The efficacy of anthelmintic treatment on the parasite abundance of free-ranging snowshoe hares

1996 ◽  
Vol 74 (9) ◽  
pp. 1604-1611 ◽  
Author(s):  
Dennis L. Murray ◽  
Lloyd B. Keith ◽  
John R. Cary

We examined the efficacy of an anthelmintic agent (ivermectin, Merck–Agvet) on the parasitic nematodes of free-ranging snowshoe hares (Lepus americanus) during 27 months in southern Manitoba. Marked hares on six 25-ha sites were injected bimonthly with ivermectin (treatment, n = 134) or propylene glycol (control; n = 149) and carcasses were necropsied to determine prevalence and intensity of Obeliscoides cuniculi, Nematodirus triangularis, Trichuris leporis, Dirofilaria scapiceps, and Protostrongylus boughtoni. We supplemented the control sample with hares (n = 175) captured off the study sites and not given propylene glycol. Mean prevalence (percentage of hosts infected) and intensity (number of parasites among infected hosts) of each nematode species decreased after treatment and were 35 – 85% lower than controls after 20–40 days. Treatment significantly reduced prevalence of D. scapiceps and P. boughtoni for about 50 days and of O. cuniculi and N. triangularis for longer periods. Overall intensity of O. cuniculi, N. triangularis, and P. boughtoni was significantly lower in treated than in control hares, and intensity of D. scapiceps was marginally (P < 0.10) lower for 50 days post treatment. Total reductions in nematode abundance (prevalence × intensity) ranged from 29 to 88% among the five species. Neither prevalence nor intensity of ticks (Haemaphysalis leporispalustris) was reduced following treatment. We conclude that ivermectin is effective at controlling nematodes in snowshoe hares but that its efficacy is variable among species. We use our results as a basis for discussing the applicability of anthelmintics to the conservation and management of free-ranging wild mammals.

2007 ◽  
Vol 85 (6) ◽  
pp. 679-685 ◽  
Author(s):  
A.J. Wirsing ◽  
D.L. Murray

Field-based food supplementation experiments can determine whether populations are limited by natural food availability. However, they may yield spurious results if added food is hoarded by dominants, exploited by immigrants, or delivered ineffectively. Surprisingly, population-level approaches accounting for these potential sources of bias have not been established. We explored responses of free-ranging snowshoe hares ( Lepus americanus Erxleben, 1777) to food supplementation by contrasting per capita browsing rates on three study sites with added food with those on three control sites during two winters. Food augmentation reduced foraging pressure by hares; this reduction was significant when browse species of high dietary importance were considered. By implication, hares on manipulated sites switched from favored natural foods to supplemental food, meaning that the extra food found its mark and was not heavily exploited by immigrants or hoarded by dominants. Demographic responses to food addition were not detected on the manipulated sites, indicating that the study population was not food limited. Given the success with which we detected the signal of supplementation and eliminated potential confounding factors, we suggest that future studies using food addition in the context of herbivore population dynamics would benefit from a more mechanistic approach; this may involve measurement of browsing rates on manipulated and control sites.


2020 ◽  
Vol 12 (3) ◽  
pp. 15359-15363
Author(s):  
Sourabh Ranjan Hota ◽  
Sonali Sahoo ◽  
Manojita Dash ◽  
Avishek Pahari ◽  
Bijayendranath Mohanty ◽  
...  

Gastrointestinal helminths are ubiquitous in both domestic and wild animals. Infections are often sub-clinical except in circumstances of destabilization of host-parasite equilibrium by innate or environmental factors. The present case deals with microscopic and molecular diagnosis of Murshidia linstowi recovered from an elephant. A post-mortem examination of a free-ranging juvenile male elephant calf that had died of electrocution in Athagarh Wildlife Division revealed the presence of slender, whitish nematodes in the stomach. No gross lesions were noticed either in the site of predilection or any other internal organs. The average length of the parasites was 3.8cm.  These parasites were collected for further gross as well as microscopic examination following routine parasitological techniques. Temporary mounts prepared after cleaning the nematodes in lactophenol were observed under a microscope. Morphological features such as a well-developed mouth collar, large and globular buccal capsule with fine tubercles, cone shaped oesophageal funnel, short bursa having indistinctly divided lobes and closely apposed ventral rays and stout spicules with club shaped tips bent dorsally corroborated with that of M.linstowi (male). Amplification of the rDNA from the internal transcribed spacer (ITS) region using universal nematode primers NC2 and NC5 revealed a product size of 870bp. The PCR product was subjected to sequencing followed by NCBI-BLAST which revealed 98% homology with M. linstowi. A phylogenetic study showed a maximum similarity with M.linstowi recovered from elephants in Kenya. This particular nematode species belonging to the family Strongylidae and sub-family Cyathostominae appears to be the first documented report in India.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Khalid M. Mohammedsalih ◽  
Jürgen Krücken ◽  
Ahmed Bashar ◽  
Fathel-Rahman Juma ◽  
Abdalhakaim A. H. Abdalmalaik ◽  
...  

Abstract Background Benzimidazole (BZ) anthelmintics are widely used to control infections with parasitic nematodes, but BZ resistance is an emerging threat among several nematode species infecting humans and animals. In Sudan, BZ-resistant Haemonchus contortus populations were recently reported in goats in South Darfur State. The objective of this study was to collect data regarding the situation of BZ resistance in cattle parasitic nematodes in South Darfur using phenotypic and molecular approaches, besides providing some epidemiological data on nematodes in cattle. Methods The faecal egg count reduction test and the egg hatch test (EHT) were used to evaluate benzimidazole efficacy in cattle nematodes in five South Darfur study areas: Beleil, Kass, Nyala, Rehed Al-Birdi and Tulus. Genomic DNA was extracted from pools of third-stage larvae (L3) (n = 40) during trials, before and after treatment, and pools of adult male Haemonchus spp. (n = 18) from abattoirs. The polymorphisms F167Y, E198A and F200Y in isotype 1 β-tubulin genes of H. contortus and H. placei were analysed using Sanger and pyrosequencing. Results Prevalence of gastro-intestinal helminths in cattle was 71% (313/443). Reduced albendazole faecal egg count reduction efficacy was detected in three study areas: Nyala (93.7%), Rehed Al-Birdi (89.7%) and Tulus (88.2%). In the EHT, EC50 values of these study areas ranged between 0.032 and 0.037 µg/ml thiabendazole. Genus-specific PCRs detected the genera Haemonchus, Trichostrongylus and Cooperia in L3 samples collected after albendazole treatment. Sanger sequencing followed by pyrosequencing assays did not detect elevated frequencies of known BZ resistance-associated alleles in codon F167Y, E198A and F200Y in isotype 1 β-tubulin gene of H. placei (≤ 11.38%). However, polymorphisms were detected in H. contortus and in samples with mixed infections with H. contortus and H. placei at codon 198, including E198L (16/58), E198V (2/58) and potentially E198Stop (1/58). All pooled L3 samples post-albendazole treatment (n = 13) were identified as H. contortus with an E198L substitution at codon 198. Conclusions To the knowledge of the authors, this is the first report of reduced albendazole efficacy in cattle in Sudan and is the first study describing an E198L substitution in phenotypically BZ-resistant nematodes collected from cattle.


Nematology ◽  
2016 ◽  
Vol 18 (8) ◽  
pp. 879-903 ◽  
Author(s):  
Thomas O. Powers ◽  
Peter Mullin ◽  
Rebecca Higgins ◽  
Timothy Harris ◽  
Kirsten S. Powers

A new species of Mesocriconema and a unique assemblage of plant-parasitic nematodes was discovered in a heath bald atop Brushy Mountain in Great Smoky Mountains National Park. Mesocriconema ericaceum n. sp., a species with males, superficially resembles M. xenoplax. DNA barcoding with the mitochondrial COI gene provided evidence of the new species as a distinct lineage. SEM revealed significant variability in arrangement of labial submedian lobes, plates, and anterior and posterior annuli. Three other nematodes in the family Criconematidae were characterised from the heath bald. Ogma seymouri, when analysed by statistical parsimony, established connections with isolates from north-eastern Atlantic coastal and north-western Pacific coastal wet forests. Criconema loofi has a southern Gulf Coast distribution associated with boggy soils. Criconema cf. acriculum is known from northern coastal forests of California. Understanding linkages between these species and their distribution may lead to the broader development of a terrestrial soil nematode biogeography.


Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 825
Author(s):  
Tao Wang ◽  
Robin Gasser

Parasitic nematodes impose a significant public health burden, and cause major economic losses to agriculture worldwide. Due to the widespread of anthelmintic resistance and lack of effective vaccines for most nematode species, there is an urgent need to discover novel therapeutic and vaccine targets, informed through an understanding of host–parasite interactions. Proteomics, underpinned by genomics, enables the global characterisation proteins expressed in a particular cell type, tissue and organism, and provides a key to insights at the host–parasite interface using advanced high-throughput mass spectrometry-based proteomic technologies. Here, we (i) review current mass-spectrometry-based proteomic methods, with an emphasis on a high-throughput ‘bottom-up’ approach; (ii) summarise recent progress in the proteomics of parasitic nematodes of animals, with a focus on molecules inferred to be involved in host–parasite interactions; and (iii) discuss future research directions that could enhance our knowledge and understanding of the molecular interplay between nematodes and host animals, in order to work toward new, improved methods for the treatment, diagnosis and control of nematodiases.


Nematology ◽  
2021 ◽  
pp. 1-9
Author(s):  
Hung X. Bui ◽  
Johan A. Desaeger

Summary Cover crops can be a useful tool for managing plant-parasitic nematodes provided they are poor or non-hosts for the target nematode species. A glasshouse experiment was done to determine the host status of four common cover crops in Florida, sunn hemp, cowpea, sorghum sudangrass and sunflower, to pure populations of four common tropical root-knot nematode (RKN) species Meloidogyne javanica (Mj), M. incognita (Mi), M. enterolobii (Me) and M. arenaria (Ma). Tomato was included as a susceptible control. Eight weeks after nematode inoculation (WAI), tomato showed the highest root gall damage for all tested RKN species, with gall indices (GI) between 7 (Ma) and 8.5 (Me) and reproduction factor (RF) ranging from 20 (Ma) to 50 (Mj). No visible root galls were observed for any of the RKN species on sunn hemp and sorghum sudangrass at 8 WAI. However, Mj and Mi were able to reproduce slightly on sorghum sudangrass (RF = 0.02 and 0.79, respectively). Sunflower and cowpea were infected by all four tested RKN species, but host suitability varied. Sunflower root galling ranged from 1.1 (Me) to 4.5 (Mj) and RF = 3.2 (Me) to 28.7 (Mj), while cowpea root galling ranged from 0.6 (Mi) to 5.1 (Me) and RF = 0.8 (Mi) to 67.3 (Mj). Sunn hemp and, to a lesser extent, sorghum sudangrass were poor hosts to all four tested RKN species. Sunflower was a good host to all RKN species, but root gall damage and RF were lowest for Me. Cowpea was a good host to Mj, Me and Ma, but a poor host to Mi. Our results confirm and stress the importance of RKN species identification when selecting cover crops as an RKN management strategy.


Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 897 ◽  
Author(s):  
Beatriz Hernández-Carlos ◽  
Marcela Gamboa-Angulo

Plant metabolites have been used for many years to control pests in animals and to protect crops. Here, we reviewed the available literature, looking for the species of Mexican flora for which extracts and metabolites have shown activity against pest insects and parasitic nematodes of agricultural importance, as well as against nematodes that parasitize domestic cattle. From 1996 to 2018, the search for novel and eco-friendly biopesticides has resulted in the identification of 114 species belonging to 36 botanical families of Mexican plants with reported biological effects on 20 insect species and seven nematode species. Most plant species with detected pesticide properties belong to the families Asteraceae, Fabaceae, and Lamiaceae. Eighty-six metabolites have been identified as pesticidal active principles, and most have been terpenoids. Therefore, the continuation and intensification of this area of research is very important to contribute to the generation of new products that will provide alternatives to conventional pesticide agents. In addition, future studies will contribute to the recognition and dissemination of the importance of propagating plant species for their conservation and sustainable use.


Author(s):  
Pavlína Šenoldová ◽  
Jiří Rotrekl

This paper compares efficiency of preparations based on a parasitic nematode species Phasmarhabditis hermaphrodita with a molluscocide containing methiocarb as an effective substance. Parasitic nematodes by the family Agriolimacidae showed a significantly better effect on mortality and reduction of the percentage of damaged plants than the methiocarb-based preparation. Under laboratory and field conditions, the efficiency of parasitic nematodes on the family Agriolimacidae ranged from 84% to 94% and from 81% to 94%, resp., while the percentages of damaged plants were minimal in both cases. The corresponding effects of the methiocarb-based molluscocide were only 35% and 21%, resp. The effect of parasitic P. hermaphrodita nematodes on members of the snail family Arionidae was not demonstrated both under laboratory and field conditons and the mortality was up to 6% with a total defoliation of plants. Under laboratory and field conditions, the mortality of slugs from the genus Arion after the application of methiocarb-based preparation was 53% and 38%, resp. However, the damage of plants was significant and it reached nearly 67% and 60% under laboratory and field conditions, resp.


ZooKeys ◽  
2015 ◽  
Vol 489 ◽  
pp. 1-13 ◽  
Author(s):  
Gezahegne Damessa ◽  
Wim Bert ◽  
Frieda Decraemer

A total of six soil samples were collected around rhizosphere of citrus plants during 2010 from Melkassa Agricultural Research Center experimental station, Ethiopia. From these samples two most important ecto-plant parasitic nematodes of the genus Xiphinema were found and analysed. The genus Xiphinema is a large group of the phylum nematoda which constitutes more than 260 species. They are polyphagous root- ectoparasites of many crop plants and some species of this genus cause damage by direct feeding on root tips and transmit nepoviruses. The delimitation and discrimination of two species in the genus is presented, described herein as Xiphinemaelongatum and Xiphinemapachtaicum. Morphological and morphometric data were done using light microscopy and results of both species were fit within the previously described nematode species of Xiphinemaelongatum and Xiphinemapachtaicum. 18S rDNA were analysed using Bayesian inference (BI) method to reconstruct phylogenetic relationships of the studied Xiphinema sp. (KP407872Xiphinemaelongatum and KP407873Xiphinemapachtaicum) with other Xiphinema species. The 18S rDNA sequence of Xiphinemapachtaicum was alike to previously described species from the GenBank but Xiphinemaelongatum exhibited very small levels of nucleotides differences (0.4%) which might be possible intra-specific divergence. Though this region of rDNA has less resolution on complex species, its combination with morphological and morphometric analyses, suggests these species as Xiphinemaelongatum and Xiphinemapachtaicum with the GenBank accession number of KP407872 and KP407873, respectively. Short notes, morphological measurements, illustrations, and molecular data are given to these species. These species are reported for the first time from Ethiopia and it provides new geographical information of these organisms.


Nematology ◽  
2001 ◽  
Vol 3 (2) ◽  
pp. 129-139 ◽  
Author(s):  
Jaap Bakker ◽  
Fred Gommers ◽  
Geert Smant ◽  
Pierre Abad ◽  
Marie-Noëlle Rosso ◽  
...  

AbstractExpressed sequence tags (EST) have been widely used to assist in gene discovery in various organisms (e.g., Arabidopsis thaliana, Caenorhabditis elegans, Mus musculus, and Homo sapiens). In this paper we describe an EST project, which aims to investigate gene expression in Meloidogyne incognita at the onset of parasitism. Approximately 1000 5′-end sequence tags were produced from a cDNA library made of freshly hatched preparasitic second stage juveniles (J2). The EST were identified in the primary transformants of the cDNA library, and assigned to nine different functional groups, including (candidate) parasitism genes. A large fraction of the EST (45%) did not have a putative homologue in public databases. Sixty five percent of the EST that could be clustered into a functional group had putative homologues in other nematode species. EST were found for virtually all parasitism related genes that have been cloned from M. incognita to date. In addition, several novel genes were tagged, including a xylanase and a chitinase gene. The efficiency of EST projects, which produce sequence data for thousands of genes in months time without any difficult pre-selections of mRNA pools, makes random sequencing cDNA libraries a superior method to identify candidates for parasitism related genes in plant-parasitic nematodes. The sequences in this paper are retrievable from Genbank with the accession numbers BE191640 to BE191741, BE217592 to BE217720, BE225324 to BE225598, BE238852 to BE239221, and BE240829 to BE240865.


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