Treatment failure in Haemophilus influenzae due to a beta-lactamase low-level ampicillin-resistant organism

Haemophilus influenzae is a rare causative organism of vertebral osteomyelitis in an adult. Cases reported in the literature were mainly caused by ampicillin-susceptible type b strains. Here we describe the first case of vertebral osteomyelitis due to a non-typeable, beta-lactamase low-level ampicillin-resistant H. influenzae strain with failure of prolonged intravenous amoxicillin treatment.