The Research of Multi-channel Series Piezoelectric Quartz Crystal Sensor on Post-antibiotic Effect and Mutant Prevention Concentration
|Keywords||Post-antibiotic effect ( PAE ) Combined post-antibiotic effect ( PAE ) Mutant prevention concentration ( MPC ) Escherichia coli Pseudomonas aeruginosa Staphylococcus aureus Multi-channel series piezoelectric quartz crystal (MSPQC) Frequency detection time (FDT)|
Antibiotic resistance is becoming an increasingly serious problem with the indiscriminate and inappropriate use of antibiotics. To slow the development of resistance, scientists in clinical settings focus on the establishment of change the dose or method for the characteristics of the new treatment strategy and put forward some new theory, which is quite noticeable is that post-antibiotic effect (PAE) and antibiotics mutant prevention concentration (MPC). PAE and the MPC can objectively reflect the efficacy of antibiotics, and they have been proposed as a new guide for physicians in the selection of appropriate administration regimens.Multi-channel series piezoelectric quartz crystal (MSPQC) sensor has been extensively used in rapid detection of microorganisms field, and this method is sensitive and rapid. MSPQC method was applied to study for PAE and MPC. PAE and MPC detected by MSPQC is the new evidence for clinician to direct patient to take medicine .The new methods broaden their application in detection of microorganisms field. The main content of this thesis is as follow:(1) A novel method was proposed for detection of post-antibiotic effect(PAE)by MSPQC. The PAE of ampicillin, cefotaxime and gentamicin at 1x, 2x and 4x MIC on Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 29213 were studied by proposed method. For comparing, the classic method of viable counts on agar were run at the same time. The experimental results showed that MSPQC method had a good agreement with the comparing method. Gentamicin produces the longest PAEs for gram-negative organisms ; Beta-lactam antibiotics produce little or negative PAE with gram-negative organisms. Proposed method is simple, rapid, and the information can be recorded in real time. PAE detected by MSPQC is a new evidence for clinician to direct dosage, dosing time interval and dosing frequency.(2) MSPQC method was proposed for detection of combined PAE. The combined PAE can be calculated by measuring the difference of the FDT between the control and treated group. PAE of gentamicin in combination with cefotaxime,ciprofloxacin on Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853 were studied by MSPQC. For comparison, the classic method of viable counts on agar were run at the same time. The experimental results showed that MSPQC method had a good agreement with the comparing method.The combination of gentamicin and cefotaxime had an additive PAE against Escherichia coli and a synergistic effect against Pseudomonas aeruginosa The combination of gentamicin and ciprofloxacin had an additive PAE against Escherichia coli and Pseudomonas aeruginosa This combination therapy is rationa1, experimental results are consistent with results in the literature. PAE detected by MSPQC has opened a new era for studying combination therapy.(3) A novel method was proposed for detection of mutant prevention concentration(MPC)by multi-channel series piezoelectric quartz crystal (MSPQC). According to the definition of MPC by agar dilution , MSPQC method was proposed to detect it when there was no FDT in frequency curve. This method was used to detect MPC of Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853、Staphylococcus aureus ATCC 29213 and their resistant mutants against ampicillin, cefotaxime and gentamicin. Comparing tests were run at the same time by the agar dilution method.The experimental results showed that they matched well. MPC detected by MSPQC has opened a new era for studying the mechanism of antibiotic resistance and has been proposed as a new guide for physicians in the selection of appropriate administration regimens.