title: Monitoring of Mycoplasma genitalium growth and evaluation of antibacterial activity of antibiotics tetracycline and levofloxacin using a wireless magnetoelastic sensor.
abstract: Mycoplasma genitalium (Mg) is the smallest and simplest self-replicating bacteria lacking of cell wall and is a human pathogen causing various diseases. This paper describes the real-time, long-term and in situ monitoring of the growth of Mg and evaluation of the effect of the antibiotics tetracycline and levofloxacin on the growth using a wireless magnetoelastic sensor. The sensor is fabricated by coating a magnetoelastic strip with a polyurethane protecting film. In response to a time-varying magnetic field, the sensor longitudinally vibrates at a resonance frequency, emitting magnetic flux that can be remotely detected by a pick-up coil. No physical connections between the sensor and the detection system are required. The wireless property facilitates aseptic operation. The adhesion of Mg on the sensor surface results in a decrease in the resonance frequency, which is proportional to the concentration of Mg. The shift of the resonance frequency-time curves shows that under routine culture condition the growth curve of Mg is composed of three phases those are lag, logarithmic and stationary phase, respectively. In the presence of the antibiotics, the lag phase in the growth inhibition curves is prolonged obviously and the stationary phase is substituted by a decline phase. The growth inhibition of Mg is related to the concentration of the antibiotics. The MIC50 (minimal inhibitory concentration) of Mg incubated in the presence of the antibiotics for 120h is calculated to be 1.5 and 0.5 microg/mL for tetracycline and levofloxacin, respectively.
authors.affiliation: College of Chemistry & Chemical Engineering, University of South China, Hengyang, Hunan 421001, China.
authors.forename: Bo
authors.initials: B
authors.lastname: He
authors.forename: Lifu
authors.initials: L
authors.lastname: Liao
authors.forename: Xilin
authors.initials: X
authors.lastname: Xiao
authors.forename: Shuqin
authors.initials: S
authors.lastname: Gao
authors.forename: Yimou
authors.initials: Y
authors.lastname: Wu
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D015374:Biosensing Techniques / Q000295:instrumentation*; D049109:Cell Proliferation / Q000187:drug effects; D015169:Colony Count, Microbial / Q000295:instrumentation*; D004353:Drug Evaluation, Preclinical / Q000295:instrumentation; D055119:Elastic Modulus; D004867:Equipment Design; D019544:Equipment Failure Analysis; D064704:Levofloxacin; D008280:Magnetics / Q000295:instrumentation*; D045704:Mycoplasma genitalium / Q000187:drug effects* / Q000254:growth & development* / Q000302:isolation & purification; D015242:Ofloxacin / Q000008:administration & dosage*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013686:Telemetry / Q000295:instrumentation*; D013752:Tetracycline / Q000008:administration & dosage*
chemical_list: D000900:Anti-Bacterial Agents; D064704:Levofloxacin; D015242:Ofloxacin; D013752:Tetracycline