Emergence of Penicillin Resistance in Recurrent Pneumococcal Endocarditis in an HIV-Infected Patient

The emergence of antibiotic resistance in Streptococcus pneumoniae poses a particular threat to HIV-infected patients. These patients are at increased risk of invasive pneumococcal disease and may respond poorly to pneumococcal vaccination. We describe an HIV-infected patient with recurrent aortic valve endocarditis due to the same serotype of S. pneumoniae (19A) despite appropriate treatment with penicillin and immunoprophylaxis. The pneumococcus responsible for the second episode of endocarditis was susceptible to cefotaxime (MIC of 0.06 microg/ml), but was no longer susceptible to penicillin (MIC of 0.25 microg/ml). The patient was treated successfully with 4 weeks of intravenous ceftriaxone.