Search results for "Cryptosporidium"
showing 10 items of 41 documents
Speculation on whether a vaccine against cryptosporidiosis is a reality or fantasy
1999
In this paper the authors question whether the development of a vaccine against cryptosporidiosis could be taken into consideration. The necessity and feasibility of such a vaccine for human and veterinary application is discussed. Developmental stages within the life cycle of the parasite that might act as possible targets for vaccine development are summarised, as well as the target antigens offered by molecular biology and immunology studies. Vaccination trials against cryptosporidiosis carried out so far, including the active and passive immunisation approach, are also overviewed. It seems that with respect to a Cryptosporidium vaccine two target groups can be considered: children of th…
Host immune response to Cryptosporidium parvum infection
2010
Species of the genus Cryptosporidium are protozoan parasites (Apicomplexa) that cause gastroenteritis in animals and humans. Of these Cryptosporidium parvum and Cryptosporidium hominis are the major causative agents of human cryptosporidiosis. Whereas infection is self-limiting in the immunocompetent hosts, immunocompromised individuals develop a chronic, life-threatening disease. As specific therapeutic or preventive interventions are not yet available, better understanding of the immune response to the parasite is required. This minireview briefly summarizes the factors involved in the innate and acquired immune response in this pathogen-host interaction with an emphasis on more recent da…
Interactions between bacteria and Cryptosporidium molnari in gilthead sea bream (Sparus aurata) under farm and laboratory conditions
2006
The possible interaction of Cryptosporidium molnari and bacteria in gilthead sea bream (Sparus aurata) was studied. Epidemiological data from a pathological survey under farm conditions were analyzed. In addition, parasite and bacteria burdens were studied in experimental models in which naturally and experimentally parasitized fish were challenged with a particular strain of Vibrio harveyi (H57). All the bacteria species present were studied. Under farm conditions, the parasite was more prevalent when mortality or morbidity cases (study C) occurred than in randomly sampled fish (study B). In study C, parasite abundance was significantly higher in bacteria-negative fish, and total bacteria …
Failure to differentiate Cryptosporidium parvum from C. meleagridis based on PCR amplification of eight DNA sequences.
1998
ABSTRACT In order to determine the specificities of PCR-based assays used for detecting Cryptosporidium parvum DNA, eight pairs of previously described PCR primers targeting six distinct regions of the Cryptosporidium genome were evaluated for the detection of C. parvum , the agent of human cryptosporidiosis, and C. muris , C. baileyi , and C. meleagridis , three Cryptosporidium species that infect birds or mammals but are not considered to be human pathogens. The four Cryptosporidium species were divided into two groups: C. parvum and C. meleagridis , which gave the same-sized fragments with all the reactions, and C. muris and C. baileyi , which gave positive results with primer pairs targ…
Cryptosporidium parvum: Structural Components of the Oocyst Wall
1999
Cryptosporidium parvum, an enteropathogenic parasite, infects a wide range of mammals including man and constitutes a substantial veterinary and medical threat due to its ubiquitous distribution and the stability of the oocyst stage. The oocyst wall of C. parvum is known to be extremely resistant to chemical and mechanical disruption. Isolated oocyst walls are shown by both thin sectioning and negative staining transmission electron microscopy to possess a filamentous array on the inner surface. This filamentous array can be greatly depleted by digestion with proteinase K and trypsin, but pepsin has less effect. Ultrasonication of the untreated oocyst walls produced almost no fragmentation,…
Presenza di Giardia e Cryptosporidium in reflui civili e in campioni d'acqua superficiale e profonda del territorio palermitano
2005
This paper reports the investigation carried out on the occurrence of Cryptosporidium and Giardia (oo)cysts in water samples of two municipal treatment plants, and in surface water and ground water wells of the province of Palermo. The wastewater samples taken before and after treatment process were assayed over the course of one year Giardia cysts were detected in all samples throught the year at higher concentration levels than Cryptosporidium oocysts, with a peak observed in spring. The overall removal efficiency of (oo)cysts in the treatment plants was about of 90%. Their presence were also searched in surface waters (three artificial lakes and one river); (oo)cysts were detected in one…
Vienšūņa Cryptosporidium spp. izplatība un invāziju veicinošie faktori liellopos Latvijā
2018
Cryptosporidium spp. ir nozīmīgs, diareju izraisošais patogēns, kura invāziju ietekmējoši faktori un ekstensitāte liellopos ir maz pētīti Latvijas teritorijā. Bakalaura darba ietvaros, laika periodā no 2017. gada rudens līdz 2018. gada pavasarim, tika analizēti 135 paraugi no septiņām saimniecībām, četros vēsturiskos Latvijas reģionos (Kurzeme, Zemgale, Latgale, Vidzeme). Visi paraugi tika izmeklēti ar koproloģisko metodi - Cryptosporidium spp. koncentrāciju un sekojošu krāsošanu ar modificēto Ziehl-Neelsen metodi, ar mērķi, noteikt ekstensitāti Latvijas teritorijā un invāziju ietekmējošos faktorus. Katrā no saimniecībām tika veikta informācijas ievākšana par pētāmo dzīvnieku, tā dzīvošanas…
INTESTINAL INFECTION BY CRYPTOSPORIDIUM IN THREE CHILDREN WITH ABDOMINAL PAIN AND CHRONIC DIARRHOEA
1985
Children infection by Cryptosporidium sp. have been communicated since 1976 usually associated to acute diarrohoeal disease. This protozoa has been isolated recently in SIDA patients with serious illness. Three new cases, the first of spanish pediatric literature, are described in this paper. Children were males; two of them twins. Age ranged 24 to 27 m. All lived in Valencia, and went to infant's school with high stand of living and domestic animal relationship. The most frequent symptom was well located colic abdominal pain with day predominance and 2 months of evolution in the twins. The third case began with abdominal pain and discomfort. Three months before had been treated with Metron…
Dynamics of gut mucosal and systemic Th1/Th2 cytokine responses in interferon-gamma and interleukin-12p40 knock out mice during primary and challenge…
2009
Cryptosporidium parvum is an intracellular parasite causing enteritis which can become life-threatening in the immunocompromised host. CD4+ T cells and interferon (IFN)-gamma play dominant roles in host immune response to infection. However, effector mechanisms that are responsible for recovery from infection are poorly understood. In the present study we analyzed mice deficient in IFN-gamma or interleukin (IL)-12 in parallel to C57BL/6 wild type mice as models for murine cryptosporidiosis. Our results identified IFN-gamma as the key cytokine in the innate as well as adaptive immunity during primary and also challenge C. parvum infection. Furthermore, both Th1 and Th2 cytokines appear to co…
A protective role for interleukin 18 in interferon γ-mediated innate immunity to Cryptosporidium parvum that is independent of natural killer cells.
2012
Innate immunity against some intracellular parasitic protozoa involves interleukin 18 (IL-18)-mediated interferon γ (IFN-γ) production by natural killer (NK) cells, but the role of IL-18 in innate resistance to Cryptosporidium infection is unknown. Adult Rag2(-/-)γc(-/-) mice that lack NK cells, T cells, and B cells demonstrated resistance to Cryptosporidium parvum infection that was IFN-γ dependent. Treatment with anti-IL-18-neutralizing antibodies resulted in loss of resistance correlating with reduced intestinal IFN-γ expression. Intestinal mature IL-18 expression increased in vivo during infection and also in the intestinal epithelial cell line CMT-93 following combined IFN-γ treatment/…