초록 ▼

This invention presents rapid methods for evaluating the effects of antimicrobial compounds on microorganisms based upon the microorganism's ability to transport electrons to an external chemical oxidant (a mediator) that is added to the microorganism sample. The mediator interacts with the terminal

This invention presents rapid methods for evaluating the effects of antimicrobial compounds on microorganisms based upon the microorganism's ability to transport electrons to an external chemical oxidant (a mediator) that is added to the microorganism sample. The mediator interacts with the terminal components of the respiratory pathway and the extent of its consumption is related to the ability of the microorganism to respire. However, under the assay conditions described herein the extent of mediator consumption is different from the microorganisms' ability to consume oxygen, due to the addition of metabolizable compounds to the assay mixtures. The consumed mediator is subsequently measured electrochemically (amperometrically or coulometrically) at the working electrode of a standard two-electrode or three-electrode electrochemical cell. The electrochemical signals (change of current or charge with time) obtained with microorganism suspensions incubated in the absence and presence of antimicrobial compounds are significantly different. These signal differences can be used to screen for antimicrobial effectiveness of antibiotic drugs against clinically important multi-drug-resistant organisms, to screen for the presence of unlawful levels of antibiotic compounds in foodstuffs, or to screen potential new antimicrobial compounds for effectiveness against different species of microorganisms.

대표청구항 ▼

1. A method of rapidly assessing susceptibility of a microorganism to a drug selected from the group consisting of an antibiotic and a cytotoxic compound, said method comprising the steps of:obtaining a test sample of a microorganism; arresting growth of the microorganism in the test sample; adding

1. A method of rapidly assessing susceptibility of a microorganism to a drug selected from the group consisting of an antibiotic and a cytotoxic compound, said method comprising the steps of:obtaining a test sample of a microorganism; arresting growth of the microorganism in the test sample; adding a mediator to a test sample of said microorganism in the presence of said drug; said mediator being reducible by accepting an electron arising from respiration of the microorganism; determining variation of the respiration rate of the microorganism over time by electrochemical measurement of mediator reduction in the test sample resulting from microorganism respiration, said variation of the respiration rate being observable over a time period of up to 500 seconds; and comparing variation of the respiration rate of the test sample with variation of the respiration rate in a control sample of the microorganism not exposed to said drug, thereby assessing susceptibility of the microorganism to the drug.