ABSTRACT
PURPOSE: The aim of the present study was to carry out a detailed study of morphological features and to determine the phylogenetic position of Parabronema smithii (Cobbold, 1882) found in wild elephants in Sri Lanka. METHODS: Adult worms were collected from stomach ulcers at postmortem examination of wild elephants in the Udawalawe National Park, Sri Lanka. The detailed morphology of P. smithii was studied using light microscopy and, for the first time, scanning electron microscopy. Fifteen morphological characteristics were investigated. The phylogenetic analysis was conducted using the second internal transcribed spacer region (ITS2), and portions of the large subunit ribosomal DNA (28S) and cytochrome c oxidase subunit 1 (cox1). Furthermore, the present study provides a comparison of morphology and morphometrics of Parabronema species that occur in different hosts. CONCLUSION: Parabronema smithii isolated from wild elephants exhibited the key morphological features. Phylogenetic analysis of selected genes revealed that P. smithii is closely associated with P. skrjabini and Habronema spp. Findings of the present study enhance our understanding of the biology and taxonomy of P. smithii in wild elephant in Sri Lanka and will contribute to future phylogeographic studies.
Subject(s)
Animals, Wild/parasitology , Elephants/parasitology , Spirurida Infections/veterinary , Spirurina/genetics , Spirurina/ultrastructure , Animals , Autopsy/veterinary , Bayes Theorem , Cytochromes c1/genetics , DNA, Helminth/chemistry , DNA, Helminth/isolation & purification , DNA, Intergenic/chemistry , DNA, Intergenic/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Female , Male , Markov Chains , Microscopy, Electron, Scanning/veterinary , Monte Carlo Method , Phylogeny , RNA, Ribosomal, 28S/genetics , Spirurida Infections/parasitology , Spirurina/classification , Sri Lanka , Stomach/parasitology , Stomach Ulcer/parasitology , Stomach Ulcer/veterinaryABSTRACT
Fasciola jacksoni is a significant contributor to the health and mortality of Asian elephants, particularly those in Sri Lanka. Despite the impact of fascioliasis on elephant populations, it is a neglected veterinary disease with limited taxonomic understanding. Molecular characterization and phylogenetic analysis of F. jacksoni were carried out to evaluate its suggested basal position in the Fasciolidae. Adult worms were collected during post-mortem of elephants, and eggs were collected from living elephants in National parks across Sri Lanka. Using the mitochondrial genes nicotinamide dehydrogenase subunit 1 (nad1) and cytochrome oxidase subunit 1 (cox1), and a partial 28S ribosomal DNA (28S rDNA), DNA sequences were generated from the F. jacksoni adult and egg material. Maximum likelihood (ML) phylogenetic analyses did not resolve F. jacksoni to be basal to the Fasciolidae. Furthermore, the ML analyses showed that the genus Fasciola was not monophyletic and that F. jacksoni was a sister species to the deer liver fluke Fascioloides magna. A clear framework is required to determine the taxonomic status of F. jacksoni and this current study provides the first detailed application of molecular techniques from multiple hosts across Sri Lanka with the production of reference DNA sequences for this important parasite.
Subject(s)
Elephants/parasitology , Fasciola/classification , Fasciola/genetics , Fascioliasis/veterinary , Phylogeny , Animals , Cluster Analysis , DNA, Helminth/chemistry , DNA, Helminth/genetics , DNA, Mitochondrial/chemistry , DNA, Mitochondrial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Electron Transport Complex IV/genetics , Fasciola/isolation & purification , Fascioliasis/parasitology , NADH Dehydrogenase/genetics , RNA, Ribosomal, 28S/genetics , Sequence Analysis, DNA , Sri LankaABSTRACT
The present work provides a detailed morphological and molecular description of Anoplocephala manubriata in elephants. Adult worms were recovered during an autopsy of a wild elephant in Elephant Transit Home, Udawalawe, Sri Lanka. Necropsy findings revealed a severe cestode infection in the small intestine. These tapeworms were tightly attached to the intestinal mucosae, resulted in hyperemic thickened intestinal mucosae, variable size irregular well-demarcated multifocal ulcerative regions sometimes covered with necrotic membranes and variable size, diffuse, well-demarcated raised nodular masses were evident in the small intestine. The article provides an account of the biology of A. manubriata and a comparative analysis of the morphology and morphometrics of Anoplocephala species that occur in different hosts. Phylogenetic analysis of the second internal transcribed spacer region (ITS-2), a portion of the 28S region and cytochrome oxidase subunit 1 (COX1) genes revealed that A. manubriata is closely associated with Anoplocephala species in horse in comparison to other Anoplocephalines. This study will enhance the current knowledge in taxonomy of elephant tapeworms and contribute to future phylogenetic studies.
