scholarly journals Identifying a key host in an acanthocephalan-amphipod system

Parasitology ◽  
2015 ◽  
Vol 142 (13) ◽  
pp. 1588-1594 ◽  
Author(s):  
ALEXANDRE BAUER ◽  
THIERRY RIGAUD
Keyword(s):  
Life Cycle ◽  
Parasite Infection ◽  
Parasite Transmission ◽  
Intermediate Hosts ◽  
Parasite Life Cycle ◽  
Gammarus Fossarum ◽  
Pomphorhynchus Laevis ◽  
Gammarus Roeseli ◽  
Trophically Transmitted Parasites ◽  
Behavioural Manipulation

SUMMARYTrophically transmitted parasites may use multiple intermediate hosts, some of which may be ‘key-hosts’, i.e. contributing significantly more to the completion of the parasite life cycle, while others may be ‘sink hosts’ with a poor contribution to parasite transmission. Gammarus fossarum and Gammarus roeseli are sympatric crustaceans used as intermediate hosts by the acanthocephalan Pomphorhynchus laevis. Gammarus roeseli suffers higher field prevalence and is less sensitive to parasite behavioural manipulation and to predation by definitive hosts. However, no data are available on between-host differences in susceptibility to P. laevis infection, making it difficult to untangle the relative contributions of these hosts to parasite transmission. Based on results from estimates of prevalence in gammarids exposed or protected from predation and laboratory infections, G. fossarum specimens were found to be more susceptible to P. laevis infection. As it is more susceptible to both parasite infection and manipulation, G. fossarum is therefore a key host for P. laevis transmission.

Parasite life-cycle studies: a plea to resurrect an old parasitological tradition

2017 ◽  
Vol 91 (6) ◽  
pp. 647-656 ◽  
Author(s):  
I. Blasco-Costa ◽  
R. Poulin
Keyword(s):  
Life Cycle ◽  
Large Scale ◽  
Integrative Taxonomy ◽  
Life Cycles ◽  
Intermediate Hosts ◽  
Parasite Life Cycle ◽  
Quantitative Evidence ◽  
Research Areas ◽  
Food Web Ecology ◽  
And Control

AbstractMany helminth taxa have complex life cycles, involving different life stages infecting different host species in a particular order to complete a single generation. Although the broad outlines of these cycles are known for any higher taxon, the details (morphology and biology of juvenile stages, specific identity of intermediate hosts) are generally unknown for particular species. In this review, we first provide quantitative evidence that although new helminth species are described annually at an increasing rate, the parallel effort to elucidate life cycles has become disproportionately smaller over time. We then review the use of morphological matching, experimental infections and genetic matching as approaches to elucidate helminth life cycles. Next we discuss the various research areas or disciplines that could benefit from a solid knowledge of particular life cycles, including integrative taxonomy, the study of parasite evolution, food-web ecology, and the management and control of parasitic diseases. Finally, we end by proposing changes to the requirements for new species descriptions and further large-scale attempts to genetically match adult and juvenile helminth stages in regional faunas, as part of a plea to parasitologists to bring parasite life-cycle studies back into mainstream research.

scholarly journals Differential influence of Pomphorhynchus laevis (Acanthocephala) on brain serotonergic activity in two congeneric host species

2006 ◽  
Vol 3 (1) ◽  
pp. 69-72 ◽  
Author(s):  
Luke Tain ◽  
Marie-Jeanne Perrot-Minnot ◽  
Frank Cézilly
Keyword(s):  
Invasive Species ◽  
Host Species ◽  
Life Cycles ◽  
Immunocytochemical Staining ◽  
Intermediate Hosts ◽  
Pomphorhynchus Laevis ◽  
Gammarus Roeseli ◽  
Serotonergic Activity ◽  
Local Host ◽  
Acanthocephalan Parasite

The physiological mechanisms by which parasites with complex life cycles manipulate the behaviour of their intermediate hosts are still poorly understood. In Burgundy, eastern France, the acanthocephalan parasite Pomphorhynchus laevis inverses reaction to light in its amphipod host Gammarus pulex , but not in Gammarus roeseli , a recent invasive species. Here, we show that this difference in manipulation actually reflects a difference in the ability of the parasite to alter brain serotonergic (5-HT) activity of the two host species. Injection of 5-HT in uninfected individuals of both host species was sufficient to inverse reaction to light. However, a difference in brain 5-HT immunocytochemical staining levels between infected and uninfected individuals was observed only in G. pulex . Local adaptation of the parasite to the local host species might explain its inability to manipulate the behaviour and nervous system of the invasive species.

scholarly journals Kinesin-8B controls basal body function and flagellum formation and is key to malaria parasite transmission

2019 ◽  
Author(s):  
Mohammad Zeeshan ◽  
David J. P. Ferguson ◽  
Steven Abel ◽  
Alana Burrrell ◽  
Edward Rea ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Life Cycle ◽  
Live Cell Imaging ◽  
Malaria Parasite ◽  
Cell Imaging ◽  
Male Gamete ◽  
Live Cell ◽  
Basal Bodies ◽  
Parasite Transmission ◽  
Parasite Life Cycle

AbstractEukaryotic flagella are conserved microtubule-based organelles that drive cell motility. Plasmodium, the causative agent of malaria, has a single flagellate stage: the male gamete in the mosquito. Three rounds of endomitotic division together with an unusual mode of flagellum assembly rapidly produce eight motile gametes. These processes are tightly coordinated but their regulation is poorly understood. To understand this important developmental stage, we studied the function and location of the microtubule-based motor kinesin-8B, using gene-targeting, electron microscopy and live cell imaging. Deletion of the kinesin-8B gene showed no effect on mitosis but disrupted 9+2 axoneme assembly and flagellum formation during male gamete development and also completely ablated parasite transmission. Live cell imaging showed that kinesin-8B-GFP did not colocalise with kinetochores in the nucleus but instead revealed dynamic, cytoplasmic localisation with the basal bodies and the assembling axoneme during flagellum formation. We thus uncovered an unexpected role for kinesin-8B in parasite flagellum formation that is vital for the parasite life cycle.

An acanthocephalan parasite boosts the escape performance of its intermediate host facing non-host predators

Parasitology ◽  
2008 ◽  
Vol 135 (8) ◽  
pp. 977-984 ◽  
Author(s):  
V. MEDOC ◽  
J.-N. BEISEL
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Definitive Host ◽  
Complex Life Cycle ◽  
Escape Performance ◽  
Intermediate Hosts ◽  
Host Condition ◽  
Gammarus Roeseli ◽  
The Cost ◽  
Acanthocephalan Parasite

SUMMARYAmong the potential effects of parasitism on host condition, the ‘increased host abilities’ hypothesis is a counterintuitive pattern which might be predicted in complex-life-cycle parasites. In the case of trophic transmission, a parasite increasing its intermediate host's performance facing non-host predators improves its probability of transmission to an adequate, definitive host. In the present study, we investigated the cost of infection with the acanthocephalanPolymorphus minutuson the locomotor/escape performance of its intermediate host, the crustaceanGammarus roeseli. This parasite alters the behaviour of its intermediate host making it more vulnerable to predation by avian definitive hosts. We assessed the swimming speeds of gammarids using a stressful treatment and their escape abilities under predation pressure. Despite the encystment ofP. minutusin the abdomen of its intermediate host, infected amphipods had significantly higher swimming speeds than uninfected ones (increases of up to 35%). Furthermore, when interacting with the non-host crustacean predatorDikerogammarus villosus, the highest escape speeds and greatest distances covered by invertebrates were observed for parasitized animals. The altered behaviour observed among the manipulated invertebrates supported the ‘increased host abilities’ hypothesis, which has until now remained untested experimentally. The tactic of increasing the ability of infected intermediate hosts to evade potential predation attempts by non-host species is discussed.

Inter-population variation in the intensity of host manipulation by the fish acanthocephalan Pomphorhynchus tereticollis: are differences driven by predation risk?

Parasitology ◽  
2019 ◽  
Vol 146 (10) ◽  
pp. 1296-1304 ◽  
Author(s):  
M. Fayard ◽  
F. Cezilly ◽  
M.-J. Perrot-Minnot
Keyword(s):  
Population Variation ◽  
Total Protein Content ◽  
Host Manipulation ◽  
Intermediate Hosts ◽  
Biomass Density ◽  
Refuge Use ◽  
Behavioural Alteration ◽  
Trophically Transmitted Parasites ◽  
Induced Changes ◽  
Behavioural Manipulation

AbstractMany trophically-transmitted parasites induce behavioural alteration in their intermediate hosts that tend to increase host vulnerability to predation. Inter-population variability in parasite-induced alterations is expected to arise from variable local opportunities for trophic transmission. Yet, this hypothesis has not been investigated so far. We addressed the issue in four populations of the fish parasite Pomphorhynchus tereticollis (Acanthocephala), using variable fish biomass density as a proxy for transmission opportunities. We found variation in the intensity of parasite-induced changes in phototaxis and refuge use among populations. Two of the populations with the lowest predator biomass exhibited the highest levels of behavioural manipulation and prevalence, as expected at low transmission opportunities. They also exhibited micro-habitat segregation between infected and uninfected gammarids in the field. In addition, infection had variable effects on two physiological defence systems, immunity and antioxidant capacity, and on total protein content. Overall, our study brings partial support to the prediction that host manipulation and prevalence should be higher at low predator biomass. Although stronger evidence should be sought by increasing population replicates, our study points to the importance of the ecological context, specifically transmission opportunities brought about by predation pressure, for the evolution of parasite manipulation in trophically-transmitted parasites.

The Parasites Recorded From Trichosurus Species (Marsupialia: Phalangeridae).

1995 ◽  
Vol 22 (3) ◽  
pp. 311 ◽  
Author(s):  
KL Viggers ◽  
DM Spratt
Keyword(s):  
Biological Control ◽  
Life Cycle ◽  
New Zealand ◽  
Fasciola Hepatica ◽  
Parasite Infection ◽  
Trichosurus Vulpecula ◽  
Pathological Changes ◽  
Histopathological Changes ◽  
Intermediate Hosts ◽  
Numerous Species

This review outlines the known endoparasites and ectoparasites of the brushtail possums Trichosurus vulpecula and T. caninus in Australia and T. vulpecula in New Zealand. Associated gross and histopathological changes in the host as a result of parasite infection are also described. Protozoan, cestode and nematode endoparasites have been found in both T. vulpecula (4 protozoa, one cestode and 25 nematodes) and T. caninus (2 protozoa, one cestode and 8 nematodes). The trematode Fasciola hepatica has been recorded only from T. vulpecula, in which it is associated with extensive pathological changes in the liver. Numerous species of fleas, ticks and mites occur on T. caninus (one flea, 4 ticks and 9 mites) and T. vulpecula (7 fleas, 11 ticks and 18 mites) in Australia, but only mites (4 species) occur on T. vulpecula in New Zealand. The only parasite with an indirect life cycle that occurs in T. vulpecula in New Zealand is the cestode Bertiella trichosuri. Other parasites that require intermediate hosts to complete their life cycle are absent. Further studies are required to investigate the effects of parasites on the health and fecundity of T. vulpecula and T. caninus in Australia to determine their potential as direct or indirect agents for the biological control of T. vulpecula in New Zealand.

scholarly journals Kinesin-8B controls basal body function and flagellum formation and is key to malaria transmission

2019 ◽  
Vol 2 (4) ◽  
pp. e201900488 ◽  
Author(s):  
Mohammad Zeeshan ◽  
David JP Ferguson ◽  
Steven Abel ◽  
Alana Burrrell ◽  
Edward Rea ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Life Cycle ◽  
Gene Targeting ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Male Gamete ◽  
Live Cell ◽  
Basal Bodies ◽  
Parasite Transmission ◽  
Parasite Life Cycle

Eukaryotic flagella are conserved microtubule-based organelles that drive cell motility. Plasmodium, the causative agent of malaria, has a single flagellate stage: the male gamete in the mosquito. Three rounds of endomitotic division in male gametocyte together with an unusual mode of flagellum assembly rapidly produce eight motile gametes. These processes are tightly coordinated, but their regulation is poorly understood. To understand this important developmental stage, we studied the function and location of the microtubule-based motor kinesin-8B, using gene-targeting, electron microscopy, and live cell imaging. Deletion of the kinesin-8B gene showed no effect on mitosis but disrupted 9+2 axoneme assembly and flagellum formation during male gamete development and also completely ablated parasite transmission. Live cell imaging showed that kinesin-8B–GFP did not co-localise with kinetochores in the nucleus but instead revealed a dynamic, cytoplasmic localisation with the basal bodies and the assembling axoneme during flagellum formation. We, thus, uncovered an unexpected role for kinesin-8B in parasite flagellum formation that is vital for the parasite life cycle.

Taeniasis in a German Shepherd Pup: A Case Report

2019 ◽  
Vol 15 (01) ◽  
pp. 83-84
Author(s):  
B J Thakre ◽  
Joice P Joseph ◽  
Binod Kumar ◽  
Nilima Brahmbhatt ◽  
Krishna Gamit
Keyword(s):  
Case Report ◽  
Life Cycle ◽  
Definitive Host ◽  
Gastrointestinal Diseases ◽  
Intermediate Hosts ◽  
German Shepherd ◽  
Taenia Hydatigena ◽  
Taenia Multiceps ◽  
Taenia Crassiceps ◽  
Dipylidium Caninum

Taenia spp. are long, segmented, parasitic tapeworms and are relatively uncommon in canine gastrointestinal diseases compared to other tapeworms like Dipylidium caninum. These parasites have an indirect life cycle, cycling between definitive and intermediate hosts. Dogs act as definitive hosts of different species of Taenia including Taenia multiceps, Taenia serialis, Taenia crassiceps, Taenia hydatigena, Taenia pisiformis, etc. Taenia multiceps is of greatest zoonotic relevance in human. In the definitive host, it causes only mild infection. Larvae are more likely to cause disease than adult tapeworms. Taeniasis in pets should be cautiously handled because of its zoonotic importance. This communication reports a case of 3 months old pup suffering from Taenia infection that was successfully managed with a combination of praziquantel and fenbendazole.

scholarly journals Effects of parasites upon non-host predator avoidance behaviour in native and invasive gammarids

Parasitology ◽  
2020 ◽  
pp. 1-7
Author(s):  
Sajad Farahani ◽  
Per J. Palsbøll ◽  
Ido Pen ◽  
Jan Komdeur
Keyword(s):  
Invasive Species ◽  
Definitive Host ◽  
Predator Avoidance ◽  
Gasterosteus Aculeatus ◽  
Chemical Cues ◽  
Critical Role ◽  
Fundamental Question ◽  
Intermediate Hosts ◽  
Gammarus Fossarum ◽  
Acanthocephalan Parasite

Abstract The acanthocephalan parasite, Polymorphus minutus, manipulates its intermediate hosts' (gammarids) behaviour, presumably to facilitate its transmission to the definitive hosts. A fundamental question is whether this capability has evolved to target gammarids in general, or specifically sympatric gammarids. We assessed the responses to chemical cues from a non-host predator (the three-spined sticklebacks Gasterosteus aculeatus) in infected and non-infected gammarids; two native (Gammarus pulex and Gammarus fossarum), and one invasive (Echinogammarus berilloni) species, all sampled in the Paderborn Plateau (Germany). The level of predator avoidance was assessed by subjecting gammarids to choice experiments with the presence or absence of predator chemical cues. We did not detect any behavioural differences between uninfected and infected G. pulex and E. berilloni, but an elevated degree of predator avoidance in infected G. fossarum. Avoiding non-host predators may ultimately increase the probability of P. minutus' of predation by the definitive host. Our results suggested that P. minutus' ability to alter the host's behaviour may have evolved to specifically target sympatric gammarid host species. Uninfected gammarids did not appear to avoid the non-host predator chemical cues. Overall the results also opened the possibility that parasites may play a critical role in the success or failure of invasive species.

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