Search results for "Bacteriology"

Genotypic study of Citrobacter koseri , an emergent platelet contaminant since 2012 in France

2019

International audience; Background: Transfusion-transmitted bacterial infection is a rare occurrence but the most feared complication in transfusion practices. Between 2012 and 2017, five cases of platelet concentrates (PCs) contaminated with the bacterial pathogen Citrobacter koseri (PC-Ck) have been reported in France, with two leading to the death of the recipients. We tested the possibilities of the emergence of a PC-specific clone of C. koseri (Ck) and of specific bacterial genes associated with PC contamination.Study design and methods: The phylogenetic network, based on a homemade Ck core genome scheme, inferred from the genomes of 20 worldwide Ck isolates unrelated to PC contaminati…

Probing a Polar Cluster in the Retinal Binding Pocket of Bacteriorhodopsin by a Chemical Design Approach

2012

Bacteriorhodopsin has a polar cluster of amino acids surrounding the retinal molecule, which is responsible for light harvesting to fuel proton pumping. From our previous studies, we have shown that threonine 90 is the pivotal amino acid in this polar cluster, both functionally and structurally. In an attempt to perform a phenotype rescue, we have chemically designed a retinal analogue molecule to compensate the drastic effects of the T90A mutation in bacteriorhodopsin. This analogue substitutes the methyl group at position C(13) of the retinal hydrocarbon chain by and ethyl group (20-methyl retinal). We have analyzed the effect of reconstituting the wild-type and the T90A mutant apoprotein…

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…

Epidemiology of intra-abdominal infection and sepsis in critically ill patients: "AbSeS", a multinational observational cohort study and ESICM Trials…

2019

Pardo-Oviedo, Juan Mauricio/0000-0003-0084-3449; Lopez-Delgado, Juan Carlos/0000-0003-3324-1129; Corradi, Francesco/0000-0002-5588-2608; De Backer, Daniel/0000-0001-9841-5762; POTA, VINCENZO/0000-0001-9999-3388; Tomescu, Dana/0000-0001-9673-5754; Sabetian, Golnar/0000-0001-8764-2150; Girardis, Massimo/0000-0002-2453-0829; Brazzi, Luca/0000-0001-7059-0622; Leone, Marc/0000-0002-3097-758X; Zabolotskikh, Igor Borisovich/0000-0002-3623-2546; De Lange, Dylan/0000-0002-0191-7270; ALMEKHLAFI, GHALEB A./0000-0002-0323-7025; Elke, Gunnar/0000-0002-4948-1605; Grigoras, Ioana/0000-0001-9412-9574; Czuczwar, Miroslaw/0000-0002-9025-6717; Nora, David/0000-0002-1133-7368; Masjedi, Mansoor/0000-0001-6175-9…

Head and neck squamous cell carcinoma in people living with HIV in France.

2018

Abstract Objectives Head and neck squamous cell carcinoma (HNSCC), mainly due to smoking, is one of the leading causes of cancer deaths. However, an increasing number of tumors – especially oropharyngeal cancer – are reported in non-smokers in association with the human papillomavirus (HPV). As HIV-infected individuals are particularly at risk of HPV-related disease, we aimed to describe the burden of HNSCC in this population. Methods Retrospective chart review of patients from HIV clinics diagnosed with HNSCC between 2004 and 2014. Case patients were defined using the International Classification of Disease for Oncology (3rd edition). Age at HIV diagnosis and time from HIV diagnosis to HNS…

Tuberkulins un tuberkulina reakcijas

1929

Agr system of Listeria monocytogenes EGD-e: role in adherence and differential expression pattern.

2007

ABSTRACT In this study, we investigated the agrBDCA operon in the pathogenic bacterium Listeria monocytogenes EGD-e. In-frame deletion of agrA and agrD resulted in an altered adherence and biofilm formation on abiotic surfaces, suggesting the involvement of the agr system of L. monocytogenes during the early stages of biofilm formation. Real-time PCR experiments indicated that the transcript levels of agrBDCA depended on the stage of biofilm development, since the levels were lower after the initial attachment period than during biofilm growth, whereas transcription during planktonic growth was not growth phase dependent. The mRNA quantification data also suggested that the agr system was a…

Genetics for Pseudoalteromonas provides tools to manipulate marine bacterial virus PM2

2008

ABSTRACT The genetic manipulation of marine double-stranded DNA (dsDNA) bacteriophage PM2 ( Corticoviridae ) has been limited so far. The isolation of an autonomously replicating DNA element of Pseudoalteromonas haloplanktis TAC125 and construction of a shuttle vector replicating in both Escherichia coli and Pseudoalteromonas enabled us to design a set of conjugative shuttle plasmids encoding tRNA suppressors for amber mutations. Using a host strain carrying a suppressor plasmid allows the introduction and analysis of nonsense mutations in PM2. Here, we describe the isolation and characterization of a suppressor-sensitive PM2 sus2 mutant deficient in the structural protein P10. To infect an…

Vezatin, a novel transmembrane protein, bridges myosin VIIA to the cadherin-catenins complex

2000

International audience; Defects in myosin VIIA are responsible for deafness in the human and mouse. The role of this unconventional myosin in the sensory hair cells of the inner ear is not yet understood. Here we show that the C-terminal FERM domain of myosin VIIA binds to a novel transmembrane protein, vezatin, which we identi®ed by a yeast two-hybrid screen. Vezatin is a ubiquitous protein of adherens cell±cell junctions, where it interacts with both myosin VIIA and the cadherin±catenins complex. Its recruitment to adherens junctions implicates the C-terminal region of a-catenin. Taken together, these data suggest that myosin VIIA, anchored by vezatin to the cadherin±catenins complex, cre…

The analysis of the oral DNA virome reveals which viruses are widespread and rare among healthy young adults in Valencia (Spain).

2017

We have analysed oral wash samples from 72 healthy young adults in Valencia (Spain) for a metagenomic analysis through the construction of shotgun libraries and high-throughput-sequencing. The oral viral communities have been taxonomically characterised as well as and the gene content from the latter. The majority of viruses are found in few individuals, with single occurrences being the most widespread ones, whereas universally distributed viruses, while present, are relatively rare, with bacteriophages from families Siphoviridae and Myoviridae, and Streptococcus phages, as well as the eukaryotic viral family Herpesviridae amongst the most widespread viruses. No significant differences wer…