Therapy of Mycobacterium abscessus Infections in Solid Organ Transplant Patients.

Mycobacterium abscessus complex (MABC), a rapidly growing Mycobacterium, is one of the most common causes of non-tuberculous mycobacteria (NTM) infections in the United States of America, and it has been associated with a wide spectrum of infections in immunocompetent and immunosuppressed individuals. Eradicating MABC is very challenging, even with prolonged combination therapies. The management of MABC infections in solid organ transplant (SOT) patients is usually complex given their net state of immunosuppression, associated comorbidities, and potential drug-drug interactions, among other things. In this manuscript, we discussed the antimicrobial management of pulmonary and extrapulmonary MABC infections. In addition, we reviewed promising novel therapies such as clofazimine, omadacycline, bedaquiline, and inhaled tigecycline that could join the existing antimicrobial armamentarium to fight this infection associated with significant morbidity and mortality. However, further studies are needed, especially among the immunocompromised host.

Nocardiosis in Solid Organ Transplant Recipients: 10-Year Single Center Experience and Review of Literature.

Solid organ transplant recipients (SOTRs) are at an increased risk of nocardiosis, a rare but life-threatening opportunistic infection. Universal PCP prophylaxis with trimethoprim-sulfamethoxazole (TMP-SMX) is used at our center, which is active in vitro against most species of the Nocardia genus and may have a role in preventing early infections. This is a single-center retrospective cohort study of nocardiosis in adult SOTRs at a large transplant center between January 2012 and June 2022, with comprehensive review of literature. Out of 6179 consecutive cases, 13 (0.2%) were diagnosed with nocardiosis. The patients were predominantly male (76.9%) and kidney transplant recipients (62%). Infection was diagnosed at median of 8.8 months (range, 3.7-98) after transplant. Patients were followed for a median of 457 days (range 8-3367). Overall mortality within one year after diagnosis was 46% (6/13), of which 17% (1/6) of deaths was attributable to Nocardia infection. No recurrence was reported. Nocardia infections were noted in a small proportion of our SOTRs and carried significant morbidity and mortality. TMP-SMX prophylaxis may be protective in some cases given low incidence of cases.