MOLECULAR APPROACHES TO BACTERIAL DETECTION AND SPECIES SUBSPECIES CHARACTERIZATION - THE DIARRHEAGENIC ESCHERICHIA-COLI GROUPS/

Classical bacterial identification methods have worked well for defini ng most bacterial pathogens. Recent evidence, however, indicates that only some strains of a particular species are pathogenic (eg, the diar rheagenic classes of Escherichia coli) and that these pathogens cannot be identified by standard bacteriologic techniques. Molecular approac hes have been developed that serve as adjuncts to existing bacteriolog ic procedures for identifying pathogenic varieties within a species. T his short review is focused on defining the six classes of E. coli tha t cause different diarrheal disease syndromes and the best current mol ecular methods for identifying these pathogens from the background non pathogenic E. coli. identification of E. coli diarrheagenic pathogens with these molecular tools will ultimately allow for better definition of each pathogenic class and a clearer understanding of their relativ e importance in causing diarrheal diseases worldwide. In addition, we list several current applications of additional molecular methods that are useful in the epidemiologic study of enteric diseases.