Shiga toxin-induced Haemolytic Uraemic Syndrome and the role of antibiotics

Summary Objectives The administration of antibiotics in infections caused by Shiga toxin producing E. coli (STEC) strains, such as O157:H7, was and remains controversial, as it has been associated with the development of haemolytic uraemic syndrome (HUS). We conducted a literature review to better examine this association. Methods We searched the PubMed and Google Scholar databases for relevant articles, using the key words: ``haemolytic uraemic syndrome'', ``Shiga toxin'', `` E. coli O157:H7'', `` E. coli O104:H4'', ``STEC colitis'', ``STEC antibiotics'', ``STEC fosfomycin'', ``STEC trimethoprim sulfamethoxazole'', ``STEC fluoroquinolones'', ``STEC ciprofloxacin'', ``STEC rifaximin'', ``STEC gentamycin'', ``STEC colistin'', “Shiga toxin binding agent”, “Shiga toxin monoclonal antibody” and ``STEC Japan epidemic''. Results Numerous studies report that antibiotics increase the risk of HUS development, while others report that antibiotics do not have any effect or can even reduce the rate of HUS development in STEC infections. The infecting STEC strain, the type of antibiotic as well as the timing of its administration appear to significantly affect the development of HUS in a STEC infected patient. Conclusions It appears that, while some antibiotics such as b-lactams and TMP/SMX may be detrimental, others appear to be safe and can prevent the development of HUS. Of note, fosfomycin appears to be the antibiotic with the most positive results from clinical studies, and may be able to avert HUS development, especially if administered within the first two or three days from diarrhoea onset. Fluoroquinolones have also shown positive outcomes in clinical studies, despite demonstrating unfavourable results in in vitro studies. Other agents, such as colistin, gentamycin and rifamycins, have shown promising results in in vitro studies and require further evaluation.