Rapid Detection of Staphylococcus Aureus Using a Separated Electrode Piezoelectric Crystal Sensor

A rapid, non-destructive method for the determination of Staphylococcus epidermidis adhesion to surfaces using quartz crystal resonant sensor technology

AIMS

To investigate the use of quartz crystal resonant sensor (QCRS) technology to determine the adhesion of Staphylococcus epidermidis to fibronectin-coated surfaces.

METHODS AND RESULTS

QCRS sensors (14 MHz) with 4 mm gold electrodes were coated with fibronectin and exposed for 15 min to suspensions of Staph. epidermidis ranging in concentration from 1 x 10(2) to 1 x 10(6) cfu ml(-1). Changes in resonant frequency were recorded and showed a linear relationship with the logarithm of cell concentration over the range tested.

CONCLUSIONS

QCRS technology was shown to be a rapid, sensitive and non-destructive method for measuring the adhesion of bacteria to surfaces.

SIGNIFICANCE AND IMPACT OF THE STUDY

This report demonstrates that QCRS technology has the potential to be used for a range of applications requiring measurement of bacteria on surfaces. In particular, it may be used for the real-time monitoring of bacterial biofilm formation.

Detection of staphylococcal enterotoxin B employing a piezoelectric crystal immunosensor

This paper reports on a study concerning the development of a biochemical sensor for Staphylococcal Enterotoxin B (SEB), a substance within the bracket of biological warfare. A 20 MHz piezoelectric quartz crystal sensor device was employed in a flow injection system. The assay for SEB is based on a competition scheme using polyclonal antibodies (anti-SEB). Three parameters, i.e. the flow rate in the flow cell, the incubation time and the anti-SEB concentration, were optimized. A detection limit of 0.1 microgram/ml was obtained, whereas at concentrations of SEB of 10 micrograms/ml or higher the sensor response was completely inhibited. The results were compared with a competition enzyme linked immunosorbent assay.