“基因筛查”加速利什曼病检测

生物谷

科学家开发了一种简单廉价的方法，用于大量筛查白蛉，从而确定它们是那种类型以及它们可能携带了何种利什曼原虫（导致利什曼病的病原体）。这项研究发表在了8月出版的《美国热带医学和卫生学杂志》上。

在利什曼病的流行地区监测宿主和利什曼原虫对于确定患者的疾病发作及结果和选择合适的疗法，以及评估该病传播到周围地区的可能性都是很重要的。

但是由于感染利什曼原虫的白蛉数量相对较少（甚至是在流行地区），为了获得有价值的数据，需要测试大量的标本。

传统的确定利什曼病宿主和利什曼原虫的物种类型的方法包括解剖和观察身体特征——这都需要相当多的时间和相当熟练的技能。

在日本山口大学的加藤大智领导的这项新研究中，他和同事开发了一种速度更快的方法。该方法通过检测特定基因的存在，从而确定宿主和利什曼原虫的类型。

他们检测了来自厄瓜多尔利什曼病流行区域的319只白蛉标本，在很短的时间里就在5只白蛉体内发现了利什曼原虫。

加藤告诉本网站说：“据我们所知，此前没有任何其它方法能用最小的工作量检验如此多的白蛉。”加藤说，目前该方法的成本是每份样本1美元，但是他们正在设法降低成本。

这项新技术目前正在用于阿根廷、厄瓜多尔和秘鲁的利什曼病流行区的流行病学研究。

苏丹喀土穆大学地方病研究所的研究员Hiba Salah-Eldin说这项新的技术将有助于科学家研究宿主—寄生虫关系，而且甚至可能有助于确定为什么只有某些白蛉能携带利什曼原虫。她说，确定一个地区白蛉携带利什曼原虫的能力，可能有助于预测潜在的流行。

Salah-Eldin还说这种方法还可能有助于防止漏检利什曼原虫的问题——许多科学家都遇到过这种困难。

英文原文：

'Gene screen' speeds up Leishmaniasis detection

The Leishmaniasis parasite

Wagdy Sawahel
15 August 2007
Source: SciDev.Net

Researchers have developed a simple and cheap method to screen large numbers of sand flies to determine their species and what type of Leishmania parasite — the microorganism that causes leishmaniasis — they might be carrying.

The study was published in the August issue of the American Journal of Tropical Medicine and Hygiene.

Monitoring both host and Leishmania parasite species in endemic regions is important for determining a patient's prognosis and choosing appropriate treatment, as well as for assessing the likelihood of the disease expanding to surrounding areas.

But because relatively few sand flies are infected with the Leishmania parasite — even in endemic areas — a large number of specimens have to be tested to get any informative data.

Conventional methods for determining host and Leishmania parasite species include dissection and observation of physical characteristics — both of which require considerable time and skill.

Lead researcher Hirotomo Kato, from the Japan-based Yamaguchi University, and colleagues have developed a faster method that tests for the presence of a certain genes to determine host and parasite species.

They were able to test 319 sand fly specimens captured from endemic areas of Ecuador, and detect the parasite in five of them in a short space of time.

"To our knowledge, there are not any other methods to analyse such numbers of sand flies individually with minimum effort," Kato told SciDev.Net.

The method costs about US$1 per sample, but they are trying to reduce this, said Kato.

The new technique is currently being used for epidemiological studies in endemic areas of Argentina, Ecuador and Peru.

Hiba Salah-Eldin, a researcher at the Institute of Endemic Diseases at the Sudan-based University of Khartoum said this new technique will help scientists study the host-parasite relationship, and possibly even help to determine why only some species of sand fly are capable of carrying Leishmania.

Determining the capacity of sand flies in an area to carry Leishmania could help predict potential epidemics, she said.

Salah-Eldin said this method could also help prevent the problem of failing to detect parasites — a difficulty many researchers experience.

Link to abstract in the American Journal of Tropical Medicine and Hygiene

Reference: American Journal of Tropical Medicine and Hygiene 77, 324 (2007)

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