RESUMO
The aim of this work was to define the cause of sulfadoxine/pyrimethamine (SP) treatment failure in Plasmodium falciparum infections in a malaria-endemic zone of India. Samples were collected from 176 patients in Kolkata from November 2008 to July 2009. In vitro susceptibility testing was performed on all isolates. Parasite DNA was extracted, and PCR and restriction fragment length polymorphism (RFLP) analysis of different codons of the dhfr gene (16, 51, 59, 108 and 164) and dhps gene (436, 437, 540, 581 and 613) were performed. Finally, sequencing of the products was performed to confirm the mutations. The in vivo treatment response to SP among the 176 patients was determined. A novel mutation of isoleucine was observed at codon 108 of the dhfr gene, which was highly correlated with in vitro SP resistance as well as early treatment failure. A double dhfr mutation (108I+51I) was observed in 77.3% of isolates, and triple mutation of the dhps gene was observed in 18.2% of isolates. In this endemic zone, SP treatment failure is due to a novel dhfr mutation (108I+51I) and any one of the dhps mutations (S436A, A437G, A581G or A613T/S). An increase in these mutations was highly correlated with SP resistance (P < 0.0001).
Assuntos
Antimaláricos/administração & dosagem , Resistência a Medicamentos , Malária Falciparum/tratamento farmacológico , Malária Falciparum/parasitologia , Mutação de Sentido Incorreto , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/genética , Tetra-Hidrofolato Desidrogenase/genética , Adulto , Criança , Pré-Escolar , DNA de Protozoário/genética , Humanos , Índia , Testes de Sensibilidade Parasitária , Plasmodium falciparum/isolamento & purificação , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Análise de Sequência de DNA , Falha de TratamentoRESUMO
OBJECTIVE: To evaluate the anti-folate (sulphadoxine)-resistant pattern in Kolkata, one of the malaria endemic zones of Eastern India. METHODS: At first, 107 P. falciparum suspected cases were enrolled in this study. Ninety isolates (84.11%) of 107 suspected cases were analysed, as they had mono-infection with P. falciparum. In vitro susceptibility assays were performed in all 90 isolates. Parasitic DNA was isolated by phenol-chloroform extraction method and polymerase chain reaction was followed by restriction fragment length polymorphism analysis of different codons of the pfdhps gene (436, 437, 540, 581 and 613). RESULTS: Among 90 isolates from Kolkata, dhps mutant isolates at codons 436, 437, 540, 581 and 613 were found in 53.33%, 67.78%, 46.66%, 15.56% and 45.55%, respectively. In vitro sulphadoxine resistance was found in 49 isolates (54.44%). Interestingly we found 33 isolates (36.67%) with quadruple AGEAT mutant allele, of which 32 isolates (96.97%) were highly sulphadoxine resistant (P < 0.01) in vitro. CONCLUSION: Our present findings implicate that because of enormous drug (sulphfadoxine) pressure, novel AGEAT mutation was highly correlated (P < 0.01) with sulphadoxine resistance.
Assuntos
Di-Hidropteroato Sintase/genética , Malária Falciparum/genética , Mutação , Plasmodium falciparum/genética , Proteínas de Protozoários/genética , Antimaláricos/uso terapêutico , DNA de Protozoário/genética , Resistência a Medicamentos , Genótipo , Humanos , Índia , Malária Falciparum/tratamento farmacológico , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Sulfadoxina/uso terapêuticoRESUMO
An intrafamilial outbreak in West Bengal, India, involving 5 deaths and person-to-person transmission was attributed to Nipah virus. Full-genome sequence of Nipah virus (18,252 nt) amplified from lung tissue showed 99.2% nt and 99.8% aa identity with the Bangladesh-2004 isolate, suggesting a common source of the virus.
