Search results for "bacterial"
showing 10 items of 3246 documents
Pyrosequencing survey of intestinal microbiota diversity in cultured sea bass (Dicentrarchus labrax) fed functional diets.
2014
The routine use of chemotherapy to control bacterial diseases in aquatic populations has resulted in the development and spread of antibiotic resistance. The inclusion of immunostimulants in fish diets (functional diets) is one of the main strategies to solve this threat. This study aimed to analyse the intestinal microbiota of cultured European sea bass (Dicentrarchus labrax) fed two functional diets applying pyrosequencing of PCR-amplified 16S rRNA gene. Quality-filtered reads were assigned to family and genus taxonomic levels using the Ribosomal Database Project classifier. The autochthonous intestinal microbiota of sea bass consisted of two dominant bacterial genera: Dysgonomonas (Bacte…
Exploiting the Redox Activity of MIL-100(Fe) Carrier Enables Prolonged Carvacrol Antimicrobial Activity
2022
The design of efficient food contact materials that maintain optimal levels of food safety is of paramount relevance to reduce the increasing number of foodborne illnesses. In this work, we develop a smart composite metal-organic framework (MOF)-based material that fosters a unique prolonged antibacterial activity. The composite is obtained by entrapping a natural food preserving molecule, carvacrol, into a mesoporous MIL-100(Fe) material following a direct and biocompatible impregnation method, and obtaining particularly high payloads. By exploiting the intrinsic redox nature of the MIL-100(Fe) material, it is possible to achieve a prolonged activity against Escherichia coli and Listeria i…
The L-tartrate/succinate antiporter TtdT (YgjE) of L-tartrate fermentation in Escherichia coli.
2007
ABSTRACT Escherichia coli ferments l -tartrate under anaerobic conditions in the presence of an additional electron donor to succinate. The carrier for l -tartrate uptake and succinate export and its relation to the general C 4 -dicarboxylate carriers DcuA, DcuB, and DcuC were studied. The secondary carrier TtdT, encoded by the ttdT (previously called ygjE ) gene, is required for the uptake of l -tartrate. The ttdT gene is located downstream of the ttdA and ttdB genes, encoding the l -tartrate dehydratase TtdAB. Analysis of mRNA by reverse transcription-PCR showed that ttdA , ttdB , and ttdT are cotranscribed. Deletion of ttdT abolished growth by l -tartrate and degradation of l -tartrate c…
Seeking the Source of Catalytic Efficiency of Lindane Dehydrochlorinase, LinA.
2020
Herein we present the results of an in-depth simulation study of LinA and its two variants. In our analysis, we combined the exploration of protein conformational dynamics with and without bound substrates (hexachlorocyclohexane (HCH) isomers) performed using molecular dynamics simulation followed by the extraction of the most frequently visited conformations and their characteristics with a detailed description of the interactions taking place in the active site between the respective HCH molecule and the first shell residues by using symmetry-adapted perturbation theory (SAPT) calculations. A detailed investigation of the conformational space of LinA substates has been accompanied by desc…
Insecticidal Activity of Strains of Bacillus thuringiensis on Larvae and Adults of Bactrocera oleae Gmelin (Dipt. Tephritidae)
1999
The olive fly, Bactrocera oleae, is the key pest on olives in the Mediterranean area. The pest can destroy, in some cases, up to 70% of the olive production. Its control relies mainly on chemical treatments, sometimes applied by aircraft over vast areas, with their subsequent ecological and toxicological side effects. Bacillus thuringiensis is a spore-forming soil bacterium which produces a protein crystal toxic to some insects, including the orders of Lepidoptera, Diptera, and Coleoptera and other invertebrates. The aim of this study was to search for isolates toxic to B. oleae. Several hundred B. thuringiensis isolates were obtained from olive groves and olive presses in different areas o…
A comparison of infestation patterns by Ixodes ticks in urban and rural populations of the Common Blackbird Turdus merula
2002
Although spatial variation in the patterns of parasite infestations among host populations may have important ecological and epidemiological consequences, the causes underlying such variation are poorly known. In the context of a long-term study on the population biology of Common Blackbirds Turdus merula , we examined the prevalence and intensity of infestation by Ixodes ticks between birds living in rural vs. urban habitats. The overall prevalence of tick infestations was significantly higher in the rural habitat where 74% of individuals ( n = 130) were infested. This result contrasted markedly with the situation in the urban habitat where less than 2% of individuals ( n = 360) carried ti…
Volatile components ofCentaurea cineraria L. subsp.umbrosa (Lacaita) Pign. andCentaurea napifolia L. (Asteraceae), two species growing wild in Sicily
2003
The volatile components of the flowerheads of Centaurea cineraria L. subsp. umbrosa (Lacaita) Pign. and Centaurea napifolia L. were obtained by hydrodistillation and identified by GC and GC-MS. Altogether 55 components were identified, mostly sesquiterpenes and hydrocarbons. Copyright © 2003 John Wiley & Sons, Ltd.
Kinetic Characterization of Secretory Transport of a New Ciprofloxacin Derivative (CNV97100) across Caco-2 Cell Monolayers**This work has been submit…
2002
The kinetics of transport of a new fluoroquinolone antibiotic (CNV97100) and its analogs were characterized using the Caco-2 cell culture model. Unidirectional permeabilities of these analogs were greater (p < 0.05) than that of ciprofloxacin. The absorptive permeabilities (P(AB)) of 4'-N-substituted analogs (CNV97101-104) were 400-600% greater, whereas the secretory permeability (P(BA)) was 25-80% greater than unsubstituted analogs because CNV97101-104 were poor substrates for efflux transporters (efflux ratio approximately 1). The transport of compounds without 4'-N-substitution (i.e., ciprofloxacin and CNV97100) favored secretion (efflux ratio approximately 4). Further characterization o…
Composition and Antimicrobial Activity of Essential Oil ofAnthemis tenuisectaBall
2007
Abstract The Chemical composition of the essential oil of Anthemis tenuisecta Ball. (Anthemideae) was analyzed by gas Chromatography-mass spectrometry (GC-MS). Forty eight components accounting for 89.5 % of the oil were identified, being camphor (17.5 %), 6-methyl-5-hepten-2-one (17.1 %), borneol (11.5 %), sesquicineole (11%) and camphene (5.7 %) the main compounds. In the antibacterial diffusion assay, the oil showed activity against Gram-positive bacteria.
Composition and Antibacterial Activity of Essential Oils ofCladanthus arabicusCass. (Asteraceae)
2005
Abstract The chemical composition of the essential oils of the aerial parts (stems and leaves: sample A) and flowers (sample B) of Cladanthus arabicus Cass., were analysed by GC-MS. Monoterpenes hydrocarbons constituted the main chemical group in both essential oils, with Sabinene, β-pinene, α-pinene, myrcene, α-phellandrene and p-cymene as the main compounds. Sample A was tested for its antimicrobial activity against six Gram positive and negative bacteria. Results showed that the oil exhibited a significant antibacterial activity.