A rapid method for determination of in vitro susceptibility to antibiotics with a bulk acoustic wave bacterial growth biosensor.

A novel bulk acoustic wave (BAW) bacterial growth biosensor was developed to study in vitro susceptibility by continuous monitoring of disturbances of bacterial growth at low antibiotic concentrations, followed by the accurate and rapid estimation of growth kinetic parameters and minimum inhibitory concentrations (MICs). The susceptibilities of bacteria, e.g. Escherichia coli, Staphylococcus aureus, Proteus vulgaris, Pr. morganii and Pr. mirabilis, to various antibiotics, e.g. penicillin, streptomycin, gentamicin and cefotaxime, were investigated, respectively, and the MICs were rapidly determined with a higher reproducibility than the conventional broth micro-dilution technique (BMDT). The effects of cell constant of conductivity electrode, pH and temperature on bacterial growth and biosensor signals were discussed in detail. The proposed method offers an effective alternative to the conventional methods.