Search results for "INFECTIOUS"
showing 10 items of 2953 documents
Parsimonious Scenario for the Emergence of Viroid-Like Replicons De Novo
2019
This article belongs to the Special Issue Viroid-2018: International Conference on Viroids and Viroid-Like RNAs. Viroids are small, non-coding, circular RNA molecules that infect plants. Different hypotheses for their evolutionary origin have been put forward, such as an early emergence in a precellular RNA World or several de novo independent evolutionary origins in plants. Here, we discuss the plausibility of de novo emergence of viroid-like replicons by giving theoretical support to the likelihood of different steps along a parsimonious evolutionary pathway. While Avsunviroidae-like structures are relatively easy to obtain through evolution of a population of random RNA sequences of fixe…
Antipoxvirus Activity Evaluation of Optimized Corroles Based on Development of Autofluorescent ANCHOR Myxoma Virus
2021
International audience; A series of 43 antiviral corrole-based molecules have been tested on myxoma virus (Lausanne-like T1MYXV strain). An autofluorescent MYXV, with an ANCHOR cassette, has been used for the studies. A(2)B-fluorocorroles display various toxicities, from 40 being very toxic (CC50 = 1.7 mu M) to nontoxic 38 (CC50 > 50 mu M), whereas A(3)-fluorocorroles, with one to three fluorine atoms, are not toxic (with the exception of corroles 9, 10, and 22). In vitro, these compounds show a good selectivity index when used alone. Corrole 35 seems to be the most promising compound, which displays a high selectivity index with the lowest IC50. Interestingly, this "Hit" corrole is easy to…
Milker's nodule: an occupational infection and threat to the immunocompromised
2017
Milker's nodule virus, also called paravaccinia virus is a DNA virus of the parapoxvirus genus transmitted from infected cows to humans. It results from contact with cattle, cattle byproducts, or fomites. Classified as an occupational disorder, those at risk of exposure include farmers, butchers, and agricultural tourists. The viral infection begins 5-15 days after inoculation as an erythematous-purple, round nodule with a clear depressed center, and a surrounding erythematous ring. While familiar to those in farming communities, the presence of the nodule may be concerning to others, particularly the immunosuppressed. Milker's nodules are self-limited in immunocompetent individuals and hea…
Ubiquitous giants: a plethora of giant viruses found in Brazil and Antarctica
2018
Background Since the discovery of giant viruses infecting amoebae in 2003, many dogmas of virology have been revised and the search for these viruses has been intensified. Over the last few years, several new groups of these viruses have been discovered in various types of samples and environments.In this work, we describe the isolation of 68 giant viruses of amoeba obtained from environmental samples from Brazil and Antarctica. Methods Isolated viruses were identified by hemacolor staining, PCR assays and electron microscopy (scanning and/or transmission). Results A total of 64 viruses belonging to the Mimiviridae family were isolated (26 from lineage A, 13 from lineage B, 2 from lineage C…
Development of a New Antileishmanial Aziridine-2,3-Dicarboxylate-Based Inhibitor with High Selectivity for Parasite Cysteine Proteases
2015
ABSTRACT Leishmaniasis is one of the major neglected tropical diseases of the world. Druggable targets are the parasite cysteine proteases (CPs) of clan CA, family C1 (CAC1). In previous studies, we identified two peptidomimetic compounds, the aziridine-2,3-dicarboxylate compounds 13b and 13e, in a series of inhibitors of the cathepsin L (CL) subfamily of the papain clan CAC1. Both displayed antileishmanial activity in vitro while not showing cytotoxicity against host cells. In further investigations, the mode of action was characterized in Leishmania major . It was demonstrated that aziridines 13b and 13e mainly inhibited the parasitic cathepsin B (CB)-like CPC enzyme and, additionally, ma…
Host Cell Calpains Can Cleave Structural Proteins from the Enterovirus Polyprotein
2019
Enteroviruses are small RNA viruses that cause diseases with various symptoms ranging from mild to severe. Enterovirus proteins are translated as a single polyprotein, which is cleaved by viral proteases to release capsid and nonstructural proteins. Here, we show that also cellular calpains have a potential role in the processing of the enteroviral polyprotein. Using purified calpains 1 and 2 in an in vitro assay, we show that addition of calpains leads to an increase in the release of VP1 and VP3 capsid proteins from P1 of enterovirus B species, detected by western blotting. This was prevented with a calpain inhibitor and was dependent on optimal calcium concentration, especially for calpa…
Parasites Dampen Dendritic Cell Activation to Ensure Their Survival
2017
Dendritic cells (DCs) are critical for induction of protective immunity against Leishmania major. However, DC activation occurs only several weeks after parasite transmission. Parasites synthesize a macrophage-inducible C-type lectin (Mincle) ligand. Engagement of Mincle by the parasite ligand dampens DC activation, thus delaying induction of interferon-γ-producing T cells responsible for parasite eradication.
Chaperoning the Mononegavirales: Current Knowledge and Future Directions
2018
This article belongs to the Special Issue Breakthroughs in Viral Replication.
Lethal systemic and brain infection caused by Prototheca zopfii algae in a patient with acute myeloid leukemia
2021
Systemic protothecosis is an exceptionally rare cause of sepsis with few available therapeutic options. Here, we report on a female patient with newly diagnosed acute myeloid leukemia who died after start of chemotherapy due to a severe septic shock caused by a disseminated systemic infection with Prototheca zopfii including encephalitis.
Innovative Approaches Using Lichen Enriched Media to Improve Isolation and Culturability of Lichen Associated Bacteria
2016
Lichens, self-supporting mutualistic associations between a fungal partner and one or more photosynthetic partners, also harbor non-photosynthetic bacteria. The diversity and contribution of these bacteria to the functioning of lichen symbiosis have recently begun to be studied, often by culture-independent techniques due to difficulties in their isolation and culture. However, culturing as yet unculturable lichenic bacteria is critical to unravel their potential functional roles in lichen symbiogenesis, to explore and exploit their biotechnological potential and for the description of new taxa. Our objective was to improve the recovery of lichen associated bacteria by developing novel isol…