Increasing incidence of resistance to nalidixic acid in shigellas from humans in England and Wales: implications for therapy.

Among shigellas isolated from patients in England and Wales in 2002, 10% of subgroups A, B and C, and 13% of subgroup D (Shigella sonnei), were resistant to nalidixic acid. As a consequence, should antimicrobial therapy be indicated, the efficacy of nalidixic acid as the preferred treatment for children with bacillary dysentery has been jeopardised.