Genes mcr improve the intestinal fitness of pathogenic E. coli and balance their lifestyle to commensalism.

Background: The plasmid-mediated resistance gene mcr-1 confers colistin resistance in Escherichia coli and paves the way for the evolution to pan-drug resistance. We investigated the impact of mcr-1 in gut colonization in the absence of antibiotics using isogenic E. coli strains transformed with a plasmid encoding or devoid of mcr-1.

Mesenchymal content of fresh bone marrow: a proposed quality control method for cell therapy.

The scarcity of mesenchymal stem cells (MSC) in bone marrow (BM) has justified their ex vivo expansion before therapeutic use, but a method to evaluate the quality of initial mesenchymal content and track the modifications induced by graft processing has not yet been proposed. The aim of this study was to establish such a procedure. Flow cytometric and functional assay methods were modified to count CD45(-) CD14(-)/CD73(+) subsets containing all MSC and used them to study BM from spongy bone (SB) and iliac crest aspirate (ICA).

Characterization of nonexpanded mesenchymal progenitor cells from normal adult human bone marrow.

Objective: Adult bone marrow (BM) mesenchymal stem/progenitor cells (MS/PC) are a potentially useful tool for cell therapy and tissue repair. However, the identification of cell subsets rich in MS/PC from fresh BM has not been described. We have developed a means of identifying such subsets from untouched bone marrow.

CD34+CDw90(Thy-1)+ subset colocated with mesenchymal progenitors in human normal bone marrow hematon units is enriched in colony-forming unit megakaryocytes and long-term culture-initiating cells.

Objective: The progress made in the supportive care of allografts and the identification of mesenchymal stem cells in adult human bone marrow (BM) has prompted renewed interest in the use of BM as a form of cell therapy. With the aim of optimizing the collection of BM cells, we evaluated the hematopoietic and mesenchymal immature cell contents of BM hematon units (HUs), which usually are eliminated during graft processing.

Materials And Methods: Hematopoietic CD34+ progenitors from HU and buffy coat (BC) compartments were characterized in short-term culture.