Mycobacterium abscessus infection in transplant recipients

Mycobacterium abscessus is a ubiquitous, rapidly growing mycobacterium that colonizes organic surfaces. It is a potential pathogen, especially in immunosuppressed patients, including transplant recipients in whom disease can range from localized cutaneous lesions to disseminated infections. The purpose of this study was to describe the 12-year impact from January 1997 to December 2009 of M. abscessus infection among solid organ and bone marrow transplantations performed in adults and children.

Information was obtained from the database of our Microbiology Department concerning samples, culture methods, and in vitro susceptibility testing. Isolates were classified as contaminants (C), colonization (CL), or disease (D) following standard criteria. We reviewed the medical records of affected subjects.

M abscessus was isolated in 76 patients (28 C, 18 CL, and 30 D), including 11 recipients, namely 8 (73%) classified as disease displaying 1 bone marrow case and solid organ cases--4 (50%) pulmonary (2 after cystic fibrosis), 2 renal, and 1 heart transplant patients. All were adults. The localization of infection showed 2 disseminated cases, both of whom shows cutaneous primary lesions, and 6 localized in 3 cases cutaneous and in 3, respiratory.

Diseases caused by M abscessus have increased in the last 5 years, possibly due to the greater number of transplants and the more focused search for the lesions. Most isolates were from lung cases, especially those with infections prior to transplantation. Respiratory and cutaneous samples were predominant, with skin lesions being an important site of primary symptom previous to dissemination of infection. Although the optimal regimen remains undefined, a favorable outcome depended mainly on a rapid diagnosis and inception of treatment following susceptibility test results.