Panda Rasmita, Nehra Anil Kumar, Ram Hira, Karikalan Mathesh, Kumari Priyanka, Garg Rajat, Banerjee Partha Sarathi, Pawde Abhijit, Sharma Aditi, Gupta Mukesh, Singh Raj Kumar
Division of Parasitology, ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India.
Division of Parasitology, ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India; Department of Veterinary Parasitology, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, Haryana, India.
J Genet Eng Biotechnol. 2025 Sep;23(3):100512. doi: 10.1016/j.jgeb.2025.100512. Epub 2025 May 26.
The Trichinella species complex includes 10 recognized species and three genotypes with global distribution, impacting significant health and economic burdens on livestock, wildlife, and humans. In India, trichinellosis is an under recognized zoonotic disease. Investigating the taxonomic status, genetic diversity and phylogeography of Indian Trichinella isolates is crucial for understanding the disease's regional dynamics. This study used International Commission on Trichinellosis (ICT) recommended multiplex PCR (mPCR) followed by sequencing for identification of the Indian Trichinella isolates up to species level. Multiplex PCR assay yielded band pattern similar to either single infection with T. nelsoni or mixed with T. britovi in leopards and tigers. However, sequencing of mPCR products revealed an increase in base composition. Further molecular characterization was performed using five nuclear genes/regions (18S rRNA, 5S ISR, ESV, ITS1, and ITS2), and three mitochondrial genes (coxI, cytb, and mt-lsr). Phylogenetic analyses (maximum likelihood and Bayesian inference) based on the molecular markers (coxI, 5S ISR, ITS1, and ITS2) highlighted the genetic variation among the Indian isolates, and positioned them as sister clades to T. britovi or T. nelsoni or as an independent taxon. Furthermore, the variable region of ESV also presented a series of unique nucleotides in the Indian isolates which unequivocally differentiated them from known T. nelsoni and T. britovi sequences. Based on the molecular data, six isolates were identified as T. nelsoni-like species, designated as T14 genotype; one isolate with a unique genotype, labelled as genotype T15; and three isolates exhibited mixed infections of T. britovi and the T14 genotype. This study suggests the presence of two novel Trichinella genotypes, T14 and T15, each with distinct genetic profile, emphasizing the role of leopards and tigers as sentinel hosts for Trichinella in India.
旋毛虫物种复合体包括10个公认的物种和3个基因型，分布于全球，给家畜、野生动物和人类带来了重大的健康和经济负担。在印度，旋毛虫病是一种未得到充分认识的人畜共患病。调查印度旋毛虫分离株的分类地位、遗传多样性和系统地理学，对于了解该疾病的区域动态至关重要。本研究采用旋毛虫病国际委员会（ICT）推荐的多重PCR（mPCR），随后进行测序，以鉴定印度旋毛虫分离株至物种水平。多重PCR检测在豹和虎中产生的条带模式类似于单感染纳氏旋毛虫或与布氏旋毛虫混合感染。然而，mPCR产物的测序显示碱基组成有所增加。使用五个核基因/区域（18S rRNA、5S ISR、ESV、ITS1和ITS2）和三个线粒体基因（coxI、cytb和mt-lsr）进行了进一步的分子特征分析。基于分子标记（coxI、5S ISR、ITS1和ITS2）的系统发育分析（最大似然法和贝叶斯推断）突出了印度分离株之间的遗传变异，并将它们定位为布氏旋毛虫或纳氏旋毛虫的姐妹进化枝，或作为一个独立的分类单元。此外，ESV的可变区在印度分离株中也呈现出一系列独特的核苷酸，这明确地将它们与已知的纳氏旋毛虫和布氏旋毛虫序列区分开来。基于分子数据，六个分离株被鉴定为类纳氏旋毛虫物种，指定为T14基因型；一个具有独特基因型的分离株，标记为T15基因型；三个分离株表现出布氏旋毛虫和T14基因型的混合感染。本研究表明存在两种新的旋毛虫基因型，T14和T15，每种基因型都有独特的遗传特征，强调了豹和虎作为印度旋毛虫哨兵宿主的作用。
