Solid phase indirect radioimmunoassay: standardization and applications in viral serology

16 Methods for Detecting Microbial Pathogens in Food and Water

Newly developed methods for the detection of bacteria and viruses have provided microbiologists with the means to rapidly identify and monitor specific microorganisms in food and water. Traditional methods of testing involve culture techniques to increase the numbers of the organism to a detectable level, followed by isolation and biochemical identification. This chapter focuses on the methodologies to detect pathogens and indicator organisms; however, the methods described are applicable to most bacteria. As detection and isolation methods have improved, a growing number of pathogens have been identified as important food- and waterborne pathogens. This chapter describes the use of nucleic acid and antibody probes that have the potential to circumvent the need to culture the organism prior to identification. Nucleic acid probes have become a valuable diagnostic reagent in the identification of human and animal pathogens and have made possible the identification of viruses and bacteria that are difficult, if not impossible, to cultivate. DNA probes have also proved to be a useful tool for identifying and monitoring the organisms in food and the environment.

Differentiation of foot-and-mouth disease virus strains using a competition enzyme-linked immunosorbent assay

Foot-and-mouth disease virus isolates were compared using solid-phase competition and indirect microenzyme-linked immunosorbent assays. Results were compared to those obtained from complement fixation tests. Similar relationships between the isolates were obtained using the indirect enzyme immunoassay and complement fixation tests. The competition assay was more discriminatory and the results did not always correlate with the other two assays.