Search results for "Host"

Data from: Getting there and around: host range oscillations during colonisation of the Canary Islands by the parasitic nematode Spauligodon

2017

Episodes of expansion and isolation in geographic range over space and time, during which parasites have the opportunity to expand their host range, are linked to the development of host-parasite mosaic assemblages and parasite diversification. In this study we investigated whether island colonisation events lead to host range oscillations in a taxon of host-specific parasitic nematodes of the genus Spauligodon in the Canary Islands. We further investigated if range oscillations also resulted in shifts in host breadth (i.e. specialization), as expected for parasites on islands. Parasite phylogeny and divergence time estimates were inferred from molecular data with Bayesian methods. Host div…

Within-lake dynamics in the similarity of parasite assemblages of perch (Perca fluviatilis).

2005

Although parasite communities have been studied extensively in recent years, spatial and temporal variation in factors affecting the communities has received less attention. This paper examined the similarity of parasite assemblages of perch (Perca fluviatilis) in 18 locations within a single lake in relation to geographical distance and temporal dynamics in the host and parasite populations. We expected that in the present study-scale where distinct but potentially interacting host subpopulations could occur, similarity of the assemblages could be affected by seasonal dynamics in host movements particularly during the spawning period. Parasite species showed differences in infection levels…

Zschokkella hildae Auerbach, 1910: phylogenetic position, morphology, and location in cultured Atlantic cod.

2010

Abstract The myxozoan Zschokkella hildae Auerbach, 1910, was detected with a prevalence of 100% in cultured Atlantic cod, Gadus morhua L. aged 1+ from a culture facility on the west coast of Scotland. Sporogonic stages of Z. hildae, plasmodia producing 2–5 mature spores, were located predominantly in the collecting ducts and ureters of the kidney, and spores were present in the urine collected from the bladder. Less frequently, plasmodia were detected in the interstitial tissue of the kidney. The parasite prevalence in cultured fish was considerably higher than reported in wild fish but no obvious signs of pathology were detected. SSU rDNA sequencing and phylogenetic analysis showed that Z.…

Parasite specificity in Podarcis bocagei and P. carbonelli (Lacertidae) from NW Portugal: a host-parasite history

2015

Host parasite specificity is related to several factors including the type of life cycle of the parasite, the habitat occupied by both parasites and hosts, and the food habits of the hosts. In this work, gastrointestinal helminths in two congeneric lacertid lizards, Podarcis bocagei and Podarcis carbonelli living in sintopy, have been analysed. Out of four helminth species found, three of them, the trematode Brachylaima sp., the cestode Oochoristica gallica and the nematode Skrjabinelazia hoffmanni, have indirect life cycles while the nematode Spauligodon carbonelli has a direct life cycle. Heteroxenous helminths showed low host specificity whereas S. carbonelli may be placed at an intermed…

Collective defence portfolios of ant hosts shift with social parasite pressure

2014

Host defences become increasingly costly as parasites breach successive lines of defence. Because selection favours hosts that successfully resist parasitism at the lowest possible cost, escalating coevolutionary arms races are likely to drive host defence portfolios towards ever more expensive strategies. We investigated the interplay between host defence portfolios and social parasite pressure by comparing 17 populations of two Temnothorax ant species. When successful, collective aggression not only prevents parasitation but also spares host colonies the cost of searching for and moving to a new nest site. However, once parasites breach the host's nest defence, host colonies should resor…

Patterns of cercarial production from Diplostomum spathaceum: terminal investment or bet hedging?

2004

In the production of the infective cercariae of trematodes, the terminal investment hypothesis of life-history theory predicts that the rate of host exploitation and cercarial production should increase during the period of cercarial shedding since the reproductive value of the parasite decreases during this period. In contrast, a bet hedging hypothesis that focuses on the success of transmission when host contact rate is variable predicts that cercarial production should decrease in an attempt to keep the host alive for longer and thus would increase the probability of successful transmission. We examined these two hypotheses under laboratory conditions and recorded the production ofDiplos…

Effect of dual biotic stress on plant volatile synomones used by an egg parasitoid

Plants respond to arthropod herbivory with the induction of volatiles called herbivore-induced plant volatiles (HIPVs). These volatiles appear to be important sources of information that attract parasitoids. Parasitic wasps foraging decisions are often affected by community characteristics such as community diversity and complexity. As part of a complex habitat, the presence of unsuitable hosts (non-host) may affect foraging behavior of parasitoids. In this chapter, we outline the importance of the presence of unsuitable herbivores on the behavioral responses of parasitoids. First we review the foraging behavior of parasitoid in tritrophic interaction. Then we focus on foraging behavior by …

Transfusion-associated graft-versus-host disease-report of two further cases with an immunohistochemical analysis

1994

Summary Transfusion-associated graft-vs.-host disease (tGVHD) is a severe disease usually affecting immunocompromised hosts with haematological neoplasia. Two patients with acute leukaemia are reported, who developed fatal tGVHD after blood transfusions. Intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1) and endothelial leucocyte adhesion molecule 1 (ELAM-1) expression and the CD4/CD8 ratio were assessed in lesional skin. ICAM-1 was strongly expressed on epidermal keratinocytes and endothelial cells (EC) and correlated with HLA-DR staining. VCAM-1 was strongly expressed on EC in the superficial dermal vessels. ELAM-1 stained weakly on EC in some of the su…

Immunohistochemical markers for histopathological diagnosis and differentiation of acute cutaneous graft‐versus‐host disease

2021

Graft-versus-host disease (GvHD) is a major complication following stem-cell or solid-organ transplantation. Accurate diagnosis of cutaneous GvHD is challenging, given that drug eruptions and viral rashes may present with similar clinical/histological manifestations. Specific markers are not available. We performed the histological examination of biopsy samples from acute GvHD (aGvHD; n = 54), Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN; n = 27), maculopapular drug eruption (MDE; n = 26) and healthy controls (n = 26). Samples of aGvHD showed a decrease in Langerhans cells (LC, p = 0.0001) and an increase in macrophages (MΦ, p = 0.0001) compared to healthy skin. Compared to …

Peripheral Calcifying Odontogenic Cyst : a rare case report

2018

The Calcifying Odontogenic Cyst (COC) is a simple cyst lined by ameloblastoma-like epithelium with ghost cells. The peripheral COC is a rare lesion and few reports have been published considering its clinical and histopathological features. This article aimed to report on a case of a peripheral COC, discussing its clinical, imaginological and histopathological features. A 9-year-old male patient presented a 10x5 mm painless nodule in the palatal mucosa of the left central incisor. Panoramic, occlusal and periapical radiographs did not show alterations. A computed tomography exam showed a slight soft tissue swelling located in the palatal mucosa of the left maxillary central incisor. An exci…