Fluorogenic Probes with Substitutions at the 2 and 7 Positions of Cephalosporin are Highly BlaC-Specific for Rapid Mycobacterium Tuberculosis Detection.

Angewandte Chemie (International ed. in English)

PubMedID: 24989449

Cheng Y, Xie H, Sule P, Hassounah H, Graviss EA, Kong Y, Cirillo JD, Rao J. Fluorogenic Probes with Substitutions at the 2 and 7 Positions of Cephalosporin are Highly BlaC-Specific for Rapid Mycobacterium Tuberculosis Detection. Angew Chem Int Ed Engl. 2014;.
Current methods for the detection of Mycobacterium tuberculosis (Mtb) are either time consuming or require expensive instruments and are thus are not suitable for point-of-care diagnosis. The design, synthesis, and evaluation of fluorogenic probes with high specificity for BlaC, a biomarker expressed by Mtb, are described. The fluorogenic probe CDG-3 is based on cephalosporin with substitutions at the 2 and 7 positions and it demonstrates over 120?000-fold selectivity for BlaC over TEM-1 Bla, the most common ß-lactamase. CDG-3 can detect 10 colony-forming units of the attenuated Mycobacterium bovis strain BCG in human sputum in the presence of high levels of contaminating ß-lactamases expressed by other clinically prevalent bacterial strains. In a trial with 50 clinical samples, CDG-3 detected tuberculosis with 90?% sensitivity and 73?% specificity relative to Mtb culture within one hour, thus demonstrating its potential as a low-cost point-of-care test for use in resource-limited areas.