LeishmanCeres Laboratory (GLP Compliance Certified), Parasitology Unit, Veterinary Faculty, University of Extremadura, Avenida de la Universidad s/n, 10003 Cáceres, Spain.
Vet Parasitol. 2013 Feb 18;192(1-3):43-50. doi: 10.1016/j.vetpar.2012.11.007. Epub 2012 Nov 12.
It is known that hair can accumulate environmental toxics and excrete foreign chemical or biological substances. In this context, we hypothesized that foreign DNA could be found in the hair of an infected organism, and thus, be detected by Real Time PCR in the hair of Leishmania infantum naturally infected dogs. A population of 28 dogs living in Leishmania endemic areas was divided into two groups: A (13 Leishmania infected dogs) and B (15 healthy dogs). Blood, lymph node and ear hair samples from all of them were tested for the presence of parasite kinetoplast DNA (kDNA). For the same purpose, hair of several body areas and hair sections of two infected dogs were also analyzed. Epidermal keratinocytes from an infected animal were also analyzed for reactivity against Leishmania antigens by ELISA and for the presence of kDNA. Regarding to dogs from group A, parasite kDNA was detected in the 100% of lymph node samples. The sensitivity of Real Time PCR in ear hair was similar to that obtained in blood (9 positive out of 13 versus 8 positive out of 13, respectively). Moreover, the presence of L. infantum kDNA was also detected in the hair of all the analyzed body zones, in all hair sections and in epidermal keratinocytes. In infected dogs, parasite kDNA could be detected and quantified from just one single hair, whereas it was not detected in any of the samples of the healthy dogs. This work describes a new method for a reliable and non-invasive diagnosis of canine leishmaniosis using hair samples of infected animals. The data presented also provide some insights for the understanding of the physiology of keratinocytes and the role of hair as a specialized tissue in the kidnapping and removal of foreign DNA.
已知毛发可以积累环境毒物并排出外来的化学或生物物质。在此背景下，我们假设感染生物体的毛发中可能存在外来 DNA，并可通过实时 PCR 在自然感染利什曼原虫的犬只的毛发中检测到。将生活在利什曼病流行地区的 28 只犬分为两组：A 组（13 只利什曼原虫感染犬）和 B 组（15 只健康犬）。对所有犬的血液、淋巴结和耳毛样本进行寄生虫动基体 DNA（kDNA）检测。出于同样的目的，还分析了几只身体部位的毛发和两只感染犬的毛发切片。还通过 ELISA 分析了来自感染动物的表皮角质形成细胞对利什曼原虫抗原的反应性和 kDNA 的存在。关于 A 组的犬，在 100%的淋巴结样本中检测到寄生虫 kDNA。耳毛实时 PCR 的灵敏度与血液中的灵敏度相似（13 只犬中有 9 只阳性与 13 只犬中有 8 只阳性）。此外，还在所有分析的身体区域的毛发、所有毛发切片和表皮角质形成细胞中检测到了利什曼原虫 kDNA。在感染犬中，仅从一根毛发即可检测到寄生虫 kDNA 并对其进行定量，而在任何健康犬的样本中均未检测到寄生虫 kDNA。本研究描述了一种使用感染动物毛发样本可靠且非侵入性诊断犬利什曼病的新方法。所提供的数据还为理解角质形成细胞的生理学以及毛发作为一种特殊组织在劫持和去除外来 DNA 方面的作用提供了一些见解。
