Frequent exacerbation of pulmonary nocardiosis during maintenance antibiotic therapies in a hematopoietic stem cell transplant recipient.

We describe a rare case of recurrent pulmonary nocardiosis (PN) in a hematopoietic stem cell transplant recipient. The patient developed Nocardia farcinica infection while receiving corticosteroid and cyclosporine for the treatment of bronchiolitis obliterans, probably due to chronic graft-versus-host disease (cGVHD). The patient responded well to the initial treatment with meropenem, but PN recurred 3 times during oral maintenance therapies using different antibiotics, which were chosen on the basis of the results of in vitro susceptibility testing against N farcinica Minocycline, amoxicillin/clavulanate, and levofloxacin were not effective as oral maintenance therapies. Frequent exacerbation of PN was considered to have resulted from the low blood concentration of these antibiotics, and decreased gastrointestinal absorption, probably due to cGVHD, might have been the underlying problem.