Search results for "NEMATODE"
showing 10 items of 94 documents
Aging parasites produce offspring with poor fitness prospects.
2017
Senescing individuals have poor survival prospects and low fecundity. They can also produce offspring with reduced survival and reproductive success. We tested the effect of parental age on the performance of descendants in the nematode Heligmosomoides polygyrus , an intestinal parasite of rodents. We found that offspring of senescing worms had reduced within-host survival and reduced egg shedding over the first month post-infection compared with offspring produced by young parents. These results suggest that declining offspring quality is a component of senescence in parasitic nematodes and might have evolutionary consequences for the optimal schedule of age-dependent investment into repr…
Role of Crassicauda sp. in natural mortality of pantropical spotted dolphins Stenella attenuata: a reassesment
2014
Evaluating the effect of parasites on population size is essential for designing management and conservation plans of wild animal populations. Although knowledge in this area is scarce in cetaceans, current evidence suggests that species of the nematode genus Crassicauda may play an important regulatory role in some populations. In the present study, a semiparametric regression technique is applied to a previously published dataset to re-examine the role of Crassicauda sp. in natural mortality of pantropical spotted dolphins Stenella attenuata. The resulting model indicated parasite-induced mortality at ages between 6.5 and 9 years and at roughly 12 years. The maximum mortality estimates ob…
Response Mechanisms of Invertebrates to Bacillus thuringiensis and Its Pesticidal Proteins
2021
SUMMARY Extensive use of chemical insecticides adversely affects both environment and human health. One of the most popular biological pest control alternatives is bioinsecticides based on Bacillus thuringiensis. This entomopathogenic bacterium produces different protein types which are toxic to several insect, mite, and nematode species. Currently, insecticidal proteins belonging to the Cry and Vip3 groups are widely used to control insect pests both in formulated sprays and in transgenic crops. However, the benefits of B. thuringiensis-based products are threatened by insect resistance evolution. Numerous studies have highlighted that mutations in genes coding for surrogate receptors are …
Gastrointestinal helminths of cuvier’s beaked whales, ziphius cavirostris, From the Western Mediterranean
2004
We examined the gastrointestinal helminth fauna of 2 Cuvier's beaked whales, Ziphius cavirostris, stranded on the Spanish Mediterranean coast. Information regarding intestinal parasites of this species is provided for the first time. Six helminth taxa were identified. Thirty type II larvae of the nematode Anisakis sp. were found in the stomach and the intestine of both hosts; 2 type I larvae of Anisakis sp. were found in the intestine of 1 host. One juvenile of the acanthocephalan Bolbosoma vasculosum was found in the intestine; the metacestode Scolex pleuronectis was found mainly in the terminal colon and the anal crypts of both hosts; adult cestodes of Tetrabothrius sp., which may represe…
Effect of plant sterol and galactooligosaccharides enriched beverages on oxidative stress and longevity in Caenorhabditis elegans
2020
Abstract This study evaluates the impact of two plant sterol (PS) enriched fruit beverages (0.6 g /100 ml), without (MfB) or with GOS (MfB-G) (1.2 g/100 ml) on the resistance against oxidative stress induced by non-conventional (cholesterol oxidation products (COPs)) and conventional (H2O2) oxidant compounds, as well as their impact on C. elegans longevity. Nematodes fed with both beverages (0.005–0.25%, v/v) showed similar improved oxidative stress resistance against COPs and H2O2. This effect was dependent on daf-16 transcription factor, although GOS showed an additional beneficial effect independent to daf-16. In addition, both beverages extended nematode lifespan, independently of the p…
OBSERVATIONS ON THE BIOLOGY OF A PREDATORY NEMATODE BELONGING TO DIPLOGASTERIDAE
2011
The use of predatory nematodes as biological control agents of phytoparasitic nematodes has been re-evaluated only recently. To be effective, predatory nematodes should be easy to grow, cheap, and available on a commercial scale. In addition, they must show a reproductive rate sufficient to sustain a high population density and a significant longevity and stability for storage. The predators are not phytopathogenic nematodes, and among the positive outcomes of their introduction are remarkable their environment compatibility and safety for other non-target organisms, as well as the ability to search for prey. These features are present in Diplogasteridae. Their adaptability enables them to …
Biodiversity of nematofauna associated with the rice field agro-ecosystem in north Italy
2008
This research is intended to give an idea on the soil biodiversity associated with the rice field agro-ecosystem. The research was carried out in two areas of North Italy where Oryza sativa is a traditional crop. The nematodes were extracted from soil samples and from the rhizosphere of rice plants. The nematode community was investigated for the genus composition, trophic structure and biodiversity. 22 families and 45 different genera were recorded. The dominant trophic group was the bacteriophagous with the genus Rhabditis. Other important genera were Pratylenchus, Helicotylenchus and Acrobeloides. Phytophagous represent in almost all fields not more than the 20% of the total nematodes. I…
Investment in multiple defences protects a nematode-bacterium symbiosis from predation
2017
The act of predation often comprises multiple sequential steps whereby prey can employ defences at all or some of these stages to deter predation. However, investment in defences is costly unless they are outweighed by conferring some benefit to the bearer. One system that employs multiple defences is that of the entomopathogenic nematode Heterorhabditis bacteriophora and its symbiotic bacterium Photorhabdus luminescens. This nematodeebacterium complex infects and kills soil-dwelling insect larvae, in which they then reproduce and juveniles emerge 2 weeks later. Predation of the infected host cadaver at any point during infection is fatal for the parasitic colony inside. Infected individual…
In vivo Antimicrobial Activity Assessment of a Cauliflower By-Product Extract Against Salmonella Typhimurium
2020
The main objective of this work was to study the antimicrobial effect of a cauliflower by-product infusion into an affordable in vivo model (Caenorhabditis elegans). The infusion demonstrated some protective effect on non-infected and infected worms with Salmonella Typhimurium as indicated by higher survival percentile values (75, 50, 25, and 5% percentiles) as compared with those from worms unexposed to the infusion. The antimicrobial effect of the infusion was evaluated on Salmonella intestinal colonization of infected worms (24, 48, and 96 h post-infection). At 96 h post-infection, the concentration of Salmonella was reduced around 2 log cycles in infected cauliflower treated group (p < …
Metagenomics Analysis Reveals an Extraordinary Inner Bacterial Diversity in Anisakids (Nematoda: Anisakidae) L3 Larvae
2021
This article belongs to the Special Issue Parasitic Diseases from Wild Animals with Emphasis in Zoonotic Infections.