Successful treatment of disseminated Nocardia farcinica infection in a living-donor liver transplantation recipient

Case report: Nocardia farcinica pneumonia in early-stage post liver transplantation

Background

Liver transplantation is a well-established treatment for end-stage liver disease. The evolution of immunosuppressants has supported the recent advances in this field. However, this leads to immunosuppression and increases the risk for infections. Nocardia is an aerobic gram-positive bacillus, which can cause multi-systemic or multi-organ infections. Nocardia is an opportunistic pathogen that principally affects immunosuppressed patients.

Case presentation

Herein, we present a case of Nocardia farcinica pneumonia in a patient at early-stage post-liver transplantation. Following appropriate microbiological tests and imaging, the diagnosis was finally confirmed. A full recovery was achieved after optimal antibiotic therapy of sulfamethoxazole, minocycline, and amikacin.

Conclusions

Nocardia farcinica pneumonia is a rare and life-threatening disease, especially in patients after liver transplantation. Imaging and microbiological tests are helpful for the early diagnosis of the disease. Trimethoprim-sulfamethoxazole (TMP-SMX) as part of first-line therapy for nocardiosis is recommended.

Nocardia farcinica brain abscess: epidemiology, pathophysiology, and literature review

BACKGROUND

Infections caused by Nocardia farcinica are potentially lethal because of the organism's tendency to disseminate and resist antibiotics. Central nervous system involvement has been documented in 30% of infections caused N. farcinica.

METHODS

Case report and review of the literature.

RESULTS

A case of primary brain abscess caused by N. farcinica, identified by 16SrRNA sequencing, is presented, and 39 cases reported previously in the literature are reviewed. Our patient underwent a neuronavigation-guided right frontal craniotomy and was treated with trimethoprim/sulfamethoxazole and amoxicillin-clavulanic acid for 12 mo. He showed marginal improvement in his prior left hemiparesis at the last review 14 months later.

CONCLUSION

Cases of N. farcinica infections are being reported increasingly because of recent changes in taxonomy and diagnostic methodology. This change in epidemiology has implications for therapy because of the organism's pathogenicity and natural resistance to multiple antimicrobial agents, including third-generation cephalosporins. Any delay in starting appropriate antibiotic therapy can have adverse consequences.

High-resolution CT findings of patients with pulmonary nocardiosis

BACKGROUND

Opportunistic pulmonary infection with Nocardia species is rare in humans, and only a few studies have radiologically analyzed patients with pulmonary nocardiosis using high-resolution computed tomography (HRCT).

METHODS

We retrospectively reviewed the medical records of patients with pulmonary nocardiosis at our hospital between April 2006 and December 2011 to assess HRCT and clinical findings. We also searched the medical literature for pulmonary nocardiosis reported in Japan between 2002 and 2011 for comparison.

RESULTS

We identified seven patients at our institution and 33 reported infections in Japan. Four of our patients were immunocompetent, whereas the other three had impaired cellular immunity due to type 2 diabetes mellitus or having been inappropriately treated with steroid. Thoracic HRCT revealed no zonal predominance, but tropism for distribution from the middle to the peripheral area, and radiological findings of nodules, cavitation, mass, consolidations, bronchial wall thickening, septal line thickening and ground glass opacity (GGO) were evident. The main HRCT finding in our study comprised nodules (n=5, 71.4%) <30 mm and four patients had multiple nodules as described in other reports. Furthermore, we discovered a crazy paving appearance (CPA) around nodules, cavities, masses or consolidations in five patients (71.4%).

CONCLUSIONS

Multiple nodules distributed from the middle to the peripheral area on HRCT might reflect pulmonary nocardiosis, and CPA seemed to be a worth paying attention to the diagnosis.

Update and actual trends on bacterial infections following liver transplantation

Recent advances in effective antimicrobial prophylactic strategies have led to a decline in the incidence of opportunistic infections in liver transplant recipients. However, morbidity and mortality due to infectious diseases remain as major problems. Bacterial infections occurring early after transplant are mainly related to the technical aspects of the procedure. By contrast, after the first postoperative days and beyond, the nature and variety of infectious complications change. Opportunistic bacterial infections are uncommon after 6 mo in patients receiving stable and reduced maintenance doses of immunosuppression with good graft function and little is documented about these cases in the literature. Transplant recipients may be more susceptible to some pathogens, such as the Nocardia species, Legionella species, Listeria monocytogenes, Mycoplasma species, Salmonella species or Rhodococcus equi. Respiratory infections due to capsulated bacteria, such as Streptococcus pneumoniae and Haemophilus influenza, can be life-threatening if not promptly treated in this population. These late bacterial infections may be very difficult to recognize and treat in this population. In this article, we review what has been described in the literature with regards to late bacterial infections following liver transplantation.

Disseminated subcutaneous nocardiosis caused by Nocardia farcinica diagnosed by FNA biopsy and 16S ribosomal gene sequencing

Nocardia is an infrequent but significant cause of infections in the immunocompromised host. Clinical syndromes are varied and ranges from pulmonary, disseminated, cutaneous, and CNS involvement. Here we describe a case of disseminated subcutaneous nodules in a patient with multiple myeloma caused by Nocardia farcinica. The diagnosis was made by FNA biopsy which revealed gram positive filamentous bacilli in background of acute inflammation on smears. This was confirmed by 16S ribosomal gene sequencing. Prompt identification of N. farcinica is important because of its intrinsic resistance to broad spectrum cephalosporins and high risk of dissemination.