title: Fluorogenic probes with substitutions at the 2 and 7 positions of cephalosporin are highly BlaC-specific for rapid Mycobacterium tuberculosis detection.
abstract: 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 β-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 β-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.
authors.affiliation: Molecular Imaging Program at Stanford, Departments of Radiology and Chemistry, Stanford University, 1201 Welch Road, Stanford, CA 94305-5484 (USA).
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Cheng
authors.forename: Hexin
authors.initials: H
authors.lastname: Xie
authors.forename: Preeti
authors.initials: P
authors.lastname: Sule
authors.forename: Hany
authors.initials: H
authors.lastname: Hassounah
authors.forename: Edward A
authors.initials: EA
authors.lastname: Graviss
authors.forename: Ying
authors.initials: Y
authors.lastname: Kong
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Cirillo
authors.forename: Jianghong
authors.initials: J
authors.lastname: Rao
mesh_terms: D001431:Bacteriological Techniques; D015415:Biomarkers / Q000032:analysis; D002511:Cephalosporins / Q000138:chemical synthesis / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D006867:Hydrolases / Q000032:analysis* / Q000737:chemistry; D015394:Molecular Structure; D009169:Mycobacterium tuberculosis / Q000737:chemistry / Q000201:enzymology / Q000302:isolation & purification*
chemical_list: D015415:Biomarkers; D002511:Cephalosporins; D005456:Fluorescent Dyes; D006867:Hydrolases
keywords: Mycobacterium tuberculosis; diagnostic tests; fluorogenic probes; lactams; β-lactamases