Nematodirus of Domestic Sheep, Ovis aries, in the United States with a Key to the Species

Becklund, Willard W.; Walker, Martha

doi:10.2307/3276769

Cited by 12 publications

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“…Adult worms from each host were washed separately in physiological saline, fixed in 70% (v/v) ethanol and stored at -20°C until further study. Nematodirus species were firstly identified morphologically according to characteristics of the spicule tips and copulatory bursae and distribution of bosses on the internal surfaces of the bursae [5,8]. For each species, individual males were identified on the basis of bursal form, number of cuticular ridges and spicule morphology [25].…”

Section: Methodsmentioning

confidence: 99%

“…are among the most common nematodes of ruminants and more than 45 species have been described in the genus Nematodirus Ransom, 1907 [1,2]. Of these, Nematodirus oiratianus and N. spathiger are widely distributed as highly prevalent gastrointestinal nematodes, mainly inhabiting the small intestines of sheep and goats [3-5]. Although mild, or no symptoms are usually presented during Nematodirus infection in adult ruminants, growth retardation and emaciation of the growing host during infection may result in economic losses.…”

Section: Introductionmentioning

confidence: 99%

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Characterization of the complete mitochondrial genomes of Nematodirus oiratianus and Nematodirus spathiger of small ruminants

Zhao

Jia

Cheng

et al. 2014

Parasites & Vectors

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BackgroundNematodirus spp. are among the most common nematodes of ruminants worldwide. N. oiratianus and N. spathiger are distributed worldwide as highly prevalent gastrointestinal nematodes, which cause emerging health problems and economic losses. Accurate identification of Nematodirus species is essential to develop effective control strategies for Nematodirus infection in ruminants. Mitochondrial DNA (mtDNA) could provide powerful genetic markers for identifying these closely related species and resolving phylogenetic relationships at different taxonomic levels.MethodsIn the present study, the complete mitochondrial (mt) genomes of N. oiratianus and N. spathiger from small ruminants in China were obtained using Long-range PCR and sequencing.ResultsThe complete mt genomes of N. oiratianus and N. spathiger were 13,765 bp and 13,519 bp in length, respectively. Both mt genomes were circular and consisted of 36 genes, including 12 genes encoding proteins, 2 genes encoding rRNA, and 22 genes encoding tRNA. Phylogenetic analyses based on the concatenated amino acid sequence data of all 12 protein-coding genes by Bayesian inference (BI), Maximum likelihood (ML) and Maximum parsimony (MP) showed that the two Nematodirus species (Molineidae) were closely related to Dictyocaulidae.ConclusionsThe availability of the complete mtDNA sequences of N. oiratianus and N. spathiger not only provides new mtDNA sources for a better understanding of nematode mt genomics and phylogeny, but also provides novel and useful genetic markers for studying diagnosis, population genetics and molecular epidemiology of Nematodirus spp. in small ruminants.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Characterization of the complete mitochondrial genomes of Nematodirus oiratianus and Nematodirus spathiger of small ruminants

Zhao

Jia

Cheng

et al. 2014

Parasites & Vectors

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“…Generally, the Nematodirus sp. parasites have been identified by methods based on morphological characters of adult males such as the spicule tips, copulatory bursae and the distribution of bosses on the inside surface of the copulatory bursa (Becklund & Walker, 1967). Lichtenfels and Pilitt (1983) created a key to distinguish between females and males of the different species of the Nematodirus genus according to cuticular ridge patterns.…”

Section: Resultsmentioning

confidence: 99%

“…The guanaco population extends from Peru at 8 ºS to the Isla Navarino (archipelago of Tierra del Fuego, Chile) at 55 ºS (Wheeler, 1995). Nowadays, guanacos occupy a 40 % of the original area that they inhabited at pre-Hispanic times (Franklin et al, 1997), with about 840,000 individuals in all (González et al, 2006), from which 400,000 inhabit in Patagonia (Amaya et al, 2001). Parasites act as density-dependent factors regulating host population sizes (Anderson & May, 1979), particularly the wild species population (Tompkins & Begon, 1999).…”

Section: Introductionmentioning

confidence: 99%

Molecular identification of Nematodirus spathiger (Nematoda: Molineidae) in Lama guanicoe from Patagonia, Argentina

Petrigh

Fugassa

2014

Helminthologia

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79 SummaryThe guanaco (Lama guanicoe) is the major inhabitant and the largest wild artiodactyl in Patagonia. The introduction of invasive species into its ecological niche poses ecological risks, since invasive species may introduce harmful parasites to this native species. In this work, filariform larvae of the Nematodirus genus were found in feces of guanacos from the Perito Moreno National Park in Argentina. All species were characterized according to morphological features and molecular analyses using ribosomal DNA (rDNA). For the molecular analysis, rDNA fragments were amplified by PCR and then sequenced. The results of the BLASTN comparison threw a 99 % of identity with Nematodirus spathiger and 97 % with N. helvetianus, suggesting that N. spathiger is the infecting parasite. Nematodirus spathiger together with N. filicollis and N. battus causes diarrhea and deaths in sheep and, in some cases, in South American camelids. The availability of more accurate diagnostic methods such as PCR could improve the control measures for gastrointestinal helminthiasis.

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“…Traditional approaches to identify Nematodirus spp. have focused mainly on morphological characteristics of male worms, especially the tips of spicules and the copulatory bursa, including the distribution of bosses on the inner surface of the bursa (Becklund & Walker, 1967a, b; Stringfellow, 1968). In North America, six Nematodirus species, namely N. filicollis , N. davtiani , N. helvetianus , N. oiratianus interruptus ssp.…”

Section: Introductionmentioning

confidence: 99%

Molecular approaches to differentiate three species of Nematodirus in sheep and goats from China based on internal transcribed spacer rDNA sequences

et al. 2013

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Internal transcribed spacer (ITS) rDNA sequences of three Nematodirus species from naturally infected goats or sheep in two endemic provinces of China were analysed to establish an effective molecular approach to differentiate Nematodirus species in small ruminants. The respective intra-specific genetic variations in ITS1 and ITS2 rDNA regions were 0.3-1.8% and 0-0.4% in N. spathiger, 0-6.5% and 0-5.4% in N. helvetianus, and 0-4.4% and 0-6.1% in N. oiratianus from China. The respective intra-specific variations of ITS1 and ITS2 were 1.8-4.4% and 1.6-6.1% between N. oiratianus isolates from China and Iran, 5.7-7.1% and 6.3-8.3% between N. helvetianus samples from China and America. For N. spathiger, compared with samples from China, sequence differences in ITS1 rDNA were 0.3-2.4% in isolates from America, 0.3-2.9% in New Zealand and 2.1-2.4% in Australia. Genetic variations in ITS2 rDNA of N. spathiger were 0-0.4% between samples from China and America, and 0-0.8% between samples from China and New Zealand. Using mutation sites, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and specific PCR techniques were developed to differentiate these three Nematodirus species. The specific PCR assay allowed the accurate identification of N. oiratianus from other common nematodes with a sensitivity of 0.69 pg and further examination of Nematodirus samples demonstrated the reliability of these two molecular methods.

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Nematodirus of Domestic Sheep, Ovis aries, in the United States with a Key to the Species

Cited by 12 publications

References 0 publications

Characterization of the complete mitochondrial genomes of Nematodirus oiratianus and Nematodirus spathiger of small ruminants

Characterization of the complete mitochondrial genomes of Nematodirus oiratianus and Nematodirus spathiger of small ruminants

Molecular identification of Nematodirus spathiger (Nematoda: Molineidae) in Lama guanicoe from Patagonia, Argentina

Molecular approaches to differentiate three species of Nematodirus in sheep and goats from China based on internal transcribed spacer rDNA sequences

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