Detection of Bacterial Pathogens in Different Matrices: Current Practices and Challenges

Abstract

Successful pathogen detection depends on analyst’s understanding of the nature of the matrix and the properties of the targeted microorganism. The matrix could be simple (e.g., drinking water) and easy to analyze for pathogens, or complex (e.g., fermented meat products or fecal samples) and requires an elaborate method to isolate the targeted microorganism. Some pathogens are recovered easily on common laboratory media but others may need time-consuming resuscitation on specialized media with incubation under strictly controlled conditions. Currently used methods for detecting pathogens rely on culture, immunological, genetic, and other techniques. These methods often include a preliminary step to amplify the pathogen’s population or a signal representing this microorganism. Enrichment is the most commonly used, but highly unpopular, technique to accomplish the amplification just described. In culture-based detection methods, the targeted pathogen is isolated from the enrichment using selective and differential media, then identified on the basis of multiple biochemical properties. Alternatively, the identification is accomplished by immunological or genetic techniques. Identification as commonly done does not prove the pathogenicity of the targeted organism, a deficiency that needs to be rectified in future detection methods. Rapid detection of pathogens in real time by means that are not destructive to the matrix is an idealistic goal that may materialize in near future.