Electrochemiluminescence-based detection of beta-lactam antibiotics and beta-lactamases.
Bacterial resistance to clinically administered beta-lactam antibiotics is usually caused by beta-lactamases, enzymes that hydrolytically inactivate the antibiotics. This paper describes the use of electrogenerated chemiluminescence (ECL) to detect beta-lactam antibiotics and their hydrolysis by beta-lactamases. All 10 tested antibiotics were detected on the basis of their ability to participate in an ECL reaction with ruthenium(II) tris(bipyridine). In every case, antibiotic-promoted ECL changed when the antibiotic was hydrolyzed by beta-lactamases or NaOH. Standard curves of antibiotic concentration versus ECL intensity showed that antibiotics could be quantitated to low micromolar concentrations. Substrate profiles were generated for four beta-lactamases using six structurally diverse beta-lactam antibiotics. ECL-based antibiotic detection was accomplished in untreated whole milk, and beta-lactamases were detected in crude bacterial broth culture. Because several structurally diverse antibiotics were detectable by ECL, this method may become valuable for the detection of many or all beta-lactam antibiotics and their inactivation by beta-lactamases.
Liang
P
P
IGEN, Inc., Gaithersburg, Maryland 20877, USA.
Sanchez
R I
RI
Martin
M T
MT
D000900:Anti-Bacterial Agents / Q000032:analysis*; D004350:Drug Residues; D004563:Electrochemistry / Q000379:methods*; D005506:Food Contamination; D008163:Luminescent Measurements; D008826:Microbial Sensitivity Tests; D001618:beta-Lactamases / Q000032:analysis*; D047090:beta-Lactams
D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D001618:beta-Lactamases