Temporal changes in Plasmodium falciparum anti-malarial drug sensitivity in vitro and resistance-associated genetic mutations in isolates from Papua New Guinea
Background: In northern Papua New Guinea (PNG), most Plasmodium falciparum isolates proved resistant to chloroquine (CQ) in vitro between 2005 and 2007, and there was near-fixation of pfcrt K76T, pfdhfr C59R/S108N and pfmdr1 N86Y. To determine whether the subsequent introduction of artemisinin combi...
| Main Authors: | , , , , , , , , , , , , , , |
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| Format: | Journal Article |
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BioMed Central
2015
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| Online Access: | http://hdl.handle.net/20.500.11937/16467 |
| _version_ | 1848749185062404096 |
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| author | Koleala, T. Karl, S. Laman, M. Moore, Brioni Benjamin, J. Barnadas, C. Robinson, L. Kattenberg, J. Javati, S. Wong, R. Rosanas-Urgell, A. Betuela, I. Siba, P. Mueller, I. Davis, T. |
| author_facet | Koleala, T. Karl, S. Laman, M. Moore, Brioni Benjamin, J. Barnadas, C. Robinson, L. Kattenberg, J. Javati, S. Wong, R. Rosanas-Urgell, A. Betuela, I. Siba, P. Mueller, I. Davis, T. |
| author_sort | Koleala, T. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Background: In northern Papua New Guinea (PNG), most Plasmodium falciparum isolates proved resistant to chloroquine (CQ) in vitro between 2005 and 2007, and there was near-fixation of pfcrt K76T, pfdhfr C59R/S108N and pfmdr1 N86Y. To determine whether the subsequent introduction of artemisinin combination therapy (ACT) and reduced CQ-sulphadoxine-pyrimethamine pressure had attenuated parasite drug susceptibility and resistance-associated mutations, these parameters were re-assessed between 2011 and 2013. Methods: A validated fluorescence-based assay was used to assess growth inhibition of 52 P. falciparum isolates from children in a clinical trial in Madang Province. Responses to CQ, lumefantrine, piperaquine, naphthoquine, pyronaridine, artesunate, dihydroartemisinin, artemether were assessed. Molecular resistance markers were detected using a multiplex PCR ligase detection reaction fluorescent microsphere assay. Results: CQ resistance (in vitro concentration required for 50% parasite growth inhibition (IC50) >100 nM) was present in 19% of isolates. All piperaquine and naphthoquine IC50s were <100 nM and those for lumefantrine, pyronaridine and the artemisinin derivatives were in low nM ranges. Factor analysis of IC50s showed three groupings (lumefantrine; CQ, piperaquine, naphthoquine; pyronaridine, dihydroartemisinin, artemether, artesunate). Most isolates (96%) were monoclonal pfcrt K76T (SVMNT) mutants and most (86%) contained pfmdr1 N86Y (YYSND). No wild-type pfdhfr was found but most isolates contained wild-type (SAKAA) pfdhps. Compared with 2005-2007, the geometric mean (95% CI) CQ IC50 was lower (87 (71-107) vs 167 (141-197) nM) and there had been no change in the prevalence of pfcrt K76T or pfmdr1 mutations. There were fewer isolates of the pfdhps (SAKAA) wild-type (60 vs 100%) and pfdhfr mutations persisted. Conclusions: Reflecting less drug pressure, in vitro CQ sensitivity appears to be improving in Madang Province despite continued near-fixation of pfcrt K76T and pfmdr1 mutations. Temporal changes in IC50s for other anti-malarial drugs were inconsistent but susceptibility was preserved. Retention or increases in pfdhfr and pfdhps mutations reflect continued use of sulphadoxine-pyrimethamine in the study area including through paediatric intermittent preventive treatment. The susceptibility of local isolates to lumefantrine may be unrelated to those of other ACT partner drugs. Trial registration: Australian New Zealand Clinical Trials Registry ACTRN12610000913077. |
| first_indexed | 2025-11-14T07:16:55Z |
| format | Journal Article |
| id | curtin-20.500.11937-16467 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T07:16:55Z |
| publishDate | 2015 |
| publisher | BioMed Central |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-164672017-09-13T15:04:45Z Temporal changes in Plasmodium falciparum anti-malarial drug sensitivity in vitro and resistance-associated genetic mutations in isolates from Papua New Guinea Koleala, T. Karl, S. Laman, M. Moore, Brioni Benjamin, J. Barnadas, C. Robinson, L. Kattenberg, J. Javati, S. Wong, R. Rosanas-Urgell, A. Betuela, I. Siba, P. Mueller, I. Davis, T. Background: In northern Papua New Guinea (PNG), most Plasmodium falciparum isolates proved resistant to chloroquine (CQ) in vitro between 2005 and 2007, and there was near-fixation of pfcrt K76T, pfdhfr C59R/S108N and pfmdr1 N86Y. To determine whether the subsequent introduction of artemisinin combination therapy (ACT) and reduced CQ-sulphadoxine-pyrimethamine pressure had attenuated parasite drug susceptibility and resistance-associated mutations, these parameters were re-assessed between 2011 and 2013. Methods: A validated fluorescence-based assay was used to assess growth inhibition of 52 P. falciparum isolates from children in a clinical trial in Madang Province. Responses to CQ, lumefantrine, piperaquine, naphthoquine, pyronaridine, artesunate, dihydroartemisinin, artemether were assessed. Molecular resistance markers were detected using a multiplex PCR ligase detection reaction fluorescent microsphere assay. Results: CQ resistance (in vitro concentration required for 50% parasite growth inhibition (IC50) >100 nM) was present in 19% of isolates. All piperaquine and naphthoquine IC50s were <100 nM and those for lumefantrine, pyronaridine and the artemisinin derivatives were in low nM ranges. Factor analysis of IC50s showed three groupings (lumefantrine; CQ, piperaquine, naphthoquine; pyronaridine, dihydroartemisinin, artemether, artesunate). Most isolates (96%) were monoclonal pfcrt K76T (SVMNT) mutants and most (86%) contained pfmdr1 N86Y (YYSND). No wild-type pfdhfr was found but most isolates contained wild-type (SAKAA) pfdhps. Compared with 2005-2007, the geometric mean (95% CI) CQ IC50 was lower (87 (71-107) vs 167 (141-197) nM) and there had been no change in the prevalence of pfcrt K76T or pfmdr1 mutations. There were fewer isolates of the pfdhps (SAKAA) wild-type (60 vs 100%) and pfdhfr mutations persisted. Conclusions: Reflecting less drug pressure, in vitro CQ sensitivity appears to be improving in Madang Province despite continued near-fixation of pfcrt K76T and pfmdr1 mutations. Temporal changes in IC50s for other anti-malarial drugs were inconsistent but susceptibility was preserved. Retention or increases in pfdhfr and pfdhps mutations reflect continued use of sulphadoxine-pyrimethamine in the study area including through paediatric intermittent preventive treatment. The susceptibility of local isolates to lumefantrine may be unrelated to those of other ACT partner drugs. Trial registration: Australian New Zealand Clinical Trials Registry ACTRN12610000913077. 2015 Journal Article http://hdl.handle.net/20.500.11937/16467 10.1186/s12936-015-0560-3 BioMed Central fulltext |
| spellingShingle | Koleala, T. Karl, S. Laman, M. Moore, Brioni Benjamin, J. Barnadas, C. Robinson, L. Kattenberg, J. Javati, S. Wong, R. Rosanas-Urgell, A. Betuela, I. Siba, P. Mueller, I. Davis, T. Temporal changes in Plasmodium falciparum anti-malarial drug sensitivity in vitro and resistance-associated genetic mutations in isolates from Papua New Guinea |
| title | Temporal changes in Plasmodium falciparum anti-malarial drug sensitivity in vitro and resistance-associated genetic mutations in isolates from Papua New Guinea |
| title_full | Temporal changes in Plasmodium falciparum anti-malarial drug sensitivity in vitro and resistance-associated genetic mutations in isolates from Papua New Guinea |
| title_fullStr | Temporal changes in Plasmodium falciparum anti-malarial drug sensitivity in vitro and resistance-associated genetic mutations in isolates from Papua New Guinea |
| title_full_unstemmed | Temporal changes in Plasmodium falciparum anti-malarial drug sensitivity in vitro and resistance-associated genetic mutations in isolates from Papua New Guinea |
| title_short | Temporal changes in Plasmodium falciparum anti-malarial drug sensitivity in vitro and resistance-associated genetic mutations in isolates from Papua New Guinea |
| title_sort | temporal changes in plasmodium falciparum anti-malarial drug sensitivity in vitro and resistance-associated genetic mutations in isolates from papua new guinea |
| url | http://hdl.handle.net/20.500.11937/16467 |