Electrochemistry Microbial Sensors For Drug Susceptibility Testing Of Mycobacterium Tuberculosis

TB,which is caused by the Mycobacterium tuberculosis(M.tb),is one of the ancient global infectious diseases.With the irregular use of anti-TB drugs,the mutation of M.tb and etc,TB presents different types of drug-resistance,like single drug-resistant tuberculosis(DR-TB),multi drug-resistant tuberculosis(MDR-TB)and extensively drug-resistant(XDR-TB).Under the circumstances,a rapid and accurate drug susceptibility testing(DST)of M.tb is essential for treating TB.As current DST is time-cosuming and the correct rate is low,we creatively developed two biosensors for DST of M.tb.The main results are as follows:1)Microbial sensor based on the oxygen electrode: The sensor is made of an oxygen electrode with M.tb attached to its surface.This sensor monitors the residual oxygen consumption of anti-TB drugs treated M.tb with glycerine.After drug pretreatment for 4 days,the response differences are distinguishable between the sensors made of drug-sensitive M.tb isolates and the sensors made of drug-resistant M.tb isolates.The DST of the M.tb H37 Ra strain,its mutants and 35 clinical isolates to six common anti-TB drugs: rifampin(RIF),isoniazid(INH),streptomycin(STR),ethambutol(EMB),levofloxacin(LVX)and para-aminosalicylic acid(PAS),were tested using the microbial sensor.The accuracy of the microbial sensor is 97.1% based on the DST result.and the whole procedure takes approximately 11 days.2)An impedance sensor creatively developed for DST of M.tb.The impedance sensor could monitor the impedance changes in real time during the M.tb proliferation after immobilizing M.tb specific antibodies on the electrode surface.The DST of the M.tb H37 Ra strain,its mutants and 35 clinical isolates to six common anti-TB drugs: RIF,INH,STR,EMB,LVX and PAS,were tested using the impedance sensor.The accuracy of the impedance sensor is 84.8% based on the DST result,and the whole procedure takes approximately 9 days.The new sensors for DST in this study are also applicable to other bacteria(eg E.coli,M.smegmatis).The sensors,which has the advantages of simplified steps,short detection time and high accuracy for a DST result.Especially,the impedance sensor could achieve high throughput detection.As a new monitoring platform for the DST of M.tb,the two sensors are expected to be extensively used for clinical diagnose as a new generation product which could provide essential guidance for clinical therapy.