Why should antibiotics be used with caution in suspected STEC infections?

• A. Antibiotics may trigger increased Shiga toxin production and risk of HUS; supportive care is preferred in many cases
• B. Antibiotics reduce risk of HUS but can cause resistance
• C. Antibiotics may cause antibiotic resistance but are always beneficial
• D. Antibiotics have no effect on Shiga toxin production

Answer: (C)

Antibiotics can trigger Shiga toxin production in Shiga toxin–producing E. coli, because the toxin genes are carried on a phage that can be induced when the bacterial SOS response is activated by certain antibiotics. This can increase toxin release and raise the risk of hemolytic uremic syndrome, so in suspected STEC infections the preferred approach is supportive care rather than routine antibiotic therapy, especially in children. The idea that antibiotics are always beneficial or have no effect on toxin production isn’t correct, and claims that antibiotics merely reduce HUS risk ignore the real possibility of toxin induction and worse outcomes.