Secretion of the human parathyroid hormone through a microcin type I secretion system in Escherichia coli.

Background: Gram negative bacteria possess different secretion systems to export proteins to the extracellular medium. The simplest one, type I secretion system (T1SS), forms a channel across the cell envelope to export proteins in a single step. Peptides secreted by the T1SSs comprise a group of antibiotics, called class II microcins, which carry an amino terminal secretion domain that is processed concomitantly with export.

Genetics of resistance to trimethoprim in cotrimoxazole resistant uropathogenic : integrons, transposons, and single gene cassettes.

Cotrimoxazole, the combined formulation of sulfamethoxazole and trimethoprim, is one of the treatments of choice for several infectious diseases, particularly urinary tract infections. Both components of cotrimoxazole are synthetic antimicrobial drugs, and their combination was introduced into medical therapeutics about half a century ago. In Gram-negative bacteria, resistance to cotrimoxazole is widespread, being based on the acquisition of genes from the auxiliary genome that confer resistance to each of its antibacterial components.

Protocol for live imaging of bacteria-cell interactions in genetically modified mouse small intestinal organoids.

Here, we present a protocol for microinjection of bacteria into mouse small intestinal organoids that recapitulates the natural route of infection of intestinal epithelial cells from the intestinal lumen. We describe steps for visualizing bacteria-cell interactions by live imaging of infected organoids using light sheet microscopy. We then detail procedures for generating doxycycline-inducible expression of mutant proteins in organoids to study essential gene functions.

Strict relationship between class 1 integrons and resistance to sulfamethoxazole in Escherichia coli.

Antibiotic resistance is a health concern. Class 1 integrons (Int1) are genetic elements that contribute to the problem, as they carry different antibiotic resistance genes in their variable region, frequently dfrA (resistance to trimethoprim) and, in their conserved region, the sul1 gene (resistance to sulfonamides, e.g.

Live Imaging Reveals Listeria Hijacking of E-Cadherin Recycling as It Crosses the Intestinal Barrier.

Listeria monocytogenes is a foodborne bacterial pathogen that causes human listeriosis, a severe systemic infection. Its translocation across the intestinal epithelium is mediated by the interaction of internalin (InlA), a Listeria surface protein, with its host-species-specific receptor E-cadherin (Ecad). It occurs through goblet cells, on which Ecad is luminally accessible, via an unknown mechanism.