Search results for "BACTERIA"
showing 10 items of 4919 documents
Immunity and Virulence in Bird-Parasite Interactions.
2010
8 pages; International audience; The interaction between hosts and parasites is characterized by the evolution of reciproca adaptations aiming at reducing the cost of infection (from the host point of view) and to optimize host exploitation (from the parasite point of view). Within this co-evolutionary scenario, the immune system takes a central role. The immune system has evolved to fight off parasitic attacks. However, immune defences cannot be deployed without costs which set a limit to the protective effect of immunity. Moreover, immune defences impose strong selection pressures on the parasite and can favour the evolution of more virulent pathogen strains. In this article, we will disc…
Interpreting immunological indices: the importance of taking parasite community into account. An example in blackbirds Turdus merula.
2015
13 pages; International audience; Despite the intensive use of immune indices in immunoecology, whether to interpret the results of immune indices in terms of actual immune competence (i.e. ability to control and clear parasite infections as indicated by high values of immune indices associated with low parasite loads) or current immune activation (pathogenic infection being associated with high parasite load and high values of immune indices) is still an open question. Most studies to date have produced contrasting results focused on the effect of a single parasite species despite the fact that hosts usually harbour a community of parasites that influences one another's impact on host immu…
Characterization of the biodegradation, bioremediation and detoxification capacity of a bacterial consortium able to degrade the fungicide thiabendaz…
2017
Thiabendazole (TBZ) is a persistent fungicide used in the post-harvest treatment of fruits. Its application results in the production of contaminated effluents which should be treated before their environmental discharge. In the absence of efficient treatment methods in place, biological systems based on microbial inocula with specialized degrading capacities against TBZ could be a feasible treatment approach. Only recently the first bacterial consortium able to rapidly transform TBZ was isolated. This study aimed to characterize its biodegradation, bioremediation and detoxification potential. The capacity of the consortium to mineralize 14C-benzyl-ring labelled TBZ was initially assessed. …
Pseudomonas salomonii sp. nov., pathogenic on garlic, and Pseudomonas palleroniara sp. nov., isolated from rice
2002
International audience; A total of 26 strains, including 15 strains isolated from garlic plants with the typical symptoms of 'Café au lait' disease and 11 strains isolated from diseased or healthy rice seeds and sheaths infested by Pseudomonas fuscovaginae, were compared with 70 type or reference strains of oxidase-positive pathogenic or non-pathogenic fluorescent pseudomonads. The strains were characterized by using a polyphasic taxonomic approach. Numerical taxonomy of phenotypic characteristics showed that the garlic and rice strains were related to each other. However, they clustered into separate phenons, distinct from those of the other strains tested, and were different in several nu…
Detection and Characterization of Wolbachia Infections in Natural Populations of Aphids: Is the Hidden Diversity Fully Unraveled?
2011
Copyright © 2011 Augustinos et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Aphids are a serious threat to agriculture, despite being a rather small group of insects. The about 4,000 species worldwide engage in highly interesting and complex relationships with their microbial fauna. One of the key symbionts in arthropods is Wolbachia, an a-Proteobacterium implicated in many important biological processes and believed to be a potential tool for biological control. Aphids were thought not to harbour W…
The beneficial rhizosphere : a necessary strategy for microplant production
2000
Society's expectation that plant production systems will become more compatible with the environment requires the development of an agriculture with low chemical inputs. With microplants, this can be achieved successfully by the introduction of beneficial microorganisms, particularly those developing in the rhizosphere. Inoculation with mycorrhizal fungi has provided a wide range of examples of the usefulness of this technology. Recent results indicate that this application could be improved by combining mycorrhizal inoculation with other soil microbes with complementary beneficial effects. It is proposed that multimicrobial biotization is a valuable development for microplant technology.
Evolutionary Changes after Translational Challenges Imposed by Horizontal Gene Transfer
2019
International audience; Genes acquired by horizontal gene transfer (HGT) may provide the recipient organism with potentially new functions, but proper expression level and integration of the transferred genes in the novel environment are not granted. Notably, transferred genes can differ from the receiving genome in codon usage preferences, leading to impaired translation and reduced functionality. Here, we characterize the genomic and proteomic changes undergone during experimental evolution of Escherichia coli after HGT of three synonymous versions, presenting very different codon usage preference, of an antibiotic resistance gene. The experimental evolution was conducted with and without…
Antibiofilm activity of coriander (Coriander sativum L.) grown in Argentina against food contaminants and human pathogenic bacteria
2020
Abstract Bacterial spoilage of food and other infections are a coordinated mechanism controlled by quorum sensing (QS), which regulate the expression of virulence factors, such as biofilm. The antimicrobial, antibiofilm, anti-QS and anti-swarming properties of hexane (HE), chloroform (CE), ethyl acetate (EAE), methanolic (ME) and total methanolic (TME) extracts of coriander grown in Argentina were investigated. In vivo extracts toxicity using Galleria mellonella L. model and chemical composition (GC-MS) were also assessed. The antibiofilm activity of polystyrene surfaces coated with the most active extracts was evaluated. At non-inhibitory growth concentrations, extracts showed a strong ant…
Applying the Anna Karenina principle for wild animal gut microbiota: Temporal stability of the bank vole gut microbiota in a disturbed environment.
2020
Gut microbiota play an important role in host health. Yet, the drivers and patterns of microbiota imbalance (dysbiosis) in wild animals remain largely unexplored. One hypothesised outcome of stress on animal microbiomes is a destabilised microbial community that is characterised by an increase in inter-individual differences compared with microbiomes of healthy animals, which are expected to be (a) temporally stable and (b) relatively similar among individuals. This set of predictions for response of microbiomes to stressors is known as the Anna Karenina principle (AKP) for animal microbiomes. We examine the AKP in a wild mammal inhabiting disturbed environments by conducting a capture-mark…
Biopreservation of tomatoes using fermented media by lactic acid bacteria
2020
Abstract Post-harvest spoilage fungi in tomatoes represent an economic loss for industry and consumers. There is currently an increasing demand for novel applications of bio-preservatives as replacers of chemical additives and pesticides in food. In this study, nine lactic acid bacteria strains isolated from tomato and sourdough were screened for antifungal activity in vitro against 33 fungal strains and used as bio-preservatives of tomato inoculated with Penicillium expansum and Aspergillus flavus. The identification of the compounds potentially responsible for the antifungal activity, such as organic acids, phenolic acids and volatile organic compounds (VOCs), were identified and quantifi…