Divina B P, Wilhelmsson E, Mattsson J G, Waller P, Höglund J
Department of Parasitology (SWEPAR), National Veterinary Institute and Swedish University of Agricultural Sciences, Uppsala.
Parasitology. 2000 Aug;121 ( Pt 2):193-201. doi: 10.1017/s0031182099006162.
Lungworms of the genus Dictyocaulus from cattle, roe deer, and moose in Sweden were subjected to morphological and molecular analyses. The objectives of the study were to investigate whether mixed or monospecific Dictyocaulus infections occur in Swedish cattle and whether wild cervids may act as reservoirs. The morphological characters examined were thickness and shape of the buccal capsule wall (BCW) and total spicular length (TSL). Morphometry was also done on the total body length, and BCW thickness and length. In the molecular identification, we used a PCR-linked hybridization assay to probe worm DNA with species-specific oligonucleotide probes to the second internal transcribed spacer (1TS2). The results showed that the BCW shape was the most reliable morphological character for identification. Significant differences were observed in this character, but an overlap occurred between lungworms from each of the host species. With the hybridization assay, all lungworms from cattle were identified as D. viviparus, whereas those from roe deer represented a novel Dictyocaulus species demonstrating that each host had a monospecific lungworm infection. In moose, 61 (78.2%) worms belonged to the new species and 17 (21.8%) were D. eckerti. This study shows the usefulness of hybridization assay as an epidemiological tool for the specific identification of lungworms of cattle and wild cervids.
对瑞典牛、狍和驼鹿体内的网尾线虫属肺线虫进行了形态学和分子分析。该研究的目的是调查瑞典牛是否发生混合或单一物种的网尾线虫感染，以及野生鹿类是否可能作为储存宿主。所检查的形态特征包括口囊壁（BCW）的厚度和形状以及总交合刺长度（TSL）。还对虫体全长、BCW厚度和长度进行了形态测量。在分子鉴定中，我们使用了一种与PCR相关的杂交试验，用物种特异性寡核苷酸探针探测虫体DNA的第二个内部转录间隔区（1TS2）。结果表明，BCW形状是最可靠的形态学鉴定特征。在这一特征上观察到显著差异，但每个宿主物种的肺线虫之间存在重叠。通过杂交试验，所有来自牛的肺线虫被鉴定为胎生网尾线虫，而来自狍的肺线虫代表一个新的网尾线虫物种，表明每个宿主都有单一物种的肺线虫感染。在驼鹿中，61条（78.2%）线虫属于新物种，17条（21.8%）为埃氏网尾线虫。这项研究表明杂交试验作为一种流行病学工具，对于牛和野生鹿类肺线虫的特异性鉴定是有用的。
