The present invention relates to a method for screening a compound that inhibits secretion of toxins into host-cell cytoplasm by virulent bacteria using a needle type III secretion system. The compound of the invention is selected by screening for a compound which interacts with a loop region of the cytoplasmic domain of the membrane protein FlhB from Salmonella typhimurium or a paralog thereof. Compositions including the compound of the invention, use of the compound, and methods of treating disorders caused by virulent bacteria are also provided.

The invention provides a method for detecting bacteria. The method utilises a peptide that forms a complex with a conjugated reporter polymer and is susceptible to cleavage by one or more proteases on the surface of a bacteria. Presence or absence of the bacteria can be determined by assessing the optical absorption and/or colour and/or photoluminescence (e.g. fluorescence) of the conjugated reporter polymer, which may undergo a conformational change after binding with the to the cleaved peptide substrate. Specifically, the peptide substrate may comprise a cleavage site for digestion by the protease, and the protease may be an omptin protease. The conjugated reporter polymer may be selected from a polythiophene, a poly(1,4-phenylene vinylene) (PPV), a poly(1,4-phenylene) (PPP), a polyfluorenes (PFO), a nitrogen-containing polymer such as polyquinoline, poly(2,5-pyridinevinylene) (PPyV), 1,3,4-oxadiazole, and poly(9-vinylcarbazole) (PVK), and a polypyrrole. The method may be used to detect contamination in food or water, or as a clinical and/or diagnostic test.

An empirical Screen for Anti-infectives using Fluorescence microscopy of IntracellulaR Enterobacteriaceae (SAFIRE) was developed. Using this methodology, a library of small molecules and identified antimicrobials that are cell permeable and non-host-toxic were screened. Inhibitors of bacterial efflux pumps were identified as being implicated in antibiotic resistance and are attractive therapeutic targets for antimicrobials.

The invention provides compositions and methods for preventing, treating and diagnosing infection by Salmonella enterica serovar typhi (S. typhi) and/or S. paratyphi, i.e., typhoid fever.

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.

[Problem to be solved] To provide a method for identifying a marker for discriminating a microorganism based on a small amount of actual measurement data.

[Solution] A method for identifying a marker for discriminating a microorganism, including steps of: Step 1: Selecting a microorganism whose entire genome has been decoded, Step 2: Obtaining molecular weight-related ion peaks of a protein of the microorganism, Step 3: Obtaining an actual m/z value of each peak from the molecular weight-related ion peaks, Step 4: Calculating a theoretical m/z value of the protein present in the microorganism, Step 5: Comparing the theoretical m/z value with the actual m/z value, and assign the actual m/z value to a protein and an amino acid sequence thereof that have theoretical m/z values that match the actual m/z values, Step 6: Obtaining an amino acid sequence similar to the protein assigned in Step 5 above, Step 7: Calculating the theoretical m/z value of the protein of the microorganism selected according to discrimination and classification, and Step 8: Comparing the theoretical m/z values of the above protein and identify the theoretical m/z value with difference as a marker for discrimination.

Provided herein are compositions of trehalose phospholipids and uses thereof, e.g., compounds and compositions comprising 6,6′-diphosphatidyltrehalose (diPT) and analogs thereof with modifications of the diPT chemical scaffold, that bind and agonize Mincle, and the use thereof as adjuvants.

The present invention relates to an inert carrier Salmonella and potential use thereof, which is expected to be developed into a new inert carrier bacteria, and can be applied to the development of an indirect agglutination test method for simple and rapid detection of antigens or infected antibodies. The inert carrier Salmonella has been deposited in CGMCC in Beijing on Mar. 18, 2019 with the accession number of CGMCC No. 17340, and is classified as Salmonella sp. with a strain code of S9. The Salmonella has no visible agglutination reaction with various chicken sera derived from different genetic backgrounds, i.e., it has no non-specific agglutination reaction with chicken sera derived from broad range of genetic backgrounds.

A method for analyzing a microorganism according to the present invention includes: a step of reading, from a mass spectrum obtained by a mass spectrometric analysis of a sample containing a microorganism, a mass-to-charge ratio or ratios m/z of a peak or peaks originating from 1-10 kinds of proteins selected from the group, consisting of 10 kinds of proteins of gns, YaiA, YibT, PPI, L25, L21, S8, L17, L15 and S7 as well as any combination of the 10 kinds of proteins; and an identification step configured to determine, based on the read mass-to-charge ratio or ratios, m/z, of the peak or peaks, whether or not the microorganism contained in the sample contains at least one of the following six serotypes of Salmonella bacteria: Abaetetuba, Anatum, Newport, Poona, Tallahassee and Vellore.

Methods for rapidly concentrating a food sample for efficient detection of bacteria are disclosed. A microfiltration approach followed by centrifugation was used to concentrate the cells with an enzyme (e.g., a protease) added at the beginning of the process to facilitate more efficient micro-filtering. The enzyme was found to have no significant effect on cell viability.