Complete Genome Sequence of Crohn's Disease-Associated Adherent-Invasive E. coli Strain LF82

International audienceBACKGROUND: Ileal lesions of Crohn's disease (CD) patients are abnormally colonized by pathogenic adherent-invasive Escherichia coli (AIEC) able to invade and to replicate within intestinal epithelial cells and macrophages. PRINCIPAL FINDINGS: We report here the complete genome sequence of E. coli LF82, the reference strain of adherent-invasive E. coli associated with ileal Crohn's disease. The LF82 genome of 4,881,487 bp total size contains a circular chromosome with a size of 4,773,108 bp and a plasmid of 108,379 bp. The analysis of predicted coding sequences (CDSs) within the LF82 flexible genome indicated that this genome is close to the avian pathogenic strain APEC_01, meningitis-associated strain S88 and urinary-isolated strain UTI89 with regards to flexible genome and single nucleotide polymorphisms in various virulence factors. Interestingly, we observed that strains LF82 and UTI89 adhered at a similar level to Intestine-407 cells and that like LF82, APEC_01 and UTI89 were highly invasive. However, A1EC strain LF82 had an intermediate killer phenotype compared to APEC-01 and UTI89 and the LF82 genome does not harbour most of specific virulence genes from ExPEC. LF82 genome has evolved from those of ExPEC B2 strains by the acquisition of Salmonella and Yersinia isolated or clustered genes or CDSs located on pLF82 plasmid and at various loci on the chromosome. CONCLUSION: LF82 genome analysis indicated that a number of genes, gene clusters and pathoadaptative mutations which have been acquired may play a role in virulence of AIEC strain LF82

”Cage” metal-organic nanoparticles: applications to treat infections

International audienc

”Cage” metal-organic nanoparticles: applications to treat infections

International audienc

”Cage” metal-organic nanoparticles: applications to treat infections

International audienc

A “green” strategy to construct non-covalent, stable and bioactive coatings on porous MOF nanoparticles

AbstractNanoparticles made of metal-organic frameworks (nanoMOFs) attract a growing interest in gas storage, separation, catalysis, sensing and more recently, biomedicine. Achieving stable, versatile coatings on highly porous nanoMOFs without altering their ability to adsorb molecules of interest represents today a major challenge. Here we bring the proof of concept that the outer surface of porous nanoMOFs can be specifically functionalized in a rapid, biofriendly and non-covalent manner, leading to stable and versatile coatings. Cyclodextrin molecules bearing strong iron complexing groups (phosphates) were firmly anchored to the nanoMOFs' surface, within only a few minutes, simply by incubation with aqueous nanoMOF suspensions. The coating procedure did not affect the nanoMOF porosity, crystallinity, adsorption and release abilities. The stable cyclodextrin-based coating was further functionalized with: i) targeting moieties to increase the nanoMOF interaction with specific receptors and ii) poly(ethylene glycol) chains to escape the immune system. These results pave the way towards the design of surface-engineered nanoMOFs of interest for applications in the field of targeted drug delivery, catalysis, separation and sensing.</jats:p

Natural Products Molten Together: Toward Multifunctional Hybrid Molecules with Specific Activities and Applications

It happens in Nature that compounds with interesting biological activity are formed of individual blocks of different structures, which are generally active by themselves. For example, different acids such as quinic acid or shikimic acid, are found to be conjugated to caffeic acid. In these cases the combination is the result of a biosynthetic process. At the same time, chemists were interested in melting together natural products known for specific activity in a way to obtain a multiple shot for the biological effect or also, sometimes, to enhance in vivo distribution. This chapter presents some examples of the research done in this way with a special focus on redox active compounds