Monitoring chloroquine resistance using Plasmodium falciparum parasites isolated from wild mosquitoes in Tanzania.
スポンサーリンク
概要
- 論文の詳細を見る
Monitoring antimalarial drug resistance is a useful epidemiologic tool and provides early detection of resistance foci. Using DNA extracted from the head/thorax of wild mosquitoes collected from Bagamoyo Coastal Tanzania, samples infected by Plasmodium falciparum (N = 89, in 2002 and N = 249 in 2004) were screened by nested polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) assay for mutations at Pfcrt76 and Pfmdr1-86 associated with chloroquine (CQ) resistance. The majority of isolates were of single infection (71%), and the prevalence of mutant alleles of Pfcrt76 decreased from 64.5% in 2002 to 16% in 2004; likewise, mutant Pfmdr1-86 alleles decreased from 46.6% to 2.7%. Overall, there was a decline of mutant isolates by a factor of 17 and 4 for Pfmdr1 and Pfcrt, respectively. In contrast, isolates with wild-type alleles increased significantly from < 20% in 2002 to 67.6% for Pfcrt76 and 83.5% for Pfmdr1-86 in 2004. This observation suggest a biologic trend of decrease of CQ mutants and a subsequent increase of CQ susceptible parasites in circulation after the discontinued use of CQ in 2001 as a first-line drug in Tanzania. High prevalence of susceptible P. falciparum found in circulation not only supports other reports of a decline of mutant parasites after a reduction of drug selection pressure but suggests that the fitness cost is high in mutant parasites. Typing parasite isolates from infected mosquitoes, an alternative means of data collection, has the potential to increase the spatial and temporal coverage, and this approach is practical in highly endemic regions of Africa.
論文 | ランダム
- 222 軟鋼板のスポット溶接部の金属組織についての一考察 : ナゲット外柱状様組織に関する研究
- 221 スポット溶接機の機械的特性と溶接品質との関連性について(第6報) : 板ばねを挿入したスポ・ゾト溶接機の場合の電極寿命
- 113 磁気駆動アーク溶接に関する研究(第5報) : 溶接電流の通電パターンの制御による継手品質の改善
- 9155 今世紀初頭フィンランドにおける中層都市住居の建設について : H.カールティネンの例に見る建設工匠の活動(建築歴史・意匠)
- 磁気駆動アーク溶接におけるアークの回転挙動についての実験的研究