Wu, Yifan. Rapid and dynamic detection of antimicrobial response of pathogenic bacteria using MZO nanostructure-modified quartz crystal microbalance. Retrieved from https://doi.org/doi:10.7282/t3-t057-h668
DescriptionAntimicrobial resistance (AMR) threatens the effective prevention and treatment of a constantly increasing range of infections caused by bacteria, parasites, viruses and fungi, and has caused a dramatic increase in infection-related deaths, such that it threatens to become the next world pandemic. We report a magnesium zinc oxide nanostructure (MZOnano) modified quartz crystal microbalance (QCM) biosensor for rapid and dynamic detection of AMR. The sensor consists of a QCM with MZOnano grown directly on the sensing electrode using metalorganic chemical vapor deposition (MOCVD). The MZOnano sensing surface offers high-sensitivity to various biological species through surface-wettability and morphology control. Combining advantages of MZOnano with the QCM dynamic impedance spectrum makes the biosensor well-suited for monitoring viscoelastic transitions during drug treatment compared to the conventional frequency shift signals from the QCM. Using the MZOnano-QCM, we demonstrated the dynamic real-time monitoring of culture growth and antimicrobial treatment effects on two clinically relevant bacterial strains: (1) Gram-positive strain Staphylococcus epidermidis and (2) Gram-negative strain Pseudomonas aeruginosa. The antimicrobial treatment response of each of the two bacterial strains using Ciprofloxacin as the drug, was rapidly and dynamically detected. The standard microbiological protocols and assays were performed to determine the optimal drug dosages and the minimum inhibitory concentration to serve as the benchmark for the data reported by the sensors. The sensor also demonstrated capability to rapidly (within 1.5 hours) detect dosage dependent response of the two bacterial strains in real time. The testing results from two clinically-relevant bacterial strains mentioned above demonstrate the capabilities of the MZOnano - QCM to sense both mass accumulation and viscoelastic transitions during cell growth and drug treatment. It is found that the viscoelastic transitions of the bacterial cells during drug treatment gives higher sensitivity to the data as compared to the frequency shift signals of the device.