thought in Madagascar even though the fitness of the minority variant pfcrt 76T parasites remains unclear. In addition, HTAs for malaria drug resistance alleles are promising tools for the surveillance of anti-malarial resistance. ... |
format |
Article in Journal/Newspaper |
author |
Mwapasa Victor Ariey Frédéric Ramarosandratana Benjamin Randrianarivelojosia Milijaona Juliano Jonathan J Meshnick Steven R |
author_facet |
Mwapasa Victor Ariey Frédéric Ramarosandratana Benjamin Randrianarivelojosia Milijaona Juliano Jonathan J Meshnick Steven R |
author_sort |
Mwapasa Victor |
title |
Nonradioactive heteroduplex tracking assay for the detection of minority-variant chloroquine-resistant Plasmodium falciparum in Madagascar |
title_short |
Nonradioactive heteroduplex tracking assay for the detection of minority-variant chloroquine-resistant Plasmodium falciparum in Madagascar |
title_full |
Nonradioactive heteroduplex tracking assay for the detection of minority-variant chloroquine-resistant Plasmodium falciparum in Madagascar |
title_fullStr |
Nonradioactive heteroduplex tracking assay for the detection of minority-variant chloroquine-resistant Plasmodium falciparum in Madagascar |
title_full_unstemmed |
Nonradioactive heteroduplex tracking assay for the detection of minority-variant chloroquine-resistant Plasmodium falciparum in Madagascar |
title_sort |
nonradioactive heteroduplex tracking assay for the detection of minority-variant chloroquine-resistant plasmodium falciparum in madagascar |
publisher |
BMC |
publishDate |
2009 |
url |
https://doi.org/10.1186/1475-2875-8-47 https://doaj.org/article/33bc0f27b93c4b73adaca334c30224eb |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
Malaria Journal, Vol 8, Iss 1, p 47 (2009) |
op_relation |
http://www.malariajournal.com/content/8/1/47 https://doaj.org/toc/1475-2875 doi:10.1186/1475-2875-8-47 1475-2875 https://doaj.org/article/33bc0f27b93c4b73adaca334c30224eb |
op_doi |
https://doi.org/10.1186/1475-2875-8-47 |
container_title |
Malaria Journal |
container_volume |
8 |
container_issue |
1 |
_version_ |
1766344796705652736 |