A study of free-living nematode, Panagrolaimus (Nematoda: Rhabditida) using 18S rDNA from South Africa

2021 ◽  
Vol 22 (4) ◽  
Nematology ◽  
2021 ◽  
pp. 1-18
Author(s):  
Ebrahim Shokoohi ◽  
Joaquín Abolafia

Summary Butlerius butleri was isolated during a survey on free-living soil nematodes from South Africa. The South African population of B. butleri is characterised by having a large stoma divided into two chambers and bearing a thorn-like dorsal tooth, spicules 44 (41-49) μm long, gubernaculum 29 (28-30) μm long, three pairs of precloacal papillae and five pairs of postcloacal papillae, and a filiform tail 280 (204-332) μm long in females, 310 (256-356) μm long in males. The SEM observation showed the cheilostom is divided into six conical plates 2.1-2.3 μm long. Nblast of 18S rDNA revealed 99% similarity and 6-7 bp differences with the B. butleri (KP453998) from Iran. Molecular analysis of B. butleri based on the sequence of the 18S and 28S rDNA placed it together with Butlerius and close to Pseudodiplogasteroides and Diplogasteroides. This species showed predatory and cannibalistic behaviours, feeding on other B. butleri in the substrate. SEM photographs of the species are presented for the first time.


Acarina ◽  
2020 ◽  
Vol 28 (1) ◽  
pp. 55-64
Author(s):  
Omid Joharchi ◽  
Elizabeth Hugo-Coetzee ◽  
Sergey G. Ermilov ◽  
Alexander A. Khaustov

Hypoaspisella spiculifer comb. n. is redescribed on the basis of adult females, collected from soil in South Africa. Hypoaspisella spiculifer fits well with the current concept of the genus Hypoaspisella Bernhard. The chelicerae of this species are similar to those of free-living mites, suggesting that it may be a predator of small soil invertebrates.


Parasitology ◽  
2014 ◽  
Vol 141 (9) ◽  
pp. 1203-1215 ◽  
Author(s):  
VICTORIA GILLAN ◽  
EILEEN DEVANEY

SUMMARYNematodes are amongst the most successful and abundant organisms on the planet with approximately 30 000 species described, although the actual number of species is estimated to be one million or more. Despite sharing a relatively simple and invariant body plan, there is considerable diversity within the phylum. Nematodes have evolved to colonize most ecological niches, and can be free-living or can parasitize plants or animals to the detriment of the host organism. In this review we consider the role of heat shock protein 90 (Hsp90) in the nematode life cycle. We describe studies on Hsp90 in the free-living nematode Caenorhabditis elegans and comparative work on the parasitic species Brugia pahangi, and consider whether a dependence upon Hsp90 can be exploited for the control of parasitic species.


Parasitology ◽  
2018 ◽  
Vol 146 (3) ◽  
pp. 314-320 ◽  
Author(s):  
Veeren M Chauhan ◽  
David I Pritchard

AbstractCaenorhabditis elegans is a free-living nematode that resides in soil and typically feeds on bacteria. We postulate that haematophagic C. elegans could provide a model to evaluate vaccine responses to intestinal proteins from hematophagous nematode parasites, such as Necator americanus. Human erythrocytes, fluorescently labelled with tetramethylrhodamine succinimidyl ester, demonstrated a stable bright emission and facilitated visualization of feeding events with fluorescent microscopy. C. elegans were observed feeding on erythrocytes and were shown to rupture red blood cells upon capture to release and ingest their contents. In addition, C. elegans survived equally on a diet of erythrocytes. There was no statistically significant difference in survival when compared with a diet of Escherichia coli OP50. The enzymes responsible for the digestion and detoxification of haem and haemoglobin, which are key components of the hookworm vaccine, were found in the C. elegans intestine. These findings support our postulate that free-living nematodes could provide a model for the assessment of neutralizing antibodies to current and future hematophagous parasite vaccine candidates.


2005 ◽  
Vol 21 (1) ◽  
pp. 329-332 ◽  
Author(s):  
Alexandre Fernandes ◽  
Luiz Fernando Ferreira ◽  
Marcelo Luiz Carvalho Gonçalves ◽  
Françoise Bouchet ◽  
Carlos Henrique Klein ◽  
...  

Parasite eggs found in organic remains collected from medieval structures in Raversijde (medieval name: Walraversijde), a village on the northern coast of Belgium, are discussed. The eggs were identified as Ascaris lumbricoides and Trichuris trichiura, both human parasites. Species identification allowed elucidating the origin of the organic sediments and the structures, in this case latrines used by humans. Capillaria sp. and free-living nematode larvae were also found in the latrine. Although neither parasite burden nor prevalence rates could be measured, the abundance of human intestinal parasite eggs indicated a high infection rate in the village residents, reflecting very poor sanitation.


2016 ◽  
Vol 283 (1835) ◽  
pp. 20160942 ◽  
Author(s):  
Jinshui Zheng ◽  
Donghai Peng ◽  
Ling Chen ◽  
Hualin Liu ◽  
Feng Chen ◽  
...  

Plant-parasitic nematodes were found in 4 of the 12 clades of phylum Nematoda. These nematodes in different clades may have originated independently from their free-living fungivorous ancestors. However, the exact evolutionary process of these parasites is unclear. Here, we sequenced the genome sequence of a migratory plant nematode, Ditylenchus destructor . We performed comparative genomics among the free-living nematode, Caenorhabditis elegans and all the plant nematodes with genome sequences available. We found that, compared with C. elegans , the core developmental control processes underwent heavy reduction, though most signal transduction pathways were conserved. We also found D. destructor contained more homologies of the key genes in the above processes than the other plant nematodes. We suggest that Ditylenchus spp. may be an intermediate evolutionary history stage from free-living nematodes that feed on fungi to obligate plant-parasitic nematodes. Based on the facts that D. destructor can feed on fungi and has a relatively short life cycle, and that it has similar features to both C. elegans and sedentary plant-parasitic nematodes from clade 12, we propose it as a new model to study the biology, biocontrol of plant nematodes and the interaction between nematodes and plants.


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