Search results for "Protozoan"
showing 10 items of 135 documents
Secreted proteophosphoglycan of Leishmania mexicana amastigotes activates complement by triggering the mannan binding lectin pathway.
1997
Cutaneous lesions induced by infection of mice with the protozoan parasite, Leishmania mexicana, contain abundant amounts of a high molecular mass proteophosphoglycan (PPG), which is secreted by the amastigote stage residing in phagolysosomes of macrophages and can then be released into the tissue upon rupture of the infected cells. Amastigote PPG forms sausage-shaped but soluble particles and belongs to a novel class of serine-rich proteins that are extensively O-glycosylated by phosphooligosaccharides capped by mannooligosaccharides. The purified molecule is shown here to efficiently activate complement (C) and deplete hemolytic activity of normal serum and may prevent the opsonization of…
High-throughput screening with the Eimeria tenella CDC2-related kinase2/cyclin complex EtCRK2/EtCYC3a
2012
The poultry disease coccidiosis, caused by infection with Eimeria spp. apicomplexan parasites, is responsible for enormous economic losses to the global poultry industry. The rapid increase of resistance to therapeutic agents, as well as the expense of vaccination with live attenuated vaccines, requires the development of new effective treatments for coccidiosis. Because of their key regulatory function in the eukaryotic cell cycle, cyclin-dependent kinases (CDKs) are prominent drug targets. The Eimeria tenella CDC2-related kinase 2 (EtCRK2) is a validated drug target that can be activated in vitro by the CDK activator XlRINGO (Xenopus laevis rapid inducer of G2/M progression in oocytes). B…
Morphology and in vitro infectivity of sporozoites of Cryptosporidium parvum.
2009
An important obstacle in studying Cryptosporidium parvum is the lack of a permanent in vitro cultivation system of the parasite. While short-term cultures using various host cell lines have been widely employed, long-term cultures that would facilitate the immortalization of C. parvum isolates have not yet been developed. The description of the complete development of C. parvum in cell-free culture in 2004 has been received with great interest and also with some astonishment. Unfortunately, attempts to reproduce these results with different isolates of C. parvum and also C. hominis have failed. In this report, we provide an alternative interpretation of the nature of a parasite stage that o…
Recurrent leishmaniasis in kidney transplant recipients: Report of 2 cases and systematic review of the literature
2011
The characteristics of 8 episodes of leishmaniasis with atypical manifestations in 2 Italian kidney transplant recipients are analyzed and contextualized among those of 52 other episodes of leishmaniasis observed in 19 transplant recipients found through a systematic review of the international literature. In all the patients, the initial episode was visceral leishmaniasis, which was associated with mucocutaneous involvement in 2 cases. With the exception of 1 case of post kala-azar dermal leishmaniasis, 2 episodes of Leishmania endophthalmitis, and 3 episodes of mucocutaneous leishmaniasis, all the recurrences were characterized by visceral involvement. The potential role of polymerase cha…
Identification of Cpgp40/15 Type Ib as the Predominant Allele in Isolates of Cryptosporidium spp. from a Waterborne Outbreak of Gastroenteritis in So…
2006
ABSTRACT Cryptosporidium sp. isolates from a waterborne outbreak of diarrhea in France were analyzed by PCR-restriction fragment length polymorphism analysis and sequencing of the Cpgp40/15 locus. Ninety-one percent of the isolates were Cryptosporidium hominis type Ib. The results of this study and those of studies of other outbreaks suggest that the type Ib allele is the predominant allele associated with waterborne cryptosporidiosis.
Toxoplasma gondii seroprevalence varies by cat breed.
2017
Toxoplasma gondii is a widespread zoonotic parasite that is relevant for veterinary and public health. The domestic cat, the definitive host species with the largest worldwide population, has become evolutionarily and epidemiologically the most important host of T. gondii. The outcome of T. gondii infection is influenced by congenital and acquired host characteristics. We detected differences in T. gondii seroprevalence by cat breed in our previous studies. The aims of this study were to estimate T. gondii seroprevalence in selected domestic cat breeds, and to evaluate whether being of a certain breed is associated with T. gondii seropositivity, when the age and lifestyle of the cat are tak…
Comparison of loop-mediated isothermal amplification (LAMP) and PCR for the diagnosis of infection with Trypanosoma brucei ssp. in equids in The Gamb…
2020
Introduction:\ud Infection of equids with Trypanosoma brucei (T. brucei) ssp. is of socioeconomic importance across sub-Saharan Africa as the disease often progresses to cause fatal meningoencephalitis. Loop-mediated isothermal amplification (LAMP) has been developed as a cost-effective molecular diagnostic test and is potentially applicable for use in field-based laboratories.\ud \ud Part I:\ud Threshold levels for T. brucei ssp. detection by LAMP were determined using whole equine blood specimens spiked with known concentrations of parasites. Results were compared to OIE antemortem gold standard of T. brucei-PCR (TBR-PCR).\ud \ud Results I:\ud Threshold for detection of T. brucei ssp. on …
In vivo and in vitro cytokine profiles and mononuclear cell subsets in sicilian patients with active visceral leishmaniasis
1995
Sera from Sicilian patients with confirmed visceral leishmaniasis (Leishmania donovani infantum) were analysed at the moment of the diagnosis, during the course of the disease and after clinical recovery, for the concentration of IL-10, IFN-gamma, IL-4 and IL-2. The results show high concentrations of IL-10 and IFN-gamma in the sera at the beginning of infection that return to the normal range following successful chemotherapy. By contrast, PBMC stimulated in vitro with Ag and mitogen produced low levels of IL-10 and IFN-gamma when collected at the time of the diagnosis and normal levels when assayed after recovery. IL-2 was undetected in the sera and was significantly reduced in the supern…
Computer-guided drug repurposing: Identification of trypanocidal activity of clofazimine, benidipine and saquinavir
2015
In spite of remarkable advances in the knowledge on Trypanosoma cruzi biology, no medications to treat Chagas disease have been approved in the last 40 years and almost 8 million people remain infected. Since the public sector and non-profit organizations play a significant role in the research efforts on Chagas disease, it is important to implement research strategies that promote translation of basic research into the clinical practice. Recent international public-private initiatives address the potential of drug repositioning (i.e. finding second or further medical uses for known-medications) which can substantially improve the success at clinical trials and the innovation in the pharmac…
Epidemiology of Toxoplasma and CMV serology and of GBS colonization in pregnancy and neonatal outcome in a Sicilian population
2013
Background: Aim of our study is to analyze the immunological status in pregnancy for two main TORCH agents, Toxoplasma and Cytomegalovirus (CMV), and the results of group B streptococcus (GBS) screening, assessing the risk for congenital infection in a population from Palermo, Italy. Methods: We retrospectively analyzed the medical records of all inborn live newborns who were born in our division during 2012, gathering information about the mother, the pregnancy and neonatal hospitalization at birth. Whenever data were available, we categorized the serologic status of the mothers for Toxoplasma and CMV. We also considered the results of rectal and vaginal swabs for GBS. We compared the resu…