• Skip to primary navigation
  • Skip to main content
  • Skip to footer
  • Pessoal
    • Webmail
    • Área de Docentes
    • Área de Não-Docentes
  • Estudantes
    • Webmail
    • Moodle
    • NetP@
    • Biblioteca
    • Escola Doutoral
    • Serviços Académicos
    • Trabalhar no IHMT

IHMT

Instituto de Higiene e Medicina Tropical

  • O Instituto
    • Missão
    • História
    • Mensagem do Diretor
    • Órgãos de governo
    • Docentes e investigadores
    • Unidades de Ensino e de Investigação
  • Ensino
    • Doutoramentos
    • Mestrados
    • Cursos de Especialização
    • Formação transversal
    • Cursos de Curta Duração
    • Ensino à Distância
    • Apoio ao Desenvolvimento
    • Serviços académicos
  • Investigação
    • Centro GHTM
    • Unidade de Clínica Tropical
    • Unidade de Microbiologia Médica
    • Unidade de Parasitologia Médica
    • Unidade de Saúde Pública Global
    • Serviço de Interesse Comum
    • Biobanco
    • Centro Colaborador da OMS
    • Publicações
  • Serviços e gestão
    • Biblioteca
    • Sistema de Qualidade
    • Estatutos e regulamentos
    • Relatórios
    • Contratos públicos
    • Recursos humanos
      • Concursos e bolsas
      • Contratos
      • Avaliação e Desempenho
        • Processo Eleitoral da Comissão Paritária
      • Mobilidade
  • Doenças Tropicais
    • Consulta do Viajante
    • Glossário
    • Museu
    • Vídeos
    • MosquitoWeb
  • Comunidade
    • Cooperação e Desenvolvimento
    • Formação
    • Parcerias
  • Contactos
  • Português
  • English
Home / Publicações / In vitro chloroquine resistance for Plasmodium vivax isolates from the Western Brazilian Amazon

In vitro chloroquine resistance for Plasmodium vivax isolates from the Western Brazilian Amazon

  • Autores: Alecrim MG, Brasil LW, Chehuan YF, Costa JS, Costa MR, Lacerda MV, Melo GC, Monteiro WM, Nogueira F, Silveira H
  • Ano de Publicação: 2013
  • Journal: Malaria Journal
  • Link: http://www.malariajournal.com/content/12/1/226

Background

Chloroquine (CQ) and primaquine (PQ) are still the drugs of choice to treat Plasmodium vivax malaria in many endemic areas, Brazil included. There is in vivo evidence for the P. vivax resistance to CQ in the Brazilian Amazon, where the increase in the proportion of P. vivax malaria parallels the increase of unusual clinical complications related to this species. In this study, in vitro CQ and mefloquine (MQ)-susceptibility of P. vivax isolates from the Western Brazilian Amazon was tested using the double-site enzyme-linked lactate dehydrogenase immunodetection (DELI) assay.

Methods

A total of 112 P. vivax isolates were tested in vitro for CQ-susceptibility and out of these 47 were also tested for MQ-susceptibility. The DELI assay was used to detect P. vivax growth at 48-hour short-term culture in isolates with ring stages ranging from 50 to %. Each isolate was tested in triplicate and geometric means of IC50’s was obtained. Nineteen isolates were genetically characterized for pvdhfr, pvmrp1, pvmdr1 and pvdhps candidate genes likely related to CQ resistance (10 with IC50<40 nM and 9 with IC50 >100 nM).

Results

Twelve out of 112 isolates were considered resistant to CQ, resulting in 10.7% (IC95% 5.0-16.4), while 3 out of 47 (6.4%; IC95% 0.0-12.8) were resistant to MQ. A discrete correlation was observed between IC50’s of CQ and MQ (Spearman=0.294; p=0.045). For pvdhps gene, a non-synonymous mutation was found at codon 382 (S→C) in 5/8 CQ-sensitive samples and 1/9 CQ-resistant samples (p=0.027). The other molecular markers were not associated to CQ-susceptibility.

Conclusions

In vitro CQ-resistance estimated in this study, estimated by the DELI test, was very similar to that observed in clinical trials, suggesting that in vitro procedures developed by capable local laboratories are useful in the surveillance of CQ-resistance in the Amazon; concurrent Amazon P. vivax strains with both CQ and MQ resistance may be common; and a non-synonymous mutation at pvdhps codon 382 (S→C) was associated to in vitro susceptibility to CQ, needing further studies to be confirmed.

In vitro chloroquine resistance for Plasmodium vivax isolates from the Western Brazilian Amazon

  • Autores: Alecrim MG, Brasil LW, Chehuan YF, Costa JS, Costa MR, Lacerda MV, Melo GC, Monteiro WM, Nogueira F, Silveira H
  • Ano de Publicação: 2013
  • Journal: Malaria Journal
  • Link: http://www.malariajournal.com/content/12/1/226

Background

Chloroquine (CQ) and primaquine (PQ) are still the drugs of choice to treat Plasmodium vivax malaria in many endemic areas, Brazil included. There is in vivo evidence for the P. vivax resistance to CQ in the Brazilian Amazon, where the increase in the proportion of P. vivax malaria parallels the increase of unusual clinical complications related to this species. In this study, in vitro CQ and mefloquine (MQ)-susceptibility of P. vivax isolates from the Western Brazilian Amazon was tested using the double-site enzyme-linked lactate dehydrogenase immunodetection (DELI) assay.

Methods

A total of 112 P. vivax isolates were tested in vitro for CQ-susceptibility and out of these 47 were also tested for MQ-susceptibility. The DELI assay was used to detect P. vivax growth at 48-hour short-term culture in isolates with ring stages ranging from 50 to %. Each isolate was tested in triplicate and geometric means of IC50’s was obtained. Nineteen isolates were genetically characterized for pvdhfr, pvmrp1, pvmdr1 and pvdhps candidate genes likely related to CQ resistance (10 with IC50<40 nM and 9 with IC50 >100 nM).

Results

Twelve out of 112 isolates were considered resistant to CQ, resulting in 10.7% (IC95% 5.0-16.4), while 3 out of 47 (6.4%; IC95% 0.0-12.8) were resistant to MQ. A discrete correlation was observed between IC50’s of CQ and MQ (Spearman=0.294; p=0.045). For pvdhps gene, a non-synonymous mutation was found at codon 382 (S→C) in 5/8 CQ-sensitive samples and 1/9 CQ-resistant samples (p=0.027). The other molecular markers were not associated to CQ-susceptibility.

Conclusions

In vitro CQ-resistance estimated in this study, estimated by the DELI test, was very similar to that observed in clinical trials, suggesting that in vitro procedures developed by capable local laboratories are useful in the surveillance of CQ-resistance in the Amazon; concurrent Amazon P. vivax strains with both CQ and MQ resistance may be common; and a non-synonymous mutation at pvdhps codon 382 (S→C) was associated to in vitro susceptibility to CQ, needing further studies to be confirmed.

Footer

INSTITUTO DE HIGIENE E
MEDICINA TROPICAL
UNIVERSIDADE NOVA DE LISBOA
Rua da Junqueira, 100 1349-008 Lisboa
T +351 213 652 600
geral@ihmt.unl.pt

Consulta do Viajante e Medicina Tropical
T +351 213 652 630
T +351 213 652 690
T +351 91 182 37 48
T +351 91 182 44 67
medicina.viagens@ihmt.unl.pt

Ensino
Investigação
Medicina Tropical
Cooperação

Siga-nos

  • Facebook
  • LinkedIn
  • YouTube

Receber a “newsletter”

© Copyright 2023 IHMT-UNL Todos os Direitos Reservados.
  • Universidade Nova de Lisboa
  • Fundação para a Ciência e a Tecnologia

    Project UID/Multi/04413/2013