Pulmonary nocardiosis in heart transplant recipients: treatment and outcome

Updated Review on Nocardia Species: 2006-2021

This review serves as an update to the previous Nocardia review by Brown-Elliott et al. published in 2006 (B. A. Brown-Elliott, J. M. Brown, P. S. Conville, and R. J. Wallace. Jr., Clin Microbiol Rev 19:259-282, 2006, https://doi.org/10.1128/CMR.19.2.259-282.2006). Included is a discussion on the taxonomic expansion of the genus, current identification methods, and the impact of new technology (including matrix-assisted laser desorption ionization-time of flight [MALDI-TOF] and whole genome sequencing) on diagnosis and treatment. Clinical manifestations, the epidemiology, and geographic distribution are briefly discussed. An additional section on actinomycotic mycetoma is added to address this often-neglected disease.

Nocardia infections in solid organ transplantation: Guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of Nocardia infections after solid organ transplantation (SOT). Nocardia infections have increased in the last two decades, likely due to improved detection and identification methods and an expanding immunocompromised population. The risk of developing nocardiosis after transplantation varies with the type of organ transplanted and the immunosuppression regimen used. Nocardia infection most commonly involves the lung. Disseminated infection can occur, with spread to the bloodstream, skin, or central nervous system. Early recognition of the infection and initial appropriate treatment is important to achieve good outcomes. Species identification and antimicrobial susceptibility testing are strongly recommended, as inter- and intraspecies susceptibility patterns can vary. Sulfonamide is the first-line treatment of Nocardia infections, and combination therapy with at least two antimicrobial agents should be used initially for disseminated or severe nocardiosis. Trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis may be helpful in preventing Nocardia infection after SOT.

Infections in Heart, Lung, and Heart-Lung Transplantation

Half a century has passed since the first orthotopic heart transplant took place. Surgical innovations allowed for heart, lung, and heart-lung transplantation to save lives of patients with incurable chronic cardiopulmonary conditions. The complexity of the surgical interventions, chronic host health conditions, and antirejection immunosuppressive medications makes infectious complications common. Infections have remained one of the main barriers for successful transplantation and a source of significant morbidity and mortality. Recognition of infections and its management in this setting require outstanding clinical skills since transplant recipients may not exhibit classic signs or symptoms of disease, and laboratory work has some pitfalls. The prevention, identification, and management of infectious diseases complications in this population are a priority to undertake to improve the medical outcomes of transplantation. Herein, we reviewed the historical aspects, epidemiology, and prophylaxis of infections in heart, lung, and heart-lung transplantation. We also discuss the most prevalent organisms affecting the host and the organ systems involved.

Sporotrichoid Skin Infection Caused by Nocardia brasiliensis in a Kidney Transplant Patient

Prompt and accurate diagnosis of Nocardia skin infections is important in immunocompromised hosts, especially transplant patients. The sporotrichoid form, which is otherwise known as the lymphocutaneous form of Nocardia skin involvement, can mimic other conditions, including those caused by fungi, mycobacteria, spirochetes, parasites and other bacteria. Delayed or inaccurate diagnosis and treatment of Nocardia skin infections in transplant patients could lead to dissemination of disease and other poor outcomes. Nocardia brasiliensis is a rare cause of lymphocutaneous nocardiosis in solid organ transplant patients with only two other cases reported to our knowledge. This case describes a middle-aged man, who presented 16 years post kidney transplant. He developed a sporotrichoid lesion on his upper extremity one week after gardening. Ultrasound showed a 35-cm abscess tract on his forearm, which was subsequently drained. Nocardia brasiliensis was isolated from pus culture and he was treated successfully with amoxicillin/clavulanate for 6 months. A review of the relevant literature is included.

Nocardia infections in the transplanted host

BACKGROUND

Nocardia are uncommon pathogens that disproportionately afflict the immunocompromised host. Epidemiology and outcome data of Nocardia infections in transplant recipients are limited.

METHODS

We performed a retrospective chart review of all patients at Duke University Hospital with a history of solid organ transplant (SOT) or hematopoietic cell transplant (HCT) and at least one positive culture for Nocardia between 1996 and 2013. Our aim was to describe the epidemiology and outcomes of Nocardia infections in the transplanted host.

RESULTS

During the 18-year study period, 51 patients (14 HCT and 37 SOT recipients) had Nocardia infection. Nocardia incidence was stable during the study period in all populations except heart transplants, whose incidence declined. Infection occurred earlier in the HCT group than the SOT group (median time to diagnosis of 153 and 370 days, respectively). In both groups, the most common site involved was the lung. Outcomes were overall poor, especially in the HCT group with a cure rate of 29%. Heart transplant recipients had significantly better overall survival (P < .05) than other patients. Trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis did not provide complete protection from Nocardia infections, nor did it appear to select for resistant Nocardia isolates.

CONCLUSIONS

Infections with Nocardia are typically a late post-transplant complication. The use of TMP-SMX prophylaxis was not associated with TMP-SMX-resistant Nocardia. Overall outcomes remain poor.

Relationship between the duration of trimethoprim/sulfamethoxazole treatment and the clinical outcome of pulmonary nocardiosis

BACKGROUND

Despite treatment, pulmonary nocardiosis, which is a rare opportunistic disease caused by Nocardia species, has poor clinical outcomes including recurrence and death. Currently, the treatment regimen and duration for pulmonary nocardiosis are not fully understood. The present study aimed to clarify the factors related to the clinical outcome of pulmonary nocardiosis.

METHODS

The medical records of 24 patients with pulmonary nocardiosis were retrospectively reviewed. The patients were divided into two groups based on the outcomes within 2 years: patients with controlled disease (n = 14) and patients who developed recurrence or died (n = 10).

RESULTS

Nocardia was identified by 16S ribosomal RNA sequencing in 17 patients (70.8%) and by conventional biochemical test in five patients (20.8%). The patients' characteristics, clinical findings, radiological features, and treatment history were not different between the two groups. Compared with patients who developed recurrence or died, those with controlled disease had significantly longer total duration of treatment with antibiotics, especially trimethoprim/sulfamethoxazole (67.5 ± 111.6 days vs. 9.0 ± 6.5 days; p = 0.01). Pancytopenia was the most frequent adverse effect of trimethoprim/sulfamethoxazole.

CONCLUSIONS

Longer duration of trimethoprim/sulfamethoxazole treatment was significantly associated with better outcomes of pulmonary nocardiosis. In such cases, antibiotics, especially trimethoprim/sulfamethoxazole, should be administered for more than 3 months.

Nocardiosis in the south of France over a 10-years period, 2004-2014

BACKGROUND

Nocardiosis is a rare disease with polymorphic presentations. The epidemiology and clinical presentation could change with the increasing number of immunocompromised patients.

METHODS

The medical records and microbiological data of patients affected by nocardiosis and treated at the university hospitals of Marseille between 2004 and 2014 were analyzed retrospectively.

RESULTS

The cases of 34 patients infected by Nocardia spp during this period were analyzed. The main underlying conditions were transplantation (n=15), malignancy (n=9), cystic fibrosis (n=4), and immune disease (n=3); no immunodeficiency condition was observed for three patients. No case of AIDS was observed. At diagnosis, 61.8% had received steroids for over 3 months. Four clinical presentations were identified, depending on the underlying condition: the disseminated form (50.0%) and the visceral isolated form (26.5%) in severely immunocompromised patients, the bronchial form (14.7%) in patients with chronic lung disease, and the cutaneous isolated form (8.8%) in immunocompetent patients. Nocardia farcinica was the main species identified (26.5%). Trimethoprim-sulfamethoxazole was prescribed in 68.0% of patients, and 38.0% underwent surgery. Mortality was 11.7%, and the patients who died had disseminated or visceral nocardiosis.

CONCLUSIONS

The clinical presentation and outcome of nocardiosis depend on the patient's initial immune status and underlying pulmonary condition. Severe forms were all iatrogenic, occurring after treatments altering the immune system.

Immunosuppression and a serious opportunistic infection: an unfortunate price to pay

A 57-year-old woman with diabetes mellitus type 1, status postcadaveric pancreas transplant alone 11 years ago, on chronic immunosuppression, and dialysis-dependent end-stage renal disease, presented with 2 months of progressive generalised weakness, lumbar back pain with right lower extremity radiculopathy and episodic symptomatic hypotension. Preliminary infectious disease work up was unremarkable. She was discharged following symptomatic improvement. She represented 3 days later with continued functional decline and leucocytosis. Chest X-ray demonstrated diffuse pulmonary nodules, confirmed on chest CT scan. CT-guided biopsy of a right upper lobe nodule was performed; studies confirmed Nocardia farcinica. Further imaging revealed bilateral white matter intracranial lesions, and extensive Nocardia-positive fluid collections in the right gluteal and vastus musculature, requiring periodic surgical debridement. She was treated with multiple antimicrobials, including trimethoprim-sulfamethoxazole, amoxicillin/clavulanate and moxifloxacin. She was discharged after a 6-month hospitalisation.

Nocardiosis in transplant recipients

Nocardiosis is a rare opportunistic infection caused by Nocardia spp., an aerobic actinomycete, that mainly affects patients with cell-mediated immunity defects, such as transplant recipients. Despite recent progress regarding Nocardia identification and changes in taxonomic assignment, many challenges remain for the diagnosis or management of nocardiosis. This opportunistic infection affects 0.04 to 3.5 % of patients with solid organ or hematopoietic stem cell transplantation, depending on the organ transplanted, cytomegalovirus (CMV) infection, corticosteroids dose and calcineurin inhibitors level. Nocardiosis diagnosis relies on appropriate clinical, radiological and microbiological workup that includes the sampling of an accessible involved site and molecular microbiology tools. In parallel, extensive clinical and radiological evaluations are mandatory, including brain imaging, even in the absence of neurological signs. In transplanted patients, differential diagnosis is challenging, with co-infections reported in 20 to 64 % of cases. As the antibiotic susceptibility pattern varies among species, the antimicrobial regimen before species identification should rely on the association of antibiotics active on all species of Nocardia. Bactericidal antibiotics are required in cases of severe or disseminated disease. Furthermore, in transplant recipients, combination therapy is difficult to manage because of cumulative toxicity and interactions with immunosuppressive agents. Because of a high recurrence rate, antibiotic therapy should be prescribed for 6 to 12 months.

Functional diversity of Nocardia in metabolism

Bacteria affiliated in the genus Nocardia are aerobic and Gram-positive actinomycetes that are widely found in aquatic and terrestrial habitats. As occasional pathogens, several of them cause infection diseases called 'nocardiosis' affecting lungs, central nervous system, cutaneous tissues and others. In addition, members of the genus Nocardia exhibit an enormous metabolic versatility. On one side, many secondary metabolites have been isolated from members of this genus that exhibit various biological activities such as antimicrobial, antitumor, antioxidative and immunosuppressive activities. On the other side, many species are capable of degrading or converting aliphatic and aromatic toxic hydrocarbons, natural or synthetic polymers, and other widespread environmental pollutants. Because of these valuable properties and the application potential, Nocardia species have attracted much interest in academia and industry in recent years. A solid basis of genetic tools including a set of shuttle vectors and an efficient electroporation method for further genetic and metabolic engineering studies has been established to conduct efficient research. Associated with the increasing data of nocardial genome sequences, the functional diversity of Nocardia will be much faster and better understood.

Fungal infection in heart transplant recipients with severe sepsis: single-center experience

The objective of this study was to describe in heart transplant recipients severe sepsis due to fungal infection, which is associated with high mortality. This was a retrospective study including 366 patients who underwent heart transplantation from 1987 to 2009 in whom severe sepsis due to fungal infection developed, with multiple-organ failure. Sepsis was diagnosed on the basis of a positive culture for the infective agent, such as Cryptococcus, Aspergillus, Candida, or Nocardia, from an appropriate source such as blood, wound, or sputum. In 10 patients, severe sepsis due to fungal infection was treated temporally by reducing or sparing immunosuppression; 7 of these patients survived after intensive care. Only 1 patient required pulsed therapy because of an acute rejection episode. Early diagnosis with aggressive diagnostic techniques and use of combination therapy must be considered to reduce the risk of death in heart transplant recipients with fungal infection.

Changing trends in infectious disease in heart transplantation

BACKGROUND

During the past 25 years, advances in immunosuppression and the use of selective anti-microbial prophylaxis have progressively reduced the risk of infection after heart transplantation. This study presents a historical perspective of the changing trends of infectious disease after heart transplantation.

METHODS

Infectious complications in 4 representative eras of immunosuppression and anti-microbial prophylaxis were analyzed: (1) 38 in the pre-cyclosporine era (1978-1980), (2) 72 in the early cyclosporine era (1982-1984), where maintenance immunosuppression included high-dose cyclosporine and corticosteroid therapy; (3) 395 in the cyclosporine era (1988-1997), where maintenance immunosuppression included cyclosporine, azathioprine, and lower corticosteroid doses; and (4) 167 in the more recent era (2002-2005), where maintenance immunosuppression included cyclosporine and mycophenolate mofetil.

RESULTS

The overall incidence of infections decreased in the 4 cohorts from 3.35 episodes/patient to 2.03, 1.35, and 0.60 in the more recent cohorts (p < 0.001). Gram-positive bacteria are emerging as the predominant cause of bacterial infections (28.6%, 31.4%, 51.0%, 67.6%, p = 0.001). Cytomegalovirus infections have significantly decreased in incidence and occur later after transplantation (88 +/- 77 days, pre-cyclosporine era; 304 +/- 238 days, recent cohort; p < 0.001). Fungal infections also decreased, from an incidence of 0.29/patient in the pre-cyclosporine era to 0.08 in the most recent era. A major decrease in Pneumocystis jiroveci and Nocardia infections has also occurred.

CONCLUSIONS

The overall incidence and mortality associated with infections continues to decrease in heart transplantation and coincides with advances in immunosuppression, the use of selective anti-microbial prophylaxis, and more effective treatment regimens.

Nocardiosis at the turn of the century

Nocardia species is an uncommon pathogen that affects both immunosuppressed and immunocompetent patients. The clinical and microbiologic spectrum of nocardiosis has changed recently due to the widespread use of cotrimoxazole prophylaxis, the emergence of new types of immunosuppressed patients, and the improved identification of isolates using molecular techniques. Nocardia asteroides was traditionally considered the predominant organism, and prophylaxis with cotrimoxazole was considered almost universally protective. We conducted the current study to determine the incidence of nocardiosis and its microbiologic and clinical characteristics in a general hospital over the last 12 years. We reviewed the clinical records of all patients in whom Nocardia species was isolated from clinical specimens between 1995 and 2006. Nocardia isolates were identified by standard procedures and by 5' end 16S rRNA gene polymerase chain reaction (PCR) and sequencing. Susceptibility to cotrimoxazole, minocycline, imipenem, linezolid, and amikacin was determined by the broth microdilution method following the guidelines of the Clinical and Laboratory Standards Institute.The incidence of Nocardia infections did not increase significantly during the study period (0.39/100,000 inhabitants in 1995-1998 and 0.55/100,000 inhabitants in 2003-2006). Nocardia was recovered from 43 patients. Six were considered to be colonized. The colonizing species were N. farcinica, N. nova, and N. asteroides. All colonized patients had severe underlying pulmonary conditions and were treated with antimicrobials (6 patients) or corticosteroids (4 patients). Invasive nocardiosis was diagnosed in 37 patients (86.5% were men, and their mean age was 55.8 +/- 17.3 yr). The most common underlying condition in our institution was human immunodeficiency virus (HIV) infection (10 patients; 27%), followed by chronic obstructive pulmonary disease (8 patients; 21.6%), autoimmune diseases (8 patients; 21.6%), solid organ transplantation (7 patients; 18.9%), and cancer (4 patients; 10.8%). The most important risk factor for nocardiosis was corticosteroid administration (23 patients; 62.2%). Nocardiosis affected the lungs in 26 cases (70.3%), the skin in 3 cases (8.1%), and the central nervous system in 2 cases (5.4%). It was disseminated in 5 cases (13.5%) and caused otomastoiditis in 1 (2.7%). The species identified were N. cyriacigeorgica (32.4%), N. farcinica (24.3%), N. otitidiscaviarum (10.8%), N. veterana (8.1%), N. nova (5.4%), N. abscessus (5.4%), N. asiatica (2.7%), N. beijingensis (2.7%), N. brasiliensis (2.7%), N. carnea (2.7%), and Nocardia species (2.7%).Linezolid and amikacin were uniformly active against all the isolates, whereas 29.7% of isolates showed intermediate susceptibility to minocycline (minimum inhibitory concentration = 2 mg/L), 10.8% were resistant to cotrimoxazole, and 5.4% were resistant to imipenem. Nocardiosis occurred while the patients were on cotrimoxazole prophylaxis in 8 cases (21.6%). The strains isolated from these patients were susceptible to cotrimoxazole in 5 cases (62.5%) and resistant in 3 (37.5%). Overall, 13 patients died (35.1%); related mortality was 21.6% (8 patients). We conclude that HIV infection has become the most common underlying condition for invasive nocardiosis in our institution, followed by chronic lung disease. Previous use of corticosteroids was the main risk factor and was present in more than half the patients. New species of Nocardia have been identified, and administration of cotrimoxazole prophylaxis should no longer be considered highly reliable protection against nocardiosis. Larger studies of nocardiosis are required to better identify risk factors associated with mortality, and alternative and more effective methods of prevention must be developed.

Nocardiosis in adult-onset Still's disease and vasculitis syndrome

Four cases of nocardiosis in patients with adult-onset Still disease and vasculitis syndrome are presented. Three patients developed lung abscesses and 1 case developed a brain abscess. All were treated with high-dose corticosteroids, and 3 were given cyclosporine when they developed nocardiosis. All patients were successfully treated with antibiotics; cyclosporine was discontinued in 2 cases. These cases indicate that systemic nocardiosis can develop in patients with various rheumatologic diseases who are treated with corticosteroid and immunosuppressive drugs such as cyclosporine.

Pulmonary nocardiosis in a heart transplant patient: case report and review of the literature

Pulmonary infection with Nocardia is an uncommon but serious infection found in immunocompromised patients. We describe a rapidly progressive pulmonary nocardiosis in a heart transplant patient. We then review the common clinical features of Nocardia infection in transplant recipients, outlining the challenges in its diagnosis and management. We also review the differences between Pneumocystis jiroveci prophylaxis regimens with respect to concomitant prophylaxis of Nocardia and other opportunistic infections.

Disseminated nocardiosis due to unusual species: two case reports

Pulmonary nocardiosis is the major clinical manifestation of human nocardiosis and disseminated infection can be seen in immunocompromised patients. N. asteroides is the predominant pathogen associated with disseminated diseases. We report 2 cases of pulmonary nocardiosis admitted with disseminated infection, caused by rare species of Nocardia: Nocardia transvalensis and Nocardia cyriacigeorgica.

Pulmonary Complications in Heart Transplant Recipients

BACKGROUND

Heart transplantation is an important therapeutic option for patients with end-stage disease, but is associated with major pulmonary complications.

PATIENTS AND METHODS

We retrospectively reviewed the posttransplant follow-up of 34 orthotopic heart transplant recipients.

RESULTS

Two of the 34 patients died of cardiac failure in the early postoperative period. Among the surviving patients, 10 (31.3%) developed pulmonary complications, all within the first 6 months: hospital-acquired bacterial pneumonia in five, fungal pneumonia in three, posttransplant lymphoproliferative disease in one, and community-acquired pneumonia in one patient. None of the patients developed transplantation-related malignancy. The overall mortality was 35.3%. Pneumonia-related mortality rate of 14.7% was due to early-onset nosocomial pneumonias, which were caused by bacterial and opportunistic microorganisms. Extrapulmonary causes of mortality were cardiac failure, meningitis, septicemia, and acute rejection. Cytomegalovirus antigenemia in the first month was associated with a poor prognosis. The frequency of pulmonary complications was higher among older patients and those who developed moderate rejection in the first month (P=.014 and P=.036, respectively).

CONCLUSION

Pulmonary infections after heart transplantation occurred more frequently during the first 6 months posttransplantation, accounting for a significant portion of the posttransplantation mortality.

Nocardiosis following solid organ transplantation: a single-centre experience

Nocardiosis is a localized or disseminated bacterial infection caused by aerobic Actinomyces that commonly affects immunocompromised hosts. The aim of this study was to retrospectively review clinical course and outcome of nocardiosis in solid organ recipients at our centre. Five cases of nocardiosis were identified in a series of more than 4000 consecutive solid organ transplants performed at Innsbruck university hospital during a 25-year period. Of the five patients with nocardiosis, two had undergone multivisceral, one liver, one kidney and one lung transplantation. Three patients with Nocardia asteroides infection were treated successfully and recovered from their infectious disease, however, one lost his renal graft following withdrawal of immunosuppression. The lung recipient recovered from nocardiosis but died later on from Pseudomonas pneumonia. One multivisceral recipient died from Nocardia farcinica-disseminated infection. Nocardiosis is a rare, difficult-to-diagnose-and-treat complication following solid organ transplantation. Intestinal recipients might be at increased risk to develop this infection.

Nocardiosis in a teaching hospital in the Central Anatolia region of Turkey: treatment and outcome

Predisposing factors, antimicrobial susceptibility patterns, treatment and outcome were analysed for nine consecutive patients with nocardiosis. Predisposing factors were identified in six (67%) of the nine patients. Clinical syndromes of nocardial infection were pulmonary infection (three patients), cerebral infection (five patients) and disseminated infection (one patient). The predominant (60%) species was Nocardia farcinica rather than the Nocardia asteroides complex. Treatment was started empirically, modified according to the antimicrobial susceptibility pattern, and then continued for 6-12 months. Overall mortality was 33%, with death being caused by the Nocardia infection in two cases.

A case series and focused review of nocardiosis: clinical and microbiologic aspects

Nocardia species are ubiquitous soil organisms that often infect patients with underlying immune compromise, pulmonary disease, or a history of surgery or trauma. We report 5 cases of nocardiosis representing various aspects of this "great imitator": 1) pneumonia in the setting of underlying malignancy, 2) chronic pneumonia with drug-resistant organism, 3) bacteremia and empyema with chronic hematologic malignancy, 4) primary cutaneous disease, and 5) sternal wound infection. We present a summary of the English literature from 1966 to 2003 with a focus on the teaching points of each of our 5 cases as well as the background epidemiology and microbiology of the Nocardia genus. Isolation of the organism may be achieved with routine media but longer incubation times may be necessary, delaying diagnosis and appropriate therapy. Treatment with a sulfa-containing regimen is standard of care, but resistance testing is warranted given emerging drug resistance, high rates of discontinuation due to adverse reactions, and the potential for nephrotoxicity in transplant recipients on cyclosporine.