PATHOGENESIS AND DIAGNOSIS OF SHIGA TOXIN-PRODUCING ESCHERICHIA-COLI INFECTIONS

Since their initial recognition 20 years ago, Shiga toxin-producing Es cherichia coli (STEC) strains have emerged as an important cause of se rious human gastrointestinal disease which may result in life-threaten ing complications such as hemolytic-uremic syndrome. Food-borne outbre aks of STEC disease appear to be increasing and when mass-produced and mass-distributed foods are concerned, can involve large numbers of pe ople. Development of therapeutic and preventative strategies to combat STEC disease requires a thorough understanding of the mechanisms by w hich STEC organisms colonize the human intestinal tract and cause loca l and systemic pathological changes. While our knowledge remains incom plete, recent studies have improved our understanding of these process es, particularly the complex interaction between Shiga toxins and host cells, which is central to the pathogenesis of STEC disease. In addit ion, several putative accessory virulence factors have been identified and partly characterized. The capacity to limit the scale and severit y of STEC disease is also dependent upon rapid and sensitive diagnosti c procedures for analysis of human samples and suspect vehicles. The i ncreased application of advanced molecular technologies in clinical la boratories has significantly improved our capacity to diagnose STEC in fection early in the course of disease and to detect low levels of env ironmental contamination.. This, in tom, has created a potential windo w of opportunity for future therapeutic intervention.