INFECTIONS WITH VEROTOXIN-PRODUCING ESCHERICHIA COLI O157:H7 AND OTHER SEROTYPES, INCLUDING THE OUTBREAK STRAIN O104:H4

Through the acquisition of mobile genetic elements, the normally harmless commensal Escherichia coli evolved into a highly adapted human pathogen. Pathogenic strains of E. coli are associated with urinary tract infections, sepsis/meningitis, and diarrhoea. At least six different diarrhoeagenic E. coli pathotypes have emerged during the past three decades as human pathogens of public health importance worldwide. In this review, we focus on the clinical features, pathogenic mechanisms, and diagnostic strategies of verotoxin-producing E. coli (VTEC) that are associated with sporadic cases and epidemics of gastrointestinal disease throughout the world. Recently, an E. coli strain of serotype O104:H4 combining verotoxin production with virulence factors of another pathotype, the enteroaggregative E. coli (EAEC), emerged as the cause of a severe outbreak in Europe.