Referral Veterinary Diagnostic and Extension Centre, Lala Lajpat Rai University of Veterinary and Animal Sciences, Karnal, Haryana, 132001, India.
Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, Haryana, 125001, India.
Parasitol Res. 2021 Jun;120(6):2047-2056. doi: 10.1007/s00436-021-07163-2. Epub 2021 Apr 24.
Nematodes of the genus Physaloptera are globally distributed and infect a multitude of hosts. Their life cycle involves orthopterans and coleopterans as intermediate hosts. The morphological characters alone are inadequate to detect and differentiate Physaloptera spp. from its congeners. Moreover, molecular studies are limited to compare them precisely. The present communication reports the first molecular phylogenetic characterization of feline Physaloptera spp. from India based on mitochondrial cytochrome c oxidase subunit 1 (COX1) and small subunit ribosomal DNA (18S rDNA). The nematodes were first isolated from the stomach of adult stray cats during necropsy examination. Based on the gross and microscopic characters, the worms were identified as P. praeputialis. Morphological identification was further confirmed through PCR targeting the barcode region of the mitochondrial cytochrome c oxidase subunit I (MT-COI) gene, using nematode-specific primers cocktail followed by species specific primers targeting partial COX1 and 18S rRNA genes. Generated sequences were submitted in NCBI GenBank (MW517846, MW410927, MW411349), and phylogenetic trees were constructed using the maximum likelihood method. When compared with other sequences of Physaloptera species across the globe, the present isolates showed 85.6-97.7% and 97.3-99% nucleotide homology based on COX1 and 18S rRNA gene, respectively. BLASTn analysis revealed a strong identity to other Physaloptera spp., and the phylogenetic tree placed all Physaloptera spp. in the same cluster. This study again indicates the usefulness of molecular techniques to substantiate the identity of species that may lack adequate descriptions and impart new insight for the potentially overlooked significance of P. praeputialis infections in felines.
Physaloptera 属的线虫在全球范围内分布，并感染多种宿主。它们的生命周期涉及直翅目和鞘翅目作为中间宿主。仅形态特征不足以检测和区分 Physaloptera 属及其近缘种。此外，分子研究仅限于进行精确比较。本通讯报道了基于线粒体细胞色素 c 氧化酶亚基 1（COX1）和小亚基核糖体 DNA（18S rDNA）对来自印度的猫科 Physaloptera 属的首次分子系统发育特征描述。这些线虫最初是在尸检检查时从成年流浪猫的胃中分离出来的。根据大体和微观特征，这些蠕虫被鉴定为 P. praeputialis。通过针对线粒体细胞色素 c 氧化酶亚基 I（MT-COI）基因的条形码区域的 PCR 进一步确认形态识别，使用线虫特异性引物混合物，然后使用针对部分 COX1 和 18S rRNA 基因的特异性引物。生成的序列在 NCBI GenBank 中提交（MW517846、MW410927、MW411349），并使用最大似然法构建了系统发育树。与全球其他 Physaloptera 种的序列相比，本分离株在 COX1 和 18S rRNA 基因上分别显示出 85.6-97.7%和 97.3-99%的核苷酸同源性。BLASTn 分析显示与其他 Physaloptera spp. 具有很强的同一性，系统发育树将所有 Physaloptera spp. 置于同一聚类中。这项研究再次表明分子技术对于证实可能缺乏充分描述的物种的身份非常有用，并为 P. praeputialis 感染在猫科动物中的潜在被忽视的意义提供新的见解。
