Feces from 15 dogs at 2 different foxhound kennels in the U.K. were examined microscopically for the presence of oocysts of Neospora caninum. One sample containing approximately 400 candidate oocysts per gram was positive in a polymerase chain reaction (PCR) using N. caninum-specific primers. In a sample taken 4 mo later from the same hound, N. caninum oocysts were again detected visually and by PCR. This is the third reported case of a dog naturally excreting oocysts of N. caninum and suggests that oocyst excretion can occur over a relatively long period of time in some circumstances or that reshedding may occur

Bizarro, Cristiano V.

Espinoza, Ingrid

Farias, Sandra

Ferreira, Henrique B.

Galanti Garrone, Norbel

Markoski, Melissa M.

Zaha, Arnaldo

Unsporulated oocysts were detected in the feces of an Arabian red fox (Vulpes vulpes arabica) between 6 and 8 days after it had been fed meat from Arabian mountain gazelles (Gazella gazella) known to contain sarcocysts. No oocysts were discovered in the feces of other experimental cubs, although sporocysts of Sarcocystis spp. were passed subsequently by all cubs that were fed gazelle meat, including those fed with reem (G. subgutturosa marica). The oocysts sporulated in 3 days at room temperature (25 ± 2 C); they were 10.9 ± 1.4 × 10.1 ± 1.3 μm, with 2 sporocysts measuring 6.0 ± 0.6 × 4.7 ± 0.8 μm, each with 4 sporozoites. Sporulated oocysts were identified as those of Hammondia heydorni using molecular and standard morphometric techniques. Sequence differences between 2 fox and 3 dog isolates of H. heydorni were detected and allowed differentiation between the 2 populations of the organism. The involvement of Neospora caninum was excluded using molecular methods. The Arabian red fox and the Arabian mountain gazelle in Saudi Arabia are new, definitive and intermediate hosts for H. heydorni

Mohammed, OB

Davies, AJ

Hussein, HS

Daszak, P

Ellis, JT

OPUS - University of Technology Sydney

Journal of Parasitology

Hammondia heydorni from the Arabian mountain gazelle and red fox in Saudi Arabia

Adult and mobile preadult sea lice L. salmonis were incubated with mucus samples from rainbow trout (Oncorhynchus mykiss), coho salmon (O. kisutch), Atlantic salmon (Salmo salar), and winter flounder (Pseudopleuronectes americanus) to determine the response of L. salmonis to fish skin mucus as assessed by the release of proteases and alkaline phosphatase. There was variation in the release of respective enzymes by sea lice in response to different fish. As well, sea lice collected from British Columbia responded differently than New Brunswick sea lice to coho salmon mucus. Fish mucus and seawater samples were also analysed using protease gel zymography to observe changes in the presence of low molecular weight (LMW) proteases after L. salmonis incubation. Significantly higher proportions of sea lice secreted multiple bands of L. salmonis-derived LMW proteases after incubation with rainbow trout or Atlantic salmon mucus in comparison with seawater, coho salmon, or winter flounder mucus. Susceptibility to L. salmonis infections may be related to the stimulation of LMW proteases from L. salmonis by fish mucus. The resistance of coho salmon to L. salmonis infection may be due to agents in their mucus that block the secretion of these LMW proteases or factors may exist in the mucus of susceptible species that stimulate their release..Source type: Electronic(1)neil.ross@nrc.c

IslandScholar

Enzymes released from Lepeophtheirus salmonis in response to mucus from different salmonids

International audienceIn this comparative behavioral study, the effect of infection with Schistosoma mansoni on its snail intermediate host Biomphalaria glabrata was investigated. Three groups of snails were compared for their activity: (1) uninfected, (2) infected with male parasites, and (3) infected with female parasites. In solitary movement trials, uninfected snails traveled greater distances at faster rates, explored more surface area, and had shorter rest periods than snails infected with either male or female schistosomes. In Y-maze experiments designed to determine attraction, the uninfected snails more often and more quickly moved toward other snails than the infected individuals. Snails from all 3 groups were more attracted to infected individuals than to uninfected ones. There was no difference in attraction toward snails infected with male or female parasites. These experiments provide evidence that behavioral alterations as a result of infection may lead to aggregation of infected snails in the field. We propose that such an effect may result in enhanced parasite transmissio

Boissier, J.

Rivera, E.R.

Moné, H.

Archive Ouverte en Sciences de l'Information et de la Communication

Altered behavior of the snail Biomphalaria glabrata as a result of infection with Schistosoma mansoni

We have previously demonstrated that cardiac myocytes isolated from the hearts of adult dogs develop rapid repetitive cytosolic Ca2+ transients, membrane depolarization, and cell contraction by mobilization of sarcoplasmic reticulum Ca2+ stores when exposed to a soluble factor from the trypomastigotes of Trypanosoma cruzi. These findings led us to investigate the regulatory mechanisms of cytosolic Ca2+ in cardiac tissues from dogs chronically infected with T. cruzi. Expression of the plasma membrane calcium pump (PMCA) RNA and protein was determined by Northern and Western blotting, respectively, followed by densitometric analyses. A 642-bp PMCA 1b complementary DNA probe derived from canine epicardial tissue hybridized to 2 major transcripts (7.3 and 5.3 kb) in canine epicardium. Expression of the dominant transcript (7.3 kb) was 77% greater in cardiac tissues obtained from dogs with chronic T. cruzi infection (140 days after inoculation) in comparison with constitutive expression levels in normal dogs. Monoclonal antibody 5F10, known to recognize all isoforms of the PMCA, was used to detect expression of the PMCA protein in epicardial tissue. Expression of a 142-kDa protein was increased by 58% in the cardiac tissues of infected dogs when compared with those from uninfected dogs. To establish a link between the upregulation of PMCA in dogs chronically infected with Chagas disease and the ventricular-based arrhythmias and myocardial failure that occur during this stage of disease both in dogs and humans, further study will be required.Accession Number: 12760659. Language: English. Language Code: eng. Date Revised: 20101118. Date Created: 20030522. Date Completed: 20030603. Update Code: 20111122. Publication Type: Journal Article. Journal ID: 7803124. Publication Model: Print. Cited Medium: Print. NLM ISO Abbr: J. Parasitol. Linking ISSN: 00223395. Subset: IM. Date of Electronic Publication: 20030401; ID: 1276065

Upregulation of cardiac cell plasma membrane calcium pump in a canine model of Chagas disease

Mesocestoides corti is a suitable model for studying cestode development because of its ability to reproduce asexually and segment in vitro. The cultured parasite is also capable of sexual differentiation and, probably, reproduction. To establish conditions that increase the efficiency of in vitro M. corti larvae (tetrathyridia) segmentation, we tested the effects of an inducing agent and some physical parameters in cultures. We found that a 5% CO2-95% N2 gas phase, an incubation temperature of 39 C (instead of 37 C), and a 24-hr pretreatment with trypsin (105 BAEE/ml, BAEE = Nα-benzoil-L-arginine ethyl ester unit of trypsin activity) in Roswell Park Memorial Institute (RPMI) 1640 medium supplemented with 20% fetal bovine serum (FBS) are able to increase individually or synergistically the segmentation rate of tetrathyridia. A segmentation rate of up to 100% was achieved on day 4 of culture, when all these conditions were used simultaneously, in comparison with an average rate of 40% 

Repositorio Académico de la Universidad de Chile

In vitro segmentation induction of Mesocestoides corti (cestoda) tetrathyridia

To investigate the role of intestinal lamina propria lymphocytes (LPL) and intraepithelial lymphocytes (IEL) in controlling Cryptosporidium parvum infection, changes in their phenotypes and functional properties were studied after induction of primary and challenge infections in immunocompetent mice. As shown by oocyst-shedding patterns, the challenge-infected group recovered more rapidly from infection than did the primary-infected group. In LPL, proportions of activated CD4+, CD25+, IgG1+, IgA+, and CD4+/IFN-γ+ cells increased significantly in the primary-infected group compared with controls. In the challenge-infected group, proportions of these cells decreased. The antigen-specific IgA level was elevated significantly among LPL of both primary- and challenge-infected groups. Among IEL, proportions of activated CD8+, T cell receptor (TCR) γδ+, and CD8+/TCR γδ+ cells increased significantly in the challenge-infected group compared with controls and the primary-infected group; their cytotoxicity also was enhanced. However, the proportion of IEL expressing Th1 cytokines was lower than that among LPL in both infected groups. The results suggest that LPL play a more important role in protection against a primary infection with C. parvum, through the production of IFN-γ and IgA, whereas IEL are more involved in protection against a challenge infection, through enhanced cytotoxicity.ope

용태순

Yonsei University Medical Library Open Access Repository

Role of Murine Intestinal Intraepithelial Lymphocytes and Lamina Propria Lymphocytes against Primary and Challenge Infections with Cryptosporidium parvum

McGarry, J.W.

Stockton, C. M.

Williams, Diana J.L.

Trees, Alexander J.

LSTM Online Archive

Protracted shedding of oocysts of Neospora caninum by a naturally infected foxhound

Boissier, Jérôme

Hal-Diderot

Morgan, J. A. T.

Dejong, R. J.

Lwambo, N. J. S.

Mungai, B. N.

Mkoji, G. M.

Loker, E. S.

University of Queensland eSpace

First report of a natural hybrid between Schistosoma mansoni and S. rodhaini

The main objective of this investigation was to examine the ultrastructural features of gills from rainbow trout experimentally infected with Loma salmonae to determine the morphological events that occur during the late stages of development of this parasite. Peripheral distribution of the mature parasites inside round xenomas was observed at weeks 5 and 6 postexposure (PE), but eventually the parasite occupied the entire xenoma. Degenerative changes were observed only in immature parasites at week 7 PE, and eventually an inflammatory reaction with a cellular infiltration was directed against mature spores. Round, flattened, and irregular shaped xenomas were observed at week 8 PE. The round xenomas showed a severe inflammatory response with disintegration of the xenoma membrane. This event was accompanied by eversion of polar tubes within the attacked xenoma and by the simultaneous presence of 2 tubular appendages, the type I and II tubules. Flattened xenomas were observed below the endothelium of gill lamella arteries. The irregular xenomas were located in the connective tissue of the gill filament and showed multiple projections occupied by spores. Both flattened and irregular xenomas showed no evidence of inflammatory reaction. An earlier proposed hypothesis is expanded to explain how L. salmonae is implanted beneath lamellar endothelium and within filament connective tissue.LR: 20061115; PUBM: Print; JID: 7803124; ppublishSource type: Electronic(1

Ultrastructural study of the late stages of Loma salmonae development in the gills of experimentally infected rainbow trout

http://archive.lstmed.ac.uk/2609/1/Protracted_shedding_of_oocysts_of_neospora.pdf

'Hammondia heydorni' from the Arabian mountain gazelle and red fox in Saudi Arabia

'Hammondia heydorni' from the Arabian mountain gazelle and red fox in Saudi Arabia

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OPUS - University of Technology Sydney

IslandScholar

Archive Ouverte en Sciences de l'Information et de la Communication

IslandScholar

Repositorio Académico de la Universidad de Chile

Yonsei University Medical Library Open Access Repository

LSTM Online Archive

Hal-Diderot

University of Queensland eSpace

IslandScholar