Beta-lactam compounds to detect carbapenemases or microbial carbapenem resistance are disclosed. The compounds contain a chemical probe. Upon hydrolysis by carbapenemases, the compounds undergo intramolecular rearrangement and release the chemical probe. Detection of the released chemical probe indicates the presence of carbapenemases and the presence of microbial carbapenem resistance.

Phenotypic antimicrobial susceptibility testing (AST), the gold-standard diagnostic that indicates whether an antimicrobial will be clinically effective, often suffer the slowest times-to-result for the most resistant pathogens. Here we introduce novel assays to be performed in parallel with standard AST assays that enable rapid, same-shift reporting of AST results for a plurality of pathogens. The assays developed here are further capable of detecting resistance to carbapenems, the most powerful class of beta-lactams commonly used as last-resort antimicrobials.

The present invention relates to the field of Mycobacterium tuberculosis. More specifically, the present invention provides compositions and methods for detecting M. tuberculosis. In a specific embodiment, a method comprises the steps of (a) contacting a patient sample with a solid support coated with antibodies to carbapenem resistance factor A (CrfA); washing unbound molecules from the solid support using a buffer; and incubating the solid support with a beta-lactamase substrate. In certain embodiments, the beta-lactamase substrate is chromogenic. In another embodiment, the method further comprises the step of visually detecting a color change from the hydrolysis of the substrate by CrfA protein bound to the antibodies on the solid support. In yet another embodiment, the method further comprises the step of measuring color intensity of the strip at 490 nm using a spectrophotometer.

A luminescent nanocomposite is provided comprising nanosheets comprising a transition metal selected from the group consisting of molybdenum and tungsten; a chalcogen element; and a rare earth element; and a beta-lactam dye disposed upon a surface of the nanosheets. Methods of using the luminescent nanocomposite to detect and remove mercury (II) ions from a fluid sample are also provided.

A nitrogen molecular sensor according to an embodiment of the present invention detects the nitrogen content in a plant. The nitrogen molecular sensor is manufactured by a novel method that includes the isolation of new nitrogen-sensitive genes. Transgenic rice plant containing the nitrogen sensor eventually may respond to nitrogen with high sensitivity. The biological nitrogen sensor can be applied to develop the crops improved nitrogen use efficiency through overcoming the current limitation of the phenotype characterization related to nitrogen metabolism in plants. As a result, it can be used as a core technology for isolating and analyzing industrially valuable genes involving in crop nitrogen use efficiency using a mutant pool harboring nitrogen sensor.

Creatinine levels may be monitored as a measure of kidney function. Conventionally, blood and/or urine tests are used for this purpose. Analyte sensors capable of monitoring creatinine in vivo may comprise: a sensor tail comprising at least a first working electrode, a creatinine-responsive active area disposed upon a surface of the first working electrode, a first membrane that is permeable to creatinine and overcoats the creatinine-responsive active area, and an oxygen scavenger located upon the sensor tail in proximity to the creatinine-responsive active area. The creatinine-responsive active area comprises a first electron transfer agent, a first polymer, and an enzyme system comprising multiple enzymes, particularly creatinine amidohydrolase, creatine amidohydrolase, and sarcosine oxidase, that are capable of acting in concert to facilitate detection of creatinine. An oxidase enzyme may serve as the oxygen scavenger, particularly glucose oxidase when detecting creatinine in fluids also containing glucose.

An electrochemical method is provided for in-vitro determination of the presence of bacteria producing lactamases, in a sample that may contain such bacteria.

Presented herein are methods 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.

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

A method of calibrating a device for measuring the concentration of creatinine using one or more calibration solutions, the method comprising: receiving concentrations at an initial time of creatine, Cr, and/or creatinine, Crn, of the one or more calibration solutions; receiving outputs of the measuring device at the end time; calculating the concentration of Cr and/or Crn in the calibration solutions at an end time using a temperature model, wherein the temperature model indicates an estimation of the temperature of the calibration solutions from the initial time to the end time, and wherein the temperature model includes a variable parameter; and determining a relationship between the outputs of the measuring device and the calculated concentrations of Cr and/or Crn.