Liang P, Sanchez R I, Martin M T
IGEN, Inc., Gaithersburg, Maryland 20877, USA.
Anal Chem. 1996 Jul 15;68(14):2426-31. doi: 10.1021/ac951072p.
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.
细菌对临床使用的β-内酰胺类抗生素产生耐药性通常是由β-内酰胺酶引起的，β-内酰胺酶是一类能通过水解作用使抗生素失活的酶。本文描述了利用电化学发光（ECL）来检测β-内酰胺类抗生素以及它们被β-内酰胺酶水解的情况。所有10种受试抗生素都是基于它们与三联吡啶钌（II）参与ECL反应的能力而被检测出来的。在每种情况下，当抗生素被β-内酰胺酶或氢氧化钠水解时，抗生素促进的ECL都会发生变化。抗生素浓度与ECL强度的标准曲线表明，抗生素能够被定量到低微摩尔浓度。使用六种结构各异的β-内酰胺类抗生素为四种β-内酰胺酶生成了底物谱。基于ECL的抗生素检测在未处理的全脂牛奶中得以实现，并且在粗制细菌肉汤培养物中检测到了β-内酰胺酶。由于几种结构各异的抗生素都能通过ECL被检测到，所以该方法对于检测许多或所有β-内酰胺类抗生素以及它们被β-内酰胺酶灭活的情况可能会变得很有价值。
