The present invention relates to recombinant Gram-negative bacterial strains and the use thereof for delivery of heterologous proteins into eukaryotic cells.

The inventions described herein relate generally to the methods for monitoring the health of the mammalian gut by checking for whether dysbiotic parameters exceed a threshold level or not. In particular, this invention is directed to the use of parameters which correlate with the level of bifidobacteria, especially Bifidobacterium longum subsp. infantis in the mammalian colon.

A rapid assay for determining the presence of bacteria in a sample, such as a contaminated food sample, is disclosed. The assay comprises contacting the sample with a bacteria-specific ligand associated with a substrate, wherein bacteria present in the sample bind the ligand; contacting the bound bacteria with a detection agent; detecting the presence of bacteria in the sample by measuring the quantity of detection agent associated with the sample.

Provided herein are methods for selection of circular aptamers using a circular nucleic acid library. Also provided are circular aptamers, circular aptamer probes, biosensor systems, and the methods for their use in detecting a microorganism target, or a target molecule present on or generated from a microorganism or a virus in a test sample, including C. difficile glutamate dehydrogenase and methods for determining whether a subject has a C. difficile infection.

A microorganism identification method according to the present invention includes a step of subjecting a sample containing microorganisms to mass spectrometry to obtain a mass spectrum, a step of reading a mass-to-charge ratio m/z of a peak derived from a marker protein from the mass spectrum, and an identification step of identifying which bacteria of serovar of Salmonella genus bacteria the microorganisms contained in the sample contain, based on the mass-to-charge ratio m/z, in which at least one of two types of ribosomal proteins S8 and Peptidylpropyl isomerase is used as the marker protein.

What is disclosed relates to the detection and identification of bacteria of the genera Salmonella and Shigella. It relates more precisely to the methods of microbiology and the culture media used for the detection, identification, isolation and/or analytical investigation of these bacteria. Relating to a method for enrichment and selective culture of bacteria of the genera Salmonella and/or Shigella contained in a biological sample. In the method, some or all of the sample is seeded in/on a culture medium including a nutrient component that favors the development and growth of the bacteria, and includes L-ornithine as a selective agent. It also covers a culture medium suitable for carrying out this method.

Devices and methods for the detection of analytes are disclosed. Devices and methods for detecting food-borne pathogens are disclosed.

Selective enrichment media and methods for selectively growing and detecting Salmonella spp. and/or Shiga toxin-producing E. coli. The media may comprise a carbon and nitrogen source, an inorganic salt, a fermentable sugar, one or more selective agents, and an efflux pump inhibitor. Various selective agents include sulfa drugs, surfactants, aminocoumarins, cycloheximide, supravital stains, ascorbic acid, bromobenzoic acid, myricetin, nitrofurantoin, rifamycins, polyketides, and oxazolidinones. Various efflux pump inhibitors include arylpiperazines, such as 1-(1-naphthylmethyl)piperazine, and quinoline derivatives, such as 4-chloroquinoline. Methods of selectively growing and detecting Salmonella and/or Shiga toxin-producing E. coli are provided.

The present invention concerns a method for labeling specifically living bacteria of a given category of bacteria in a sample comprising bacteria, the method comprising the steps of: a) incubating said bacteria of said sample with at least one analog of a monosaccharide compound, said monosaccharide being an endogenous monosaccharide residue of glycans of the outer membrane of such given category of bacteria, the said endogenous monosaccharide residue comprising an ulosonic acid or ulosonate salt residue, the said analog of a monosaccharide compound being a modified monosaccharide substituted at a given position by a first reactive chemical group capable to react with a second reactive group of a labeling molecule, the said given position being preferably a position which comprises a free group in the said endogenous monosaccharide residue incorporated within said glycans of the outer membrane of the bacteria, b) contacting said bacteria with a said labeling molecule comprising a said second reactive group, for generating the reaction of said first reactive group of said analog residue incorporated within said glycans of the outer membrane of said living bacteria with said second reactive group of said labeling molecule.

Certain embodiments are directed to paper/polymer hybrid microfluidic devices integrated with nano-biosensors for pathogen detection and infectious disease diagnosis.