RESUMO
Monitoring of multidrug-resistant (MDR)falciparum and vivax malaria has recently been included in the Global Plan for Artemisinin Resistance Containment (GPARC) of the Greater Mekong Sub-region, particularly at the Thailand-Cambodia and Thailand-Myanmar borders. In parallel to GPARC, monitoring MDR malaria parasites in anopheline vectors is an ideal augment to entomological surveillance. Employing Plasmodium- and species-specific nested PCR techniques, only P. vivax was detected in 3/109 salivary gland DNA extracts of anopheline vectors collected during a rainy season between 24-26 August 2009 and 22-24 September 2009 and a dry season between 29-31 December 2009 and 16-18 January 2010. Indoor and out- door resting mosquitoes were collected in Thong Pha Phum District, Kanchanaburi Province (border of Thailand-Myanmar) and Bo Rai District, Trat Province (border of Thailand-Cambodia): one sample from Anopheles dirus at the Thailand-Cambodia border and two samples from An. aconitus from Thailand-Myanmar border isolate. Nucleotide sequencing of dihydrofolate reductase gene revealed the presence in all three samples of four mutations known to cause high resistance to antifolate pyrimethamine, but no mutations were found in multidrug resistance transporter 1 gene that are associated with (falciparum) resistance to quinoline antimalarials. Such findings indicate the potential usefulness of this approach in monitoring the prevalence of drug-resistant malaria parasites in geographically regions prone to the development of drug resistance and where screening of human population at risk poses logistical and ethical problems. Keywords: Anopheles spp, Plasmodium vivax, antimalarial resistance, Greater Mekong Sub-region, nested PCR, vector surveillance
Assuntos
Anopheles/parasitologia , Resistência a Múltiplos Medicamentos , Insetos Vetores/parasitologia , Plasmodium vivax/efeitos dos fármacos , Plasmodium vivax/isolamento & purificação , Animais , Antimaláricos/farmacologia , Artemisininas/farmacologia , Camboja/epidemiologia , Humanos , Malária Vivax/tratamento farmacológico , Malária Vivax/epidemiologia , Malária Vivax/parasitologia , Mianmar/epidemiologia , Reação em Cadeia da Polimerase , Quinolinas/farmacologia , Análise de Sequência de DNA , Tailândia/epidemiologiaRESUMO
H-, K- and N-ras gene mutations were analyzed in lung cancer from Thai patients. Thirteen out of 58 cases (22%) harbored the mutations. Ten cases showed K-ras gene mutations at codon 12, 1 case presented a mutation at codon 13 and another case exhibited a mutation at codon 63. Silent mutations of N-ras gene in codons 57 and 62 were seen in one patient, whilst no H-ras mutation was found in these patients. Bases change in K-ras gene were G right curved arrow T transversion (62%), G right curved arrow A transition (15%) and G right curved arrow C transition (15%), whereas T right curved arrow G transversion and A right curved arrow G transition were detected in N-ras mutant gene.