Development of impedimetric sensor for E.coli M-17 antibiotic susceptibility testing

A miniature impedimetric sensor element (I SE), integratable into a laboratory-on-a-chip for testing the antibiotic resistance of microorganisms is described. The topology, design and manufacturing technology of ISE based on interdigital electrodes are described. With the help of a sample of chips, measurements were made on the evaluation of antibiotic resistance (ABR) of microorganisms, using E. coli M-17 as a model, under the influence of a number of antibiotics. The possibility of using the developed sensor element for ABR estimation at the exposure time of 1 to 2 hours is shown experimentally. The concentration sensitivity limit of the sensor element was determined. Frequency dependences of the electrical impedance for E. coli M-17 with various antimicrobial agents were obtained. The susceptibility of investigated bacterial type to ceftazidime and ceftriaxone as well as a lack of susceptibility to benzylpenicillin has been experimentally confirmed. A numerical parameter is proposed for assessing the degree of antibiotic resistance of microorganism.