A method for determining the activity of creatininase includes providing an amount of creatininase to be measured for enzyme activity and providing an excess amount of creatinine, the excess amount being greater than an amount that will ordinarily react with the amount of creatininase. The method further includes reacting the amount of creatininase with the excess amount of creatinine to produce creatine. The method further includes reacting the creatine with diacetyl and 1-naphatol and producing a pink color. The method further includes measuring an intensity of the pink color and determining an amount of the creatine that was created based on the intensity. The method further includes calculating a specific activity of the creatininase based on the amount of creatine.

Based on the discovery that MBLAC1 is a specific, high-affinity target for Ceftriaxone (Cef), MBLAC1 may be used for identifying treatments for addiction to substances of abuse. Methods for identifying therapeutic agents for treatment of addiction to a substance of abuse include using an assay to determine if a test agent is capable of binding to MBLAC1 or disrupting binding between MBLAC1 protein and Cef, and identifying such a test agent as a candidate therapeutic agent for treatment of addiction to a substance of abuse. MBLAC knock-out (KO) animals, methods of use thereof, and kits are used for identifying a therapeutic agent that reduces the actions of at least one substance of abuse. Methods also include using cellular extracts from tissue or cultured cells taken from wild-type (WT) MBLAC1 and MBLAC1 KO animals for screening for novel, Cef-like molecules in vitro, and using cells from a MBLAC1 KO animal to test for Cef-like actions of a test molecule.

Probes for the detection of β-lactamase-type enzymatic activity. In particular, novel fluorogenic substrates for detecting the presence of a catalytically active β-lactamase and a detection method using such substrates.

The present invention relates to a method for detecting a pathogenic strain having resistance to carbapenem antibiotics in a biological sample. According to the present invention, it is possible to directly identify carbapenemases, specifically KPC, OXA, NDM, IMP, VIM and/or GES protein, by mass spectrometry, thereby making it possible to quickly determine not only whether a pathogenic strain has resistance to antibiotics, but also the type of protein involved in the resistance. According to the present invention, the physical and chemical properties of each carbapenemase in vivo, such as the unique N-terminal truncation length, methionine residue oxidation and disulfide bond formation in each type of carbapenemase, are identified and are reflected on reference mass values. Accordingly, it is possible to more closely detect the presence of an antibiotic-resistant strain with high reliability, and thus the present invention may be advantageously used to establish an appropriate strategy for antibiotic administration at an early stage of infection.

Methods and compositions for detecting an antibiotic-inactivating factor produced by a microorganism are described herein.

Presented herein are methods, compositions, and kits for the detection of specific beta-lactamases, including class A serine carbapenemases, metallo-beta-lactamases, AmpC beta-lactamases, and extended-spectrum beta-lactamases (ESBLs). The methods presented herein include methods that permit the detection of the presence of specific beta-lactamases in bacterial samples within as few as 2 to 10 minutes.

The present disclosure features portable wide field fluorimeter systems, e.g., in the form of low-cost mobile platforms, and methods to perform fluorometric assays to detect a change in fluorescence intensity in liquid samples, e.g., caused by the presence of a target analyte, e.g., a protein, e.g., an enzyme (e.g., β-lactamase) expressed by a target pathogen in a liquid sample in a point-of-care setting. In some implementations, a portable system for detecting a change in fluorescence intensity in a liquid sample includes a microfluidic device, an optical assembly including an emission filter and one or more lenses, and an analyzer device that collects and processes a fluorescent signal for the detection of a target analyte produced by the target pathogen present in the liquid sample.

The present invention relates to methods for determining the concentration of a carbapenem antibiotic in a biological sample. In particular, the present invention relates to methods for determining the concentration of a carbapenem antibiotic in a biological sample, comprising the steps of: (a) providing a blaOXA-48 class D beta-lactamase (blaOXA-48) or a functionally active variant or fragment thereof; (b) providing a biological sample; (c) contacting the blaOXA-48 or functionally active variant or fragment thereof with the biological sample; and (d) determining the concentration of the carbapenem antibiotic in the biological sample.

A compound which is a thienolate of formula (I) or a pharmaceutically acceptable salt thereof: (I) wherein R.sup.1, R.sup.3, Ring A1, n and Ring A2 are as defined herein, are found to be useful in inhibiting metallo-beta-lactamase and therefore in potentiating the activity of beta lactamase antibiotics. The compound can be used alone or in combination with a rhodanine of formula (II) or a pharmaceutically acceptable salt thereof: (II) wherein R.sup.3, Ring A1, n, Ring A2, L and Ring B are as defined herein. Treatment or prevention of bacterial infection in combination with beta-lactam antibiotic agents is also provided.

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A method of calibrating a device for measuring the concentration of creatinine in a sample including one or more enzyme modulators, the method comprising: determining sensitivities of the device for each of two or more calibration solutions, wherein each calibration solution has a different amount of enzyme modulator; determining a degree of modulation for each of the two or more calibration solutions; determining a degree of modulation for a sample to be measured; and calculating the sensitivity of the device for the sample, wherein said calculating comprises modifying the sensitivity of one of the two or more calibration solutions by a function comprising the determined degrees of modulation.