scholarly journals PARASITIC NEMATODE INFECTIONS OF ANURANS FROM A DERIVED SAVANNA BIOTOPE IN EDO STATE, NIGERIA

2021 ◽  
Vol 2 (2) ◽  
pp. 166-182
Author(s):  
H. J. Ozemoka ◽  
M. S. O. Aisien

As part of a broader study to increase the information of parasite infections of anurans from the savanna biotope, an investigation of the nematode parasites of anurans in Agbede, a location in the derived savanna of Edo State, Nigeria was undertaken from August 2007 to July 2008. Anurans were collected at night using the visual acoustic encounter survey (VAES) sampling method, dissected and examined for nematode infections. A total of 329 anurans belonging to sixteen taxa, were examined, of which 235 were infected with an overall prevalence of 71.43%. Seasonal prevalences were 85.63% for wet season and 52.48% for the dry season (p<0.05). Ten nematode species, namely: Amplicaecum africanum, Cosmocerca ornata, Oswaldocruzia hoeplii, Physaloptera sp., Rhabdias africanus, Rhabdias sp., Camallanus dimitrovi, an unidentified oxyurid nematode, Ophidascaris larva, and an unidentified nematode were recovered from the hosts examined. The most common nematode species was Amplicaecum africanum (31.31%), whereas the least common was an unidentified oxyurid nematode (0.30%).Physaloptera sp. is a new record for the anurans of the derived savanna.

2020 ◽  
Vol 41 (2) ◽  
Author(s):  
H.J Ozemoka ◽  
M.O.S Aisien

An investigation of the digenetic trematodes of anurans from Agbede, a location in the derived savanna biotope in Edo state,Nigeria was conducted from August, 2007 to July, 2008. Anuran hosts examined included Sclerophrys maculata, S.regularis, Ptychadena pumilio, P. bibroni, P. oxyrhynchus, Hoplobatrachus occipitalis and Hylarana galamensis. Theanurans were collected using the Visual Acoustic Encounter Survey (VAES) method, dissected and examined for trematodeinfections. A total of 267 anurans were examined of which 33 were infected with an overall prevalence of 12.36%. Seasonalprevalence was 14.88% for the wet season and 8.08% for dry season. The difference in prevalence values was not statisticallysignificant (p >0.05). Four digenetic trematodes, namely, Mesocoelium monodi, an unidentified Mesocoelium sp.,Haematoloechus exoterorchis and an unidentified Haematoloechus sp. Haematoloechus exoterorchis was recovered from H.occipitalis while the unidentified Haematoloechus sp. infected H. occipitalis and Sclerophrys maculata. Mesocoeliummonodi infected only Sclerophrys maculata while the unidentified Mesocoelium sp. was a generalist, infecting five anuranhosts. Sclerophrys maculata is thus a new host record for the genus Haematoloechus in Nigeria. In conclusion, this studyrevealed a low trematode diversity in the anurans of the savanna-mosaic at Agbede. However, anurans from this locationharboured two new trematodes: an unidentified Mesocoelium sp and a Haematolechus sp. Sclerophrys maculata as a newhost record for the genus Haematoloechus in Nigeria. More specimens of the Haematoloechus sp. are needed for themorphological description and molecular characterization of the parasite, to establish its relationship with the cogener inH.occipitalis. Keywords: Derived savannah, Anurans, Digenetic trematodes, new host record


2021 ◽  
Author(s):  
Fiona M McKay ◽  
Ciaran J McCoy ◽  
Nikki J Marks ◽  
Aaron G Maule ◽  
Louise E Atkinson ◽  
...  

Nematode parasite infections cause disease in humans and animals and threaten global food security by reducing productivity in livestock and crop farming. The escalation of anthelmintic resistance in economically important nematode parasites underscores the need for the identification of novel drug targets in these worms. Nematode neuropeptide signalling is an attractive system for potential chemotherapeutic exploitation, with neuropeptide G-protein coupled receptors (NP-GPCRs) representing the leading target candidates therein. In order to successfully validate NP-GPCRs as targets for parasite control it is necessary to characterise their function and importance to nematode biology. This can be aided through identifying receptor activating ligand(s) in a process known as receptor deorphanisation. Such efforts first require the identification of all neuropeptide ligands within parasites. Here we comb the genomes of nine therapeutically relevant pathogenic nematode species to comprehensively characterise the nematode parasite neuropeptide-like protein (NLP) complements, and details the discovery of several previously unreported, yet conserved, neuropeptides and neuropeptide-encoding genes. We identify the neuropeptides that are most highly conserved in all parasites examined, and characterise their physiological activity on the reproductive musculature of the parasite, Ascaris suum. These data suggest conserved neuropeptide functions in both free living and parasitic nematodes, and support the potential for exploitation of the neuropeptide signalling system as an anthelmintic target.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Peter Halvarsson ◽  
Johan Höglund

Abstract Background A novel way to study the species composition and diversity of nematode parasites in livestock is to perform deep sequencing on composite samples containing a mixture of different species. Herein we describe for the first time the nematode community structures (nemabiomes) inhabiting Swedish sheep and how these are/were affected by host age and recent anthelmintic treatments. Methods A total of 158 fecal samples were collected (n = 35 in 2007 and n = 123 in 2013–2016) and cultured from groups of sheep on 61 commercial farms in the south-central part of the country where most animals are grazed. Among the samples, 2 × 44 (56%) were paired collections from the same groups pre- and post-treatment with anthelmintics such as macrocyclic lactones, benzimidazoles or levamisole. Samples were analyzed for their nemabiome using the PacBio platform followed by bioinformatic sequence analysis with SCATA. Species richness and diversity were calculated and analyzed in R. Results Nematode ITS2 sequences were found in all larval culture samples except two, even though the fecal egg counts were below the McMaster threshold in 20 samples. Sequencing yielded, on average, 1008 sequences per sample. In total, 16 operational taxonomical units (OTU), all with ≥ 98 % identity to sequences in the NCBI database, were recognized. The OTUs found represented nematode species of which ten are commonly associated with sheep. Multiple species were identified in all pre-anthelmintic treatment larval culture samples. No effects on nematode diversity were found in relation to host age. On the other hand, recent anthelmintic treatment lowered species richness, especially after use of ivermectin and albendazole. Interestingly, despite zero egg counts after use of levamisole, these samples still contained nematode DNA and especially H. contortus. Conclusions Our findings provide evidence that nemabiome analysis combined with diversity index analysis provides an objective methodology in the study of the efficacy of anthelmintic treatment as both high and low abundant species were detected.


Molecules ◽  
2022 ◽  
Vol 27 (1) ◽  
pp. 312
Author(s):  
Tina V. A. Hansen ◽  
Heinz Sager ◽  
Céline E. Toutain ◽  
Elise Courtot ◽  
Cédric Neveu ◽  
...  

Natural plant compounds, such as betaine, are described to have nematocidal properties. Betaine also acts as a neurotransmitter in the free-living model nematode Caenorhabditis elegans, where it is required for normal motility. Worm motility is mediated by nicotinic acetylcholine receptors (nAChRs), including subunits from the nematode-specific DEG-3 group. Not all types of nAChRs in this group are associated with motility, and one of these is the DEG-3/DES-2 channel from C. elegans, which is involved in nociception and possibly chemotaxis. Interestingly, the activity of DEG-3/DES-2 channel from the parasitic nematode of ruminants, Haemonchus contortus, is modulated by monepantel and its sulfone metabolite, which belong to the amino-acetonitrile derivative anthelmintic drug class. Here, our aim was to advance the pharmacological knowledge of the DEG-3/DES-2 channel from C. elegans by functionally expressing the DEG-3/DES-2 channel in Xenopus laevis oocytes and using two-electrode voltage-clamp electrophysiology. We found that the DEG-3/DES-2 channel was more sensitive to betaine than ACh and choline, but insensitive to monepantel and monepantel sulfone when used as direct agonists and as allosteric modulators in co-application with betaine. These findings provide important insight into the pharmacology of DEG-3/DES-2 from C. elegans and highlight the pharmacological differences between non-parasitic and parasitic nematode species.


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.


2021 ◽  
Vol 13 (1) ◽  
pp. 17601-17603
Author(s):  
H.U. Abhijit ◽  
Y.L. Krishnamurthy ◽  
K. Gopalakrishna Bhat

For the documentation of grasses in the central Western Ghats of Karnataka, we have conducted the extensive field surveys by using random sampling method from 2017 to 2020.  During this survey we have collected some grass specimens from the shola grassland, which forms the new distributional record of Trisetopsis aspera (Munro ex Thwaites) Roser & A. Wolk to the flora of central Western Ghats, Karnataka, India from the montane high- lands of Baba Budangiri hills of Chikkamagaluru District.


2017 ◽  
Vol 57 (Suppl.) ◽  
pp. 221-225 ◽  
Author(s):  
Zdeněk Faltýnek Fric ◽  
Michal Rindoš ◽  
Vladimír Hula

Eurema brigitta (Stoll, 1780) (Lepidoptera: Pieridae) is recorded for the first time from the Socotra Island (Yemen). The specimen represents either a wet season form of a subspecies originating from Africa or a form with its usual occurrence in Madagascar, Mascarenes, Aldabra and Comoros. The current number of butterfly species known for Socotra is now 27.


2013 ◽  
Vol 88 (3) ◽  
pp. 302-309 ◽  
Author(s):  
N. Pakdeenarong ◽  
P. Siribat ◽  
K. Chaisiri ◽  
B. Douangboupha ◽  
A. Ribas ◽  
...  

AbstractThe helminth communities of wild murid rodents were investigated in Luang Prabang and Champasak province, Lao PDR. Thirteen species of rodents (404 individuals) were infected by 19 species of parasites (2 trematode, 3 cestode, 14 nematode species). Four of the recorded helminth species (Echinostoma malayanum,Raillietinasp.,Hymenolepis diminutaandH. nana)are known to cause potential zoonotic helminthiases of medical importance in the South-East Asian region. Individual helminth infection was significantly higher in the wet season. Habitat significantly influenced individual helminth species richness and individual helminth abudance, with a decrease of individual helminth species richness and individual helminth abundance from forest habitat to agricultural and human settlement habitats. The reduction of helminth diversity and abundance is discussed in relation to the ongoing increase of human influence on habitats in Lao PDR.


Animals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1420
Author(s):  
Simon Allen ◽  
Carolyn Greig ◽  
Ben Rowson ◽  
Robin B. Gasser ◽  
Abdul Jabbar ◽  
...  

The Western European Hedgehog (Erinaceous europaeus) is a nocturnal animal that is in decline in much of Europe, but the monitoring of this species is subjective, prone to error, and an inadequate basis for estimating population trends. Here, we report the use of Crenosoma striatum, a parasitic nematode specific to hedgehogs as definitive hosts, to detect hedgehog presence in the natural environment. This is achieved through collecting and sampling the parasites within their intermediate hosts, gastropoda, a group much simpler to locate and sample in both urban and rural habitats. C. striatum and Crenosoma vulpis were collected post-mortem from the lungs of hedgehogs and foxes, respectively. Slugs were collected in two sessions, during spring and autumn, from Skomer Island (n = 21), which is known to be free of hedgehogs (and foxes); and Pennard, Swansea (n = 42), known to have a healthy hedgehog population. The second internal transcribed spacer of parasite ribosomal DNA was used to develop a highly specific, novel, PCR based multiplex assay. Crenosoma striatum was found only at the site known to be inhabited by hedgehogs, at an average prevalence in gastropods of 10% in spring and autumn. The molecular test was highly specific: One mollusc was positive for both C. striatum and C. vulpis, and differentiation between the two nematode species was clear. This study demonstrates proof of principle for using detection of specific parasite DNA in easily sampled intermediate hosts to confirm the presence of an elusive nocturnal definitive host species. The approach has great potential as an adaptable, objective tool to supplement and support existing ecological survey methods.


Diversity ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 265
Author(s):  
Ulrich Sinsch ◽  
J. Maximilian Dehling ◽  
Patrick Scheid ◽  
Carsten Balczun

The diversity of nematodes infecting amphibians is understudied in tropical Africa and unknown in Rwanda. Diversity assessment is hampered by the fact that species descriptions refer mostly to morphological features that are unlinked to DNA sequences of marker genes available in public databases. In this paper, we explore the abundance and diversity of parasitic nematodes in reed frogs Hyperolius kivuensis (n = 115), H. parallelus (n = 45) and H. viridiflavus (n = 100) collected in Rwanda. Five nematode species were identified morphologically as Orneoascaris chrysanthemoides, O. schoutedeni, Gendria leberrei, Aplectana chamaeleonis and Rhabdias collaris. Corresponding DNA sequences of 18S and COI genes were determined and subsequently deposited in GenBank. Aplectana chamaeleonis showed the highest prevalence (8.7%), but O. chrysanthemoides the highest mean intensity of infection (6.0) and largest number (24) of individuals in H. kivuensis. To the best of our knowledge, all amphibian hosts are new records for these nematode species, which are known to infect a wide range of amphibian and reptile species. Our findings suggest that nematode diversity is probably lower than previously assumed due to low host specificity. As morphological species identification is often challenging, our data facilitate molecular identification of adult and specifically larval nematodes found in amphibians of Sub-Saharan Africa.


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