Multiple drug-resistance in Shigella flexneri isolated from a patient with human immunodeficiency virus.

Persistent shigellosis, due to Shigella flexneri resistant to multiple antibiotics, developed in a 40-yr-old homosexual man with human immunodeficiency virus infection. The Shigella strain demonstrated resistance to ampicillin, tetracycline, and trimethoprim-sulfamethoxazole. Although Shigella flexneri isolates resistant to trimethoprim-sulfamethoxazole are uncommon in the United States, laboratories should monitor resistance patterns through routine in vitro susceptibility testing.