Antibiotics and Enterohemorrhagic Escherichia coli (EHEC) Diarrhea

Controversy surrounds the use of antibiotics in the treatment of enterohemorrhagic Escherichia coli (EHEC) infections due to concerns about triggering hemolytic-uremic syndrome (HUS). The most common EHEC serotype causing human diseases worldwide is O157:H7.

Antibiotic therapy is generally NOT beneficial or recommended in patients with EHEC infection (particularly in children <10 years).

WHY? Several studies have shown increased induction of Shiga toxin with antibiotic therapy (i.e fluoroquinolones, trimethoprim-sulfamethoxazole, ampicillin). Shiga toxin is the major virulence factor of EHEC involved in the pathogenesis of HUS.

REFERENCES

1.  Holtz LR, Neill MA, Tarr PI  . 2009. Acute bloody diarrhea: a medical emergency for patients of all ages. Gastroenterology 136:1887–1898.
2. Smith KE, et al  . 2012. Antibiotic treatment of Escherichia coli O157 infection and the risk of hemolytic uremic syndrome, Minnesota. Pediatr. Infect. Dis. J. 31:37–41.
3. Tarr PI, Gordon CA, Chandler WL . 2005. Shiga-toxin-producing Escherichia coli and haemolytic uraemic syndrome. Lancet 365:1073–1086. 
4. Wong CS, Jelacic S, Habeeb RL, Watkins SL, Tarr PI  . 2000. The risk of the hemolytic-uremic syndrome after antibiotic treatment of Escherichia coli O157:H7 infections. N. Engl. J. Med. 342:1930–1936.
5.  Buchholz U, et al  . 2011. German outbreak of Escherichia coli O104:H4 associated with sprouts. N. Engl. J. Med. 365:1763–1770.
6. Bielaszewska, Martina et al.  Effects of Antibiotics on Shiga Toxin 2 Production and Bacteriophage Induction by Epidemic Escherichia coli O104:H4 Strain. Antimicrob. Agents Chemother. June 2012 vol. 56 no. 6 3277-3282.
7. Wong, C.S. et al. Risk factors for the hemolytic uremic syndrome in children infected with Escherichia coli O157:H7: a multivariable analysis. Clin Infect Dis. 2012;55(1):33.