scholarly journals Host-parasite interactions between the piranha Pygocentrus nattereri (Characiformes: Characidae) and isopods and branchiurans (Crustacea) in the rio Araguaia basin, Brazil

2004 ◽  
Vol 2 (2) ◽  
pp. 93-98 ◽  
Author(s):  
Lucélia Nobre Carvalho ◽  
Rafael Arruda ◽  
Kleber Del-Claro
Keyword(s):  
Body Size ◽  
Mean Intensity ◽  
Feeding Sites ◽  
Host Parasite Interactions ◽  
Ecological Aspects ◽  
Field Samples ◽  
Pygocentrus Nattereri ◽  
The Tropics ◽  
Host Parasite ◽  
Ventral Area

In the tropics, studies on the ecology of host-parasite interactions are incipient and generally related to taxonomic aspects. The main objective of the present work was to analyze ecological aspects and identify the metazoan fauna of ectoparasites that infest the piranha, Pygocentrus nattereri. In May 2002, field samples were collected in the rio Araguaia basin, State of Goiás (Brazil). A total of 252 individuals of P. nattereri were caught with fishhooks and 32.14% were infested with ectoparasite crustaceans. The recorded ectoparasites were branchiurans, Argulus sp. and Dolops carvalhoi and the isopods Braga patagonica, Anphira branchialis and Asotana sp. The prevalence and mean intensity of branchiurans (16.6% and 1.5, respectively) and isopods (15.5% and 1.0, respectively) were similar. Isopods were observed in the gills of the host; branchiurans were more frequent where the skin was thinner, and facilitated attachment and feeding. The ventral area, the base of the pectoral fin and the gular area were the most infested areas. The correlations between the standard length of the host and the variables intensity and prevalence of crustaceans parasitism, were significant only for branchiurans (rs = 0.2397, p = 0.0001; chi2 = 7.97; C = 0.19). These results suggest that both feeding sites and body size probably play an important role in the distribution and abundance of ectoparasites.

scholarly journals Mesoscale spatiotemporal variability in a complex host-parasite system influenced by intermediate host body size

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3675 ◽  
Author(s):  
Sara M. Rodríguez ◽  
Nelson Valdivia
Keyword(s):  
Body Size ◽  
Parasite Burden ◽  
Spatiotemporal Variability ◽  
Intermediate Hosts ◽  
Host Body ◽  
Host Parasite Interactions ◽  
Essential Components ◽  
Host Parasite ◽  
Parasite Exposure ◽  
Host Body Size

Background Parasites are essential components of natural communities, but the factors that generate skewed distributions of parasite occurrences and abundances across host populations are not well understood. Methods Here, we analyse at a seascape scale the spatiotemporal relationships of parasite exposure and host body-size with the proportion of infected hosts (i.e., prevalence) and aggregation of parasite burden across ca. 150 km of the coast and over 22 months. We predicted that the effects of parasite exposure on prevalence and aggregation are dependent on host body-sizes. We used an indirect host-parasite interaction in which migratory seagulls, sandy-shore molecrabs, and an acanthocephalan worm constitute the definitive hosts, intermediate hosts, and endoparasite, respectively. In such complex systems, increments in the abundance of definitive hosts imply increments in intermediate hosts’ exposure to the parasite’s dispersive stages. Results Linear mixed-effects models showed a significant, albeit highly variable, positive relationship between seagull density and prevalence. This relationship was stronger for small (cephalothorax length >15 mm) than large molecrabs (<15 mm). Independently of seagull density, large molecrabs carried significantly more parasites than small molecrabs. The analysis of the variance-to-mean ratio of per capita parasite burden showed no relationship between seagull density and mean parasite aggregation across host populations. However, the amount of unexplained variability in aggregation was strikingly higher in larger than smaller intermediate hosts. This unexplained variability was driven by a decrease in the mean-variance scaling in heavily infected large molecrabs. Conclusions These results show complex interdependencies between extrinsic and intrinsic population attributes on the structure of host-parasite interactions. We suggest that parasite accumulation—a characteristic of indirect host-parasite interactions—and subsequent increasing mortality rates over ontogeny underpin size-dependent host-parasite dynamics.

scholarly journals Wildfires modify the parasite loads of invasive cane toads

2021 ◽  
Vol 17 (12) ◽  
Author(s):  
Shannon W. Kaiser ◽  
Matthew J. Greenlees ◽  
Richard Shine
Keyword(s):  
Body Size ◽  
Parasite Load ◽  
Free Living ◽  
Rhinella Marina ◽  
Burned Areas ◽  
Host Parasite Interactions ◽  
Eastern Australia ◽  
Anthropogenic Modifications ◽  
Host Parasite ◽  
Rhabdias Pseudosphaerocephala

The frequency and severity of wildfires are increasing due to anthropogenic modifications to habitats and to climate. Post-fire landscapes may advantage invasive species via multiple mechanisms, including changes to host–parasite interactions. We surveyed the incidence of endoparasitic lungworms ( Rhabdias pseudosphaerocephala ) in invasive cane toads ( Rhinella marina ) in near-coastal sites of eastern Australia, a year after extensive fires in this region. Both the prevalence of infection and number of worms in infected toads increased with toad body size in unburned areas. By contrast, parasite load decreased with toad body size in burned areas. By killing moisture-dependent free-living lungworm larvae, the intense fires may have liberated adult cane toads from a parasite that can substantially reduce the viability of its host. Smaller toads, which are restricted to moist environments, did not receive this benefit from fires.

Host-parasite interactions and the feeding of blood-sucking arthropods

Parasitology ◽  
1969 ◽  
Vol 59 (1) ◽  
pp. 93-104 ◽  
Author(s):  
R. J. Tatchell
Keyword(s):  
Blood Loss ◽  
Blood Meal ◽  
Animal Protein ◽  
Economic Interest ◽  
Host Parasite Interactions ◽  
Blood Sucking ◽  
The Tropics ◽  
Host Parasite

The range of interactions between blood-sucking arthropods and their hosts is enormous and their importance to man would be difficult to overestimate. From the tundra to the tropics man, and animals in which he has a vital nutritional or economic interest, represent to the blood-sucking arthropod a source of animal protein. By their activities in obtaining a blood meal the host may be subjected to minimal inconvenience, acute irritation, or suffer severely from blood loss or from the effects of toxins introduced during feeding. Superimposed upon these situations is an enormous variety of disease agents which may be transmitted to the host by the parasite during or after feeding.

Off-host longevity of the winged dispersal stage ofCarnus hemapterus(Insecta: Diptera) modulated by gender, body size and food provisioning

Parasitology ◽  
2018 ◽  
Vol 146 (2) ◽  
pp. 241-245 ◽  
Author(s):  
Jesús Veiga ◽  
Eulalia Moreno ◽  
Jesús Benzal ◽  
Francisco Valera
Keyword(s):  
Body Size ◽  
Food Provisioning ◽  
Host Parasite Interactions ◽  
Dispersal Stage ◽  
Carnus Hemapterus ◽  
Host Parasite ◽  
The Impact ◽  
Infectious Potential ◽  
Critical Aspects ◽  
Temporal Dispersal

AbstractHighlighting the dispersal ecology of parasites is important for understanding epidemiological, demographic and coevolutionary aspects of host–parasite interactions. Yet, critical aspects of the dispersal stage of parasites, such as longevity and the factors influencing it, are poorly known. Here we study the lifespan of the dispersal stage of an ectoparasitic dipteran,Carnus hemapterus, and the impact of gender, body size and food provisioning on longevity. We found that freshly emerged imagoes survive at most less than 4 days. Longevity increased with body size and, since this parasite exhibits sexual size dimorphism, the bigger females lived longer than males. However, controlling for body size suggests that males lived relatively longer than females. Furthermore, a humid environment and food provisioning (flowers) significantly increased individual life spans. We discuss the relative importance of spatial and temporal dispersal in relation to the infectious potential of this parasite.

Host parasite interactions and pathophysiology in Giardia infections

2011 ◽  
Vol 41 (9) ◽  
pp. 925-933 ◽  
Author(s):  
James A. Cotton ◽  
Jennifer K. Beatty ◽  
Andre G. Buret
Keyword(s):  
Host Parasite Interactions ◽  
Host Parasite

scholarly journals Spatial expression pattern of serine proteases in the blood fluke Schistosoma mansoni determined by fluorescence RNA in situ hybridization

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Lenka Ulrychová ◽  
Pavel Ostašov ◽  
Marta Chanová ◽  
Michael Mareš ◽  
Martin Horn ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Schistosoma Mansoni ◽  
Rna Sequencing ◽  
Serine Proteases ◽  
Expression Patterns ◽  
High Sensitivity ◽  
Host Parasite Interactions ◽  
Highly Sensitive ◽  
Host Parasite

Abstract Background The blood flukes of genus Schistosoma are the causative agent of schistosomiasis, a parasitic disease that infects more than 200 million people worldwide. Proteases of schistosomes are involved in critical steps of host–parasite interactions and are promising therapeutic targets. We recently identified and characterized a group of S1 family Schistosoma mansoni serine proteases, including SmSP1 to SmSP5. Expression levels of some SmSPs in S. mansoni are low, and by standard genome sequencing technologies they are marginally detectable at the method threshold levels. Here, we report their spatial gene expression patterns in adult S. mansoni by the high-sensitivity localization assay. Methodology Highly sensitive fluorescence in situ RNA hybridization (FISH) was modified and used for the localization of mRNAs encoding individual SmSP proteases (including low-expressed SmSPs) in tissues of adult worms. High sensitivity was obtained due to specifically prepared tissue and probes in combination with the employment of a signal amplification approach. The assay method was validated by detecting the expression patterns of a set of relevant reference genes including SmCB1, SmPOP, SmTSP-2, and Sm29 with localization formerly determined by other techniques. Results FISH analysis revealed interesting expression patterns of SmSPs distributed in multiple tissues of S. mansoni adults. The expression patterns of individual SmSPs were distinct but in part overlapping and were consistent with existing transcriptome sequencing data. The exception were genes with significantly low expression, which were also localized in tissues where they had not previously been detected by RNA sequencing methods. In general, SmSPs were found in various tissues including reproductive organs, parenchymal cells, esophagus, and the tegumental surface. Conclusions The FISH-based assay provided spatial information about the expression of five SmSPs in adult S. mansoni females and males. This highly sensitive method allowed visualization of low-abundantly expressed genes that are below the detection limits of standard in situ hybridization or by RNA sequencing. Thus, this technical approach turned out to be suitable for sensitive localization studies and may also be applicable for other trematodes. The results suggest that SmSPs may play roles in diverse processes of the parasite. Certain SmSPs expressed at the surface may be involved in host–parasite interactions. Graphic abstract

scholarly journals Urogenital Schistosomiasis—History, Pathogenesis, and Bladder Cancer

2021 ◽  
Vol 10 (2) ◽  
pp. 205
Author(s):  
Lúcio Lara Santos ◽  
Júlio Santos ◽  
Maria João Gouveia ◽  
Carina Bernardo ◽  
Carlos Lopes ◽  
...  
Keyword(s):  
Schistosoma Haematobium ◽  
Historical Perspective ◽  
Hiv Transmission ◽  
Parasite Infection ◽  
Urogenital Schistosomiasis ◽  
Host Parasite Interactions ◽  
Immunodeficiency Virus ◽  
Recent Outbreak ◽  
Host Parasite ◽  
Female Genital

Schistosomiasis is the most important helminthiasis worldwide in terms of morbidity and mortality. Most of the infections occurs in Africa, which about two thirds are caused by Schistosoma haematobium. The infection with S. haematobium is considered carcinogenic leading to squamous cell carcinoma (SCC) and urothelial carcinoma of the urinary bladder. Additionally, it is responsible for female genital schistosomiasis leading to infertility and higher risk of human immunodeficiency virus (HIV) transmission. Remarkably, a recent outbreak in Corsica (France) drew attention to its potential re-mergence in Southern Europe. Thus far, little is known related to host-parasite interactions that trigger carcinogenesis. However, recent studies have opened new avenues to understand mechanisms on how the parasite infection can lead cancer and other associated pathologies. Here, we present a historical perspective of schistosomiasis, and review the infection-associated pathologies and studies on host–parasite interactions that unveil tentative mechanisms underlying schistosomiasis-associated carcinogenesis.

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