Antibiotic therapy in Shiga toxin producing Escherichia coli infection and colonization

The post diarrheal hemolytic uremic syndrome (HUS) is a major complication of enteric infections with Shiga toxin producing (STEC). According to the present recommendations, antibiotic therapy of acute bloody diarrhea caused by STEC is generally discouraged. These recommendations are based on historically conflicting results describing the potential induction of HUS by antibiotic treatment during the early phase of infection with enterohemorrhagic O157 whereas no guidelines are available for the use of antibiotics in cases of already fully established HUS or in asymptomatic long term STEC carriers. In 2011, a large outbreak of hemorrhagic colitis complicated by HUS occurred in northern Germany caused by a STEC strain of serotype O104:H4 harbouring both a phage encoding Stx 2 as well as a plasmid mediated enteroaggregative phenotype. The majority of infections were observed in adults, complicated by the highest number of HUS cases ever encountered. Due to different newly introduced therapeutic strategies (e.g. complement blockade) antibiotic therapy was used in many patients once HUS was established. The outbreak therefore provided important new insights for the understanding of antibiotic therapy of STEC associated HUS in adults and for decolonization of long term STEC carriers. This review highlights new aspects concerning use of antibiotics in STEC infection and colonization.