Search results for "Biochemical Phenomena"
showing 10 items of 496 documents
Listeria monocytogenes EGD-e biofilms: no mushrooms but a network of knitted chains.
2008
ABSTRACT Listeria monocytogenes is a food pathogen that can attach on most of the surfaces encountered in the food industry. Biofilms are three-dimensional microbial structures that facilitate the persistence of pathogens on surfaces, their resistance toward antimicrobials, and the final contamination of processed goods. So far, little is known about the structural dynamics of L. monocytogenes biofilm formation and its regulation. The aims of this study were, by combining genetics and time-lapse laser-scanning confocal microscopy (LSCM), (i) to characterize the structural dynamics of L. monocytogenes EGD-e sessile growth in two nutritional environments (with or without a nutrient flow), and…
Characterization of the Carbapenem-Hydrolyzing Oxacillinase Oxa-58 in an Acinetobacter Genospecies 3 Clinical Isolate
2008
ABSTRACT Based on imipenem resistance in an Acinetobacter genospecies 3 clinical isolate, we were able to identify, for the first time in this genomic species, a plasmid-encoded bla OXA-58 gene that was 100% homologous to the same gene in Acinetobacter baumannii .
ESBL-producing Klebsiella pneumoniae in a University hospital: Molecular features, diffusion of epidemic clones and evaluation of cross-transmission.
2021
The worldwide spread of Klebsiella pneumoniae producing extended-spectrum β-lactamase (ESBL-Kp) is a significant threat. Specifically, various pandemic clones of ESBL-Kp are involved in hospital outbreaks and caused serious infections. In that context, we assessed the phenotypic and molecular features of a collection of ESBL-Kp isolates in a French university hospital and evaluated the occurrence of potential cross-transmissions. Over a 2-year period (2017–2018), 204 non-duplicate isolates of ESBL-Kp were isolated from clinical (n = 118, 57.8%) or screening (n = 86, 42.2%) sample cultures. These isolates were predominantly resistant to cotrimoxazole (88.8%) and ofloxacin (82.8%) but remaine…
<i>Aeromonas hydrophila</i> subsp. <i>dhakensis</i> Isolated from Feces, Water and Fish in Mediterranean Spain
2012
Eight Aeromonas hydrophila-like arabinose-negative isolates from diverse sources (i.e., river freshwater, cooling-system water pond, diseased wild European eels, and human stools) sampled in Valencia (Spain) during 2004–2005, were characterized by 16S rRNA gene sequencing and extensive biochemical testing along with reference strains of most Aeromonas species. These isolates and all reference strains of A. hydrophila subsp. dhakensis and A. aquariorum showed a 16S rRNA sequence similarity of 99.8–100%, and they all shared an identical phenotype. This matched exactly with that of A. hydrophila subsp. dhakensis since all strains displayed positive responses to the Voges-Prokauer test and to t…
Heavy metal pollution disturbs immune response in wild ant populations
2005
Concern about the effects of environmental contaminants on immune function in both humans and wildlife is growing and practically nothing is known about this impact on terrestrial invertebrates, even though they are known to easily accumulate pollutants. We studied the effect of industrial heavy metal contamination on immune defense of a free-living wood ant (Formica aquilonia). To find out whether ants show an adapted immune function in a polluted environment, we compared encapsulation responses between local and translocated colonies. Local colonies showed higher heavy metal levels than the translocated ones but the encapsulation response was similar between the two groups, indicating tha…
Nanocarriers and immune cells
2019
Nanocarriers (NCs) have a high potential as target-specific drug-delivery system. Especially immune cells are a prime target in the nanoparticle-cell interaction. Uptake into the correct subtype of immune cells is crucial. Therefore uptake processes as well as intracellular processing is of utmost importance. The so-called protein corona heavily affects the interaction with immune cells which can decide the fate of the NC for degradation. On a wider perspective also nanoparticles which were not intentionally made for the transport of drugs get in contact with immune cells e.g. in the lungs. These immune cells are then trying to degrade these foreign materials.
Functional C1-inhibitor diagnostics in hereditary angioedema: Assay evaluation and recommendations
2008
Hereditary angioedema (HAE) is an autosomal dominant disease characterized by recurrent episodes of potentially life-threatening angioedema. The most widespread underlying genetic deficiency is a heterozygous deficiency of the serine protease inhibitor Cl esterase inhibitor (C1-Inh). In addition to low C4 levels, the most important laboratory parameter for correct diagnosis of HAE or angioedema due to acquired C1-Inh deficiency is reduced C1-Inh function (fC1-Inh). No direct recommendations about the assays for fC1-Inh or sample handling conditions are available, although this would prove especially useful when a laboratory first starts to offer assays on fC1-Inh for HAE diagnosis. In the p…
Identification of modifications in microbial, native tRNA that suppress immunostimulatory activity
2012
2′-O-methylation of guanosine 18 is a naturally occurring tRNA modification that can suppress immune TLR7 responses.
Effects of Dextran Sulfate 500 on Cell-Mediated Resistance to Infection with Listeria monocytogenes in Mice.
1974
Injection of dextran sulfate 500 caused loss of antibacterial resistance. Mice became more susceptible to an infection with Listeria monocytogenes and were unable to develop antilisterial immunity after both active and passive immunization with passively administered spleen cells from Listeria -immune donors. Indirect evidence suggests that the phagocytic component of cell-mediated resistance to bacterial infection is the site of attack of dextran sulfate.
Dissection of human papillomavirus type 33 L2 domains involved in nuclear domains (ND) 10 homing and reorganization
2003
Abstract We have recently shown that the minor capsid protein L2 of human papillomavirus type 33 (HPV33) recruits the transcriptional repressor Daxx into nuclear domains (ND) 10 and causes the loss of the transcriptional activator Sp100 from these subnuclear structures (Florin et al., 2002b) . In order to dissect L2 domains involved in nuclear translocation, ND10 homing, loss of Sp100, and recruitment of Daxx, a detailed deletion mutagenesis of L2 was performed. Using immunofluorescence and green fluorescent protein fusions, we have identified two nuclear localization signals (NLS) in the central and C-terminal part of L2, respectively, homologous to previously identified NLS in HPV6B L2 (S…