The invention relates to a method for labeling specifically living microorganisms in a sample comprising microorganisms, the method comprising the steps of: a) incubating said microorganisms of said sample with at least one modified monosaccharide compound comprising a first reactive chemical group capable to chemically react with a second reactive group, so that a residue bearing said first reactive group is incorporated into such microorganisms, and b) contacting said residue incorporated in the microorganisms, with a labeling molecule comprising a said second reactive group, for generating the chemical reaction of said first reactive group of said residue incorporated within said living microorganisms with said second reactive group of said labeling molecule, resulting in a covalent link, characterized in that the said modified monosaccharide compound has the following formula (I′), or a salt thereof: —X can be O, NH or S, preferably O and NH, and —R1 and R2 can be independently H, OH, NH.sub.2, OH and NH.sub.2 being substituted or not by protecting groups thereof, preferably substituted by alkyl, hydroxyalkyl, acyl, formyl or imidoyl groups, and —R3 is H or an alkyl chain in C.sub.1 to C.sub.4, each carbon being substituted or not substituted by OH or NH.sub.2 substituted or not by protecting groups thereof, preferably by alkyl, hydroxyalkyl, acyl, formyl or imidoyl groups, and —at least one of X, R1, R2 and R3 groups, preferably R3, being substituted by a said first reactive group Ra. ##STR00001##

The present invention relates to methods and compositions for preventing and treating Staphylococcus aureus in a subject. Therapeutic compositions of the present invention comprise leukocidin E and/or D proteins or polypeptides and anti-leukocidin E and/or D antibodies. The invention further relates to methods of identifying inhibitors of LukE/D cytotoxicity and inhibitors of LukE/D-leukocyte binding.

Disclosed are compositions, methods and systems for detecting MRSA, for example MRSA nasal colonization. In certain embodiments, the methods use bacteriophage-based amplification of the signal in detection of bacteria and other microorganisms to detect MRSA. The methods for detecting MRSA may include preparing an assay comprising a selective agent and a cocktail comprising at least two different types of recombinant bacteriophages, incubating the sample in the assay, capturing an indicator protein product, and detecting an indicator protein product produced by the recombinant bacteriophage, wherein positive detection of the indicator protein product indicates that MRSA is present in the sample.

Disclosed herein are isolated and purified Staphylococcus aureus bi-component leukocidin, referred to herein as LukAB, and its components LukA and LukB, antibodies specific to LukA, antibodies specific to LukB, therapeutic compositions containing LukA and/or LukB, or anti-LukA and/or anti-LukB antibodies, uses of the compositions to treat acute inflammatory conditions or S. aureus infection, methods for identifying inhibitors of LukAB-mediated cytotoxicity of human phagocytes, and methods for using LukAB as a marker to predict severity of S. aureus infection.

In alternative embodiments, the invention provides vaccines, pharmaceutical compounds and formulations for diagnosing, preventing, treating or ameliorating Group A Streptococcus (GAS), Group C Streptococcus (GCS), or Group A Streptococcus (GGS), infections, or other pathogenic Streptococcus infections. In alternative embodiments, the invention provides compositions such as diagnostic tests, assays, immunoassays and test strips, and methods, for detecting or diagnosing the presence of a Streptococcal infection, e.g., Group A Streptococcus (GAS), Group C Streptococcus (GCS), or Group A Streptococcus (GGS), infections, or other pathogenic Streptococcus infections.

Described herein are engineered microbe-targeting or microbe-binding molecules, kits comprising the same and uses thereof. Some particular embodiments of the microbe-targeting or microbe-binding molecules comprise a carbohydrate recognition domain of mannose-binding lectin, or a fragment thereof, linked to a portion of a Fc region. In some embodiments, the microbe-targeting molecules or microbe-binding molecules can be conjugated to a substrate, e.g., a magnetic microbead, forming a microbe-targeting substrate (e.g., a microbe-targeting magnetic microbead). Such microbe-targeting molecules and/or substrates and the kits comprising the same can bind and/or capture of a microbe and/or microbial matter thereof, and can thus be used in various applications, e.g., diagnosis and/or treatment of an infection caused by microbes such as sepsis in a subject or any environmental surface. Microbe-targeting molecules and/or substrates can be regenerated after use by washing with a low pH buffer or buffer in which calcium is insoluble.

The present invention relates to proteins and nucleic acids derived from Staphylococcus aureus as well as therapeutic and diagnostic uses of the proteins and nucleic acids.

Antibodies and antigen binding fragments thereof directed against Staphylococcus aureus (S. aureus) surface determinant antigens and secreted toxins are disclosed. Methods of detecting, diagnosing and treating S. aureus using the antibodies and antigen binding fragments thereof are also provided.

The present invention includes a novel method and system for identification of microorganisms in samples that proteins and other biological material from non-microorganism sources (e.g., proteins of mammalian origin) that can interfere with identification of the microorganisms. The methods and systems described herein include use of a single-use chromatography medium to purify intact proteins prior to mass spectrometry analysis. The chromatography medium and the methods described herein can rapidly and efficiently remove of a substantial portion of interfering biological material (e.g., mammalian proteins) from a crude cell lysate while preserving high signal strength and removing enough of the interfering protein(s) to allow for identification of the microorganism(s) by mass spectrometry analysis.

The present disclosure is directed to antibodies binding to and inhibiting S. aureus and methods for use thereof.