Search results for "Parasitology"
showing 10 items of 1410 documents
Simultaneous infection of cattle with different Anaplasma phagocytophilum variants.
2019
Anaplasma phagocytophilum is a tick-transmitted Gram-negative obligate intracellular bacterium that replicates in neutrophil granulocytes. It causes tick-borne fever in cattle and sheep. We report here the case of a 5-year-old cow from Germany with clinically overt granulocytic anaplasmosis presenting with fever, lower limb oedema and drop in milk-yield. The herd encompassed 10 animals, 8 other animals showed subclinical infection. The strains from the 9 A. phagocytophilum positive cows were molecularly characterized using ankA gene-based and multilocus sequence typing (MLST). Seven of 9 (78%) animals were infected simultaneously with different ankA variants belonging to ankA clusters I and…
Numerous Fasciola plasminogen-binding proteins may underlie blood-brain barrier leakage and explain neurological disorder complexity and heterogeneit…
2019
15 páginas, 5 figuras y 1 tabla
Non-canonical regulation of glutathione and trehalose biosynthesis characterizes non-Saccharomyces wine yeasts with poor performance in active dry ye…
2018
Several yeast species, belonging to Saccharomyces and non-Saccharomyces genera, play fundamental roles during spontaneous must grape fermentation, and recent studies have shown that mixed fermentations, co-inoculated with S. cerevisiae and non-Saccharomyces strains, can improve wine organoleptic properties. During active dry yeast (ADY) production, antioxidant systems play an essential role in yeast survival and vitality as both biomass propagation and dehydration cause cellular oxidative stress and negatively affect technological performance. Mechanisms for adaptation and resistance to desiccation have been described for S. cerevisiae, but no data are available on the physiology and oxidat…
Aggregation patterns of helminth populations in the introduced fish, Liza haematocheilus (Teleostei: Mugilidae): disentangling host–parasite relation…
2018
International audience; A number of hypotheses exist to explain aggregated distributions, but they have seldom been used to investigate differences in parasite spatial distribution between native and introduced hosts. We applied two aggregation models, the negative binomial distribution and Taylor's power law, to study the aggregation patterns of helminth populations from Liza haematocheilus across its native (Sea of Japan) and introduced (Sea of Azov) distribution ranges. In accordance with the enemy release hypothesis, we predicted that parasite populations in the introduced host range would be less aggregated than in the native host area, because aggregation is tightly constrained by abu…
Assembly rules of helminth parasite communities in grey mullets: combining components of diversity.
2020
Abstract Organisms aggregate in ecological communities. It has been widely debated whether these associations are explained by deterministic or, in contrast, random processes. The answer may vary, depending on the level of an organisational scale (α, β and γ) and the facet of diversity considered: taxonomic, functional and phylogenetic. Diversity at the level of a sampling unit (i.e. host individual) is the α diversity; β diversity represents the extent of dissimilarity in diversity among sampling units (within a level of an organisational scale, β1; between levels of an organisational scale, β2); and the total diversity of a system is γ diversity. Thus, the combination of facets and levels…
Plastic and micro-evolutionary responses of a nematode to the host immune environment
2017
9 pages; International audience; Parasitic organisms have to cope with the defences deployed by their hosts and this can be achieved adopting immune evasion strategies or optimal life history traits according to the prevailing pattern of immune-mediated mortality. Parasites often encounter variable immune environments both within and between hosts, promoting the evolution of plastic strategies instead of fixed responses. Here, we explored the plasticity and micro-evolutionary responses of immunomodulatory mechanisms and life history traits to the immune environment provided by the host, using the parasitic nematode Heligmosomoides polygyrus. To test if the parasite responds plastically to t…
Macrofungal diversity and ecology in two Mediterranean forest ecosystems.
2014
The macrofungal species richness and community assemblages in Italian native woodlands of oaks and Carpinus betulus and non-native woodlands of Pinus spp., Cupressus sempervirens and Eucalyptus camaldulensis were examined through the collection of basidiomata and ascomata over 1 year. The sampling in Collestrada (Umbria) and Pizzo Manolfo (Sicily) forests revealed 216 species of macrofungi. The results indicate differences in macromycete richness and diversity patterns between the two sites. The dominant tree species of the two sites were different; thus, the Collestrada forests had higher mycorrhizal species richness, while the Pizzo Manolfo forest had a higher relative number of saprotrop…
Lasiolactols A and B Produced by the Grapevine Fungal Pathogen Lasiodiplodia mediterranea
2016
A strain of Lasiodiplodia mediterranea, a fungus associated with grapevine decline in Sicily, produced several metabolites in liquid medium. Two new dimeric c-lactols, lasiolactols A and B (1 and 2), were characterized as (2S*,3S*,4R*,5R*,20S*,30S*,40R*,50R*)-and (2R*,3S*,4R*,5R*,20R*,30S*,40R*,50R*)-(5-(4-hydroxymethyl-3,5-dimethyl-tetrahydrofuran- 2-yloxy)-2,4-dimethyl-tetrahydro-furan-3-yl]-methanols by IR, 1D-and 2D-NMR, and HR-ESI-MS. Other four metabolites were identified as botryosphaeriodiplodin, (5R)-5-hydroxylasiodiplodin, (-)-(1R, 2R)-jasmonic acid, and (-)-(3S, 4R, 5R)-4-hydroxymethyl-3,5-dimethyldihydro-2-furanone (3 - 6, resp.). The absolute configuration (R) at hydroxylated s…
A New Niche for Anoxygenic Phototrophs as Endoliths
2018
ABSTRACT Anoxygenic phototrophic bacteria (APBs) occur in a wide range of aquatic habitats, from hot springs to freshwater lakes and intertidal microbial mats. Here, we report the discovery of a novel niche for APBs: endoliths within marine littoral carbonates. In a study of 40 locations around Isla de Mona, Puerto Rico, and Menorca, Spain, 16S rRNA high-throughput sequencing of endolithic community DNA revealed the presence of abundant phylotypes potentially belonging to well-known APB clades. An ad hoc phylogenetic classification of these sequences enabled us to refine the assignments more stringently. Even then, all locations contained such putative APBs, often reaching a significant pro…
[How some commensal bacteria would exacerbate colorectal carcinogenesis?].
2016
International audience; The gut microbiota maintains a relationship with its host with strong mutual benefits. Changes in the composition of the intestinal microbiota have been detected in colorectal cancer patients to the extent that it is now considered as a real contributing factor in this pathology. In this review, we focus on three commensal bacterial species, namely Bacteroides fragilis, Fusobacterium nucleatum, and Escherichia coli, which seem to emerge as pathogens and to contribute to colorectal carcinogenesis through their inflammatory and oncogenic properties.; Le microbiote intestinal entretient une relation mutualiste forte avec l’hôte. Depuis la mise en évidence de modificatio…