Search results for "Bacteria"
showing 10 items of 4919 documents
A rhamnose-binding lectin from sea bass (Dicentrarchus labrax) plasma agglutinates and opsonizes pathogenic bacteria
2014
Abstract The discovery of rhamnose-binding lectins (RBLs) in teleost fish eggs led to the identification of a novel lectin family characterized by a unique sequence motif and a structural fold, and initially proposed to modulate fertilization. Further studies of the RBL tissue localization and gene organization were also suggestive of role(s) in innate immunity. Here we describe the purification, and biochemical and functional characterization of a novel RBL (DlRBL) from sea bass (Dicentrarchus labrax) serum. The purified DlRBL had electrophoretic mobilities corresponding to 24 kDa and 100 kDa under reducing and non-reducing conditions, respectively, suggesting that in plasma the DlRBL is p…
Purification and characterisation of a plasmin-sensitive surface protein of Staphylococcus aureus.
1996
Certain methicillin-resistant Staphylococcus aureus strains contain a 230-kDa cell-wall protein which is not present on the surface of other staphylococci. The presence of this 230-kDa protein is associated with a negative test result in commercial assays designed to detect fibrinogen-binding proteins and/or protein A on the staphylococcal surface. We have purified and partially characterised the 230-kDa protein from a lysostaphin digest of a non-agglutinating methicillin-resistant S. aureus strain. Partial amino acid sequence data obtained from the purified protein did not reveal any significant similarities to known proteins which indicates that the protein is novel. The 230-kDa protein w…
Necrotizing fasciitis of the face: A life-threatening condition
2009
Necrotizing fasciitis (NF) is a highly aggressive infectious process, polymicrobial in nature, involving soft tissues with a high risk of rapid spread through superficial and deep fascial planes and muscular layers. Cervical NF is quite rare, is mostly of odontogenic origin, and may be complicated by descendant mediastinitis with a very high mortality rate. Systemic conditions impairing the patient's immune competence, such as diabetes, may play a predisposing role. An effective treatment strategy includes prompt diagnosis (clinical findings, local microbiological tests, blood culture and, if deemed necessary, histopathology), broad-spectrum antibiotic therapy as early as possible which sho…
Shared midgut binding sites for Cry1A.105, Cry1Aa, Cry1Ab, Cry1Ac and Cry1Fa proteins from Bacillus thuringiensis in two important corn pests, Ostrin…
2013
First generation of insect-protected transgenic corn (Bt-corn) was based on the expression of Cry1Ab or Cry1Fa proteins. Currently, the trend is the combination of two or more genes expressing proteins that bind to different targets. In addition to broadening the spectrum of action, this strategy helps to delay the evolution of resistance in exposed insect populations. One of such examples is the combination of Cry1A.105 with Cry1Fa and Cry2Ab to control O. nubilalis and S. frugiperda. Cry1A.105 is a chimeric protein with domains I and II and the C-terminal half of the protein from Cry1Ac, and domain III almost identical to Cry1Fa. The aim of the present study was to determine whether the c…
Agricultural management affects the response of soil bacterial community structure and respiration to water-stress
2013
International audience; Soil microorganisms are responsible for organic matter decomposition processes that regulate soil carbon storage and mineralisation to CO2. Climate change is predicted to increase the frequency of drought events, with uncertain consequences for soil microbial communities. In this study we tested the hypothesis that agricultural management used to enhance soil carbon stocks would increase the stability of microbial community structure and activity in response to water-stress. Soil was sampled from a long-term field trial with three soil carbon management systems and was used in a laboratory study of the effect of a dry wet cycle on organic C mineralisation and microbi…
Intermittent operation of UASB reactors treating wastewater polluted with organic solvents: process performance and microbial community evaluation
2019
The effect of intermittent feeding on the treatment of wastewater polluted with ethanol, ethyl acetate and 1-ethoxy-2-propanol in anaerobic upflow sludge blanket reactors was investigated. Three laboratory-scale reactors, one periodically supplemented with chitosan, were operated in an intermittent pattern (16 hours per day; 5 days per week) during 5 months. Removal efficiencies higher than 94% were obtained at organic loading rates up to 50 kg COD m−3 d−1. The addition of chitosan positively affected the specific methanogenic activity of the granular sludge. Although partial deterioration of the granules was observed, it was not correlated with variations in the production of extracellular…
[Legionella spp. contamination in indoor air: preliminary results of an Italian multicenter study].
2014
Obiettivo. Rilevare la presenza di Legionella spp. nell’aria attraverso un protocollo standardizzato, a fianco dei tradizionali metodi impiegati per la rete idrica. Disegno. In dieci strutture sanitarie è stato selezionato un bagno, la cui acqua presentava una contaminazione da Legionella >1.000 unità formanti colonie (ufc)/litro. La contaminazione dell’aria è stata valutata tramite campionamento attivo (Surface Air System, SAS) e passivo, impiegando piastre di sedimentazione per la valutazione dell’Indice Microbico Aria (Index of Microbial Air, IMA). I campionamenti sono stati effettuati per 8 ore consecutive, a circa 1 m dal pavimento e a 50 cm dal rubinetto. Con il campionamento attivo, …
Isolation and characterization of hydrocarbonoclastic bacteria from Algerian coast
2017
Backgrounds The contamination of marine environments by hydrocarbons represents a global concern with consequences on ecosystems and human health. The removal of HC by physical and/or chemical methods is expensive and disrespectful of the environment. The use of HC degrading bacteria is a good alternative for environmental remediation (bioremediation). Objectives The Algerian coastline is exposed to several types of pollutions, including hydrocarbons. The aim was to explore the bioremediation potential of its contaminated harbors for the first time. Methods To identify the hydrocarbon degrading bacteria seawater samples were collected in Sidi fredj harbor (Algeria) and used to enrichment cu…
Preferential localization of Lactococcus lactis cells entrapped in a caseinate/alginate phase separated system.
2013
International audience; This study aimed to entrap bioprotective lactic acid bacteria in a sodium caseinate/sodium alginate aqueous two-phase system. Phase diagram at pH = 7 showed that sodium alginate and sodium caseinate were not miscible when their concentrations exceeded 1% (w/w) and 6% (w/w), respectively. The stability of the caseinate/alginate two-phase system was also checked at pH values of 6.0 and 5.5. Lactococcus lactis subsp. lactis LAB3 cells were added in a 4% (w/w) caseinate/1.5% (w/w) alginate two-phase system at pH = 7. Fluorescence microscopy allowed to observe that the caseinate-rich phase formed droplets dispersed in a continuous alginate-rich phase. The distribution of …
Structure-Function Relationship of Substituted Bromomethylcoumarins in Nucleoside Specificity of RNA Alkylation
2013
Selective alkylation of RNA nucleotides is an important field of RNA biochemistry, e.g. in applications of fluorescent labeling or in structural probing experiments, yet detailed structure-function studies of labeling agents are rare. Here, bromomethylcoumarins as reactive compounds for fluorescent labeling of RNA are developed as an attractive scaffold on which electronic properties can be modulated by varying the substituents. Six different 4-bromomethyl-coumarins of various substitution patterns were tested for nucleotide specificity of RNA alkylation using tRNA from Escherichia coli as substrate. Using semi-quantitative LC-MS/MS analysis, reactions at mildly acidic and slightly alkaline…