Described herein are variants of alpha-hemolysin having at least one mutation, such as a mutation to a positive charge. In certain examples, the mutation is selected from V149K, E287R, H35G, T109K, P151K, K147N, E111N, M113A, or combinations thereof in the mature, wild-type alpha-hemolysin amino acid sequence. The α-hemolysin variants may also include a substitution at H144A and/or a series of glycine residues spanning residues 127 to 131 of the mature, wild-type alpha hemolysin. Also provided are nanopore assemblies including the alpha-hemolysin variants, the assembly having a decreased time-to-thread. The decreased time-to-thread, for example, increases DNA sequencing efficiency and accuracy.

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.

The invention provides a method for identifying methicillin resistant Staphylococcus aureus (MRSA) in a bacterial sample comprising the steps: classifying bacteria in the sample as Staphylococcus aureus (SA) and determining the presence or absence of the phenol soluble modulin peptide or a variant thereof wherein the presence of the PSM-mec peptide or variant thereof indicates methicillin resistant Staphylococcus aureus. The variant is preferably the formylated version of the PSM-mec peptide having a mass to charge ratio of 2415 in a singly protonated state.

The invention relates to a method for determining a target molecule in a sample. Also, the invention relates to a Förster resonance energy transfer (FRET, fluorescence resonance energy transfer) pair, recombinant antibodies, or antigen binding fragments thereof that bind Staphylococcus aureus Enterotoxin A and a test kit comprising the FRET pair, antibody or antigen binding fragment. Furthermore, the present invention relates to an isolated nucleic acid molecule comprising a nucleotide sequence that encodes the recombinant antibody or antigen binding fragment, and an expression vector comprising said nucleic acid molecule. Still, the invention relates to use of the FRET pair or the recombinant antibody or an antigen binding fragment thereof for determining a target molecule such as Staphylococcus aureus Enterotoxin A in a sample. And still, the invention relates to a method of producing the antibody or antigen binding fragment.

The present invention discloses crystal structure of Staphylococcus aureus Clumping factor A (ClfA) in complex with fibrinogen (Fg) derived peptide. Also, the present invention also discloses the use of this structure in the design of ClfA targeted vaccines and therapeutic agents (including monoclonal antibodies). In addition, the present invention discloses isolated and purified engineered Staphylococcus clumping factor A protein (ClfA) with a stabilized, closed conformation and immunogenic compositions thereof including methods of treating a Staphylococcus infection in an individual.

Devices, systems and methods including a sonicator for sample preparation are provided. A sonicator may be used to mix, resuspend, aerosolize, disperse, disintegrate, or de-gas a solution. A sonicator may be used to disrupt a cell, such as a pathogen cell in a sample. Sample preparation may include exposing pathogen-identifying material by sonication to detect, identify, or measure pathogens. A sonicator may transfer ultrasonic energy to the sample solution by contacting its tip to an exterior wall of a vessel containing the sample. Multipurpose devices including a sonicator also include further components for additional actions and assays. Devices, and systems comprising such devices, may communicate with a laboratory or other devices in a system for sample assay and analysis. Methods utilizing such devices and systems are provided. The improved sample preparation devices, systems and methods are useful for analyzing samples, e.g. for diagnosing patients suffering from infection by pathogens.

The invention discloses an immunoglobulin-binding magnetic bead, comprising a porous matrix and one or more magnetic particles embedded in said matrix, wherein said matrix comprises a porous polymer and at least 10 mg/ml Fc-binding proteinaceous ligands covalently coupled to said porous polymer.

Described herein are variants of alpha-hemolysin having at least one mutation, such as a mutation to a positive charge. In certain examples, the mutation is selected from V149K, E287R, H35G, T109K, P151K, K147N, E111N, M113A, or combinations thereof in the mature, wild-type alpha-hemolysin amino acid sequence. The α-hemolysin variants may also include a substitution at H144A and/or a series of glycine residues spanning residues 127 to 131 of the mature, wild-type alpha hemolysin. Also provided are nanopore assemblies including the alpha-hemolysin variants, the assembly having a decreased time-to-thread. The decreased time-to-thread, for example, increases DNA sequencing efficiency and accuracy.

The invention relates to a method for identification and discrimination of bacteria and/or mutant bacterial strains in a biological fluid. The method includes illuminating the biological fluid with a beam of light; obtaining Raman data from light scattered from the illuminated biological fluid; and finding Raman signatures corresponding to each type of bacteria and/or mutant bacterial strains from the obtained Raman data, so as to identify and discriminate each type of bacteria and/or mutant bacterial strains in the biological fluid from the Raman signatures.

We provide new monoclonal antibody inhibitors of coagulases staphylocoagulase and vWbp for treatment of S. aureus. The monoclonal antibodies are useful in targeting the SC N-terminus of SC and vWbp (respectively) and inhibiting prothrombin activation. The monoclonal antibodies are able to bind to and interfere with, modulate, and/or inhibit the binding interactions between the coagulase protein and its ligand protein prothrombin in blood and tissues. The antibodies are effective in inhibiting the activation of prothrombin.