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July 15, 1974

Haemophilus influenzae Type B Resistant to Ampicillin: A Report of Two Cases

Author Affiliations

From the Microbiology Section, Research Foundation (Mr. Khan and Drs. Ross and Rodriguez) and Clinical Bacteriology Laboratory (Mr. Controni), Children's Hospital National Medical Center, and the Microbiology Department, Georgetown University Schools of Medicine and Dentistry (Drs. Rodriguez and Saz), Washington, DC.

JAMA. 1974;229(3):298-301. doi:10.1001/jama.1974.03230410022016

Recently, two infants with severe infections due to ampicillin-resistant strains of Haemophilus influenzae type B were treated at Children's Hospital National Medical Center. In both cases, it was necessary to change therapy to chloramphenicol. One patient with meningitis died while the second with bacteremia and pneumonia recovered. A survey of 60 recent isolates of H influenzae type B in the Washington community showed that 10% were ampicillin-resistant. The enzyme produced by these resistant strains was found to be a β-Iactamase. Careful appraisal is now necessary to decide whether ampicillin is the drug of choice as initial therapy in H influenzae meningitis in pediatric patients.

(JAMA 229:298-301, 1974)