No abstract

No abstract

Ultrasonic cavitation was employed to enhance sensitivity of bacterial spore immunoassay detection, specifically, enzyme-linked immunosorbent assay (ELISA) and resonant mirror (RM) sensing. Bacillus spore suspensions were exposed to high-power ultrasound in a tubular sonicator operated at 267 kHz in both batch and flow modes. The sonicator was designed to deliver high output power and is in a form that can be cooled efficiently to avoid thermal denaturation of antigen. The 30-s batch and cooled flow (0.3 mL/min) sonication achieved an approximately 20-fold increase in ELISA sensitivity compared to unsonicated spores by ELISA. RM sensing of sonicated spores achieved detection sensitivity of approximately 10(6) spores/mL, whereas unsonicated spores were undetectable at the highest concentration tested. Improvements in detection were associated with antigen released from the spores. Equilibrium temperature increase in the tubular sonicator was limited to 14 K after 30 min and was maintained for 6 h with cooling and flow (0.3 mL/min). The work described here demonstrates the utility of the tubular sonicator for the improvement in the sensitivity of the detection of spores and its suitability as an in-line component of a rapid detection system.

This chapter is a brief introduction to pathogenic microorganisms and also discusses virulence factors. An understanding of virulence factors is important, as they represent potential targets for the detection of microbial pathogens. Sources and routes of infection are also briefly discussed with reference to specific examples. There are a number of ways in which infection could be acquired, including via contaminated food and water; hospital acquired infection; "naturally acquired" infection; and intentional infection, for example, through the use of biological warfare agents. The focus of the review is predominantly on human pathogens. However, there are a range of other microbial pathogens of particular importance in other areas; for example, animal and plant pathogens, which will not be discussed. Finally, a brief overview of the detection of pathogenic bacteria is presented.