Kosaisavee Varakorn, Suwanarusk Rossarin, Nosten François, Kyle Dennis E, Barrends Marion, Jones James, Price Ric, Russell Bruce, Lek-Uthai Usa
Faculty of Public Health, Mahidol University, Bangkok, Thailand.
Exp Parasitol. 2006 Sep;114(1):34-9. doi: 10.1016/j.exppara.2006.02.006. Epub 2006 Mar 20.
In vitro susceptibility tests provide information on the intrinsic response of Plasmodium vivax to antimalarials, free from confounding factors such as host immunity or relapse. This study examined the utility of radioisotope and PicoGreen assays as alternatives to the traditional microscopic examination for assessing response of P. vivax to antimalarial drugs. There was no significant difference in the mean chloroquine IC(50) of P. vivax (n=40) as determined by the microscopic (33.4 ng/ml), isotopic (33.6 ng/ml), and PicoGreen (39.1 ng/ml) assays, respectively (F=0.239, df=2, 51, and p=0.788). However measurement of IC(50)s by the microscopic method was slightly more successful in producing valid assays (57%), compared to the isotopic (32.5%) and PicoGreen (45.5%) methods. In a paired comparison of 20 fresh and cryopreserved isolates as examined by the microscopic method, there were no significant differences between the mean IC(50) responses (T=1.58, df=15, and p=0.34). Detailed methodologies for the short time culture of field and cryopreserved P. vivax are described. Although the microscopic in vitro assay provides a useful method for characterizing the drug susceptibility phenotype of P. vivax isolates, its utility is limited by a laborious methodology and need for highly skilled microscopists. Future efforts should focus on further development of high throughput assays such as the PicoGreen assay as described in this study.
体外药敏试验可提供有关间日疟原虫对抗疟药的内在反应信息，不受宿主免疫或复发等混杂因素影响。本研究检验了放射性同位素法和PicoGreen分析法作为传统显微镜检查替代方法来评估间日疟原虫对抗疟药物反应的实用性。分别通过显微镜检查法（33.4纳克/毫升）、同位素法（33.6纳克/毫升）和PicoGreen分析法（39.1纳克/毫升）测定的间日疟原虫（n = 40）的平均氯喹IC(50)值无显著差异（F = 0.239，自由度= 2, 51，p = 0.788）。然而，与同位素法（32.5%）和PicoGreen分析法（45.5%）相比，通过显微镜检查法测定IC(50)值在产生有效试验方面略更成功（57%）。在通过显微镜检查法对20个新鲜和冷冻保存的分离株进行的配对比较中，平均IC(50)反应之间无显著差异（T = 1.58，自由度= 15，p = 0.34）。描述了野外和冷冻保存的间日疟原虫短期培养的详细方法。虽然显微镜体外试验为表征间日疟原虫分离株的药物敏感性表型提供了一种有用方法，但其实用性受到繁琐方法和对高技能显微镜人员需求的限制。未来的努力应集中于进一步开发本研究中所述的高通量分析方法，如PicoGreen分析法。
