Nocardiosis in transplant recipients. Eur J Clin Microbiol Infect Dis. 2014;33:689-702. [PMID: 24272063 DOI: 10.1007/s10096-013-2015-5]

[Practices in infectious pathology in France in 2015. Results of the national survey]

Pathologists have been, are and will be always implicated in the diagnosis of infectious and tropical diseases. The resurgence of opportunistic infections due to the development of immunosuppressive drugs, the increase of migratory involvements draining tropical infections and the last epidemics spotlight the importance of pathologists in the field of infectious diseases. However, cancer is nowadays the first preoccupation of pathologists, which is constantly subject to evaluate diagnostic and prognostic markers and factors predictive to targeted therapy response or immunotherapy. As tumor pathology, infectious diseases require more sophisticated and rapidly changing complementary techniques, appraisals and perhaps a national network of diagnosis. The infectious pathology club committee carries out here a census of methods used in the diagnosis of infectious diseases in France in 2015 and particularly the different techniques used by laboratories to perform infectious diseases diagnosis. This will lay down the foundation of a future national organization of the infectious pathology in providing efficient services (diagnostic support, complementary tools) for the community of French pathologists in this specific domain of competence.

Syndrome of Inappropriate Antidiuretic Hormone Secretion Complicating Systemic Nocardiosis in a Renal Transplant Recipient: A Case Report

BACKGROUND

Infection by Nocardia species is an uncommon cause of severe clinical syndromes, particularly in immunocompromised patients, and solid-organ transplantation is the most common underlying condition. The syndrome of inappropriate antidiuretic hormone secretion (SIADH) has been described thus far in lung and stem cell transplants with systemic nocardiosis.

CASE REPORT

We report the first case of SIADH in a female elderly renal transplant recipient diagnosed with systemic nocardiosis 2 years after transplantation. The SIADH was managed appropriately, and her immunosuppressive regimen remained unchanged but was adjusted at a lower level. The systemic Nocardia infection was successfully treated with intravenous administration of trimethoprim-sulfamethoxazole and imipenem for 2 weeks followed by oral trimethoprim-sulfamethoxazole for a total of 12 months.

CONCLUSIONS

The SIADH syndrome is a recognizable complication of Nocardia infection in renal transplant recipients. Prompt identification along with proper management and prolonged antimicrobial treatment are essential to improve patients' outcome.

[Disseminated nocardiosis caused by Nocardia nova with brain abscesses and osteomyelitis in an immunocompetent patient]

INTRODUCTION

Nocardia is an opportunist bacteria involved in patients with cellular immunodepression or chronic lung disease. The most frequent portals of entry are the respiratory tract by inhalation or direct inoculation through a cutaneous effraction. Nocardiosis may be localised or disseminated.

CASE REPORT

We report a rare case of disseminated nocardiosis to Nocardia nova with pulmonary, cutaneous, cerebral attacks and femoral osteomyelitis. The diagnosis was confirmed by prolonged cultures of the bronchoalveolar fluid and the pus extracted from a cutaneous lesion. The outcome was favorable under adapted and prolonged antibiotherapy with imipenem and amikacine and then cotrimoxazole.

CONCLUSION

This observation is original because it involves a immunocompetent patient with an association of two exceptional locations for N. nova: brain abscesses and femoral osteomyelitis. Screening for cerebral involvement should be systematic, even in the lack of neurological signs. An adapted and prolonged antibiotherapy must be conducted.

Sepsis and Challenging Infections in the Immunosuppressed Patient in the Intensive Care Unit

In 2017, most intensive care units (ICUs) worldwide are admitting a growing population of immunosuppressed patients. The most common causes of pre-ICU immunosuppression are solid organ transplantation, hematopoietic stem cell transplantation, and infection due to human immunodeficiency virus. In this article, the authors review the most frequent infections that cause critical care illness in each of these 3 immunosuppressed patient populations.

[Respiratory infections caused by slow-growing bacteria: Nocardia, Actinomyces, Rhodococcus]

INTRODUCTION

Pneumonia caused by slow-growing bacteria is rare but sometimes severe.

STATE OF THE ART

These infections share many similarities such as several differential diagnoses, difficulties to identify the pathogen, the importance of involving the microbiologist in the diagnostic investigation and the need for prolonged antibiotic treatment. However, major differences distinguish them: Nocardia and Rhodococcus infect mainly immunocompromised patients while actinomycosis also concerns immunocompetent patients; the severity of nocardioses is related to their hematogenous spread while locoregional extension by contiguity makes the gravity of actinomycosis.

PROSPECTIVE

For these diseases, molecular diagnostic tools are essential, either to obtain a species identification and guide treatment in the case of nocardiosis or to confirm the diagnosis from a biological sample. Treatment of these infections is complex due to: (1) the limited data in the literature; (2) the need for prolonged treatment of several months; (3) the management of toxicities and drug interactions for the treatment of Nocardia and Rhodococcus.

CONCLUSION

Close cooperation between pneumonologists, infectious disease specialists and microbiologists is essential for the management of these patients.

Pulmonary and cutaneous infection caused by Nocardia farcinica in a patient with nephrotic syndrome: A case report

RATIONALE

Nocardia species is known as conditional pathogenic bacteria. Disseminated infection caused by Nocardia species is rare and occurs primarily in immunosuppressed patients. Signs and symptoms of this infection are frequently nonspecific making early diagnosis and treatment difficult.

PATIENT CONCERNS

We report a case of subcutaneous and pulmonary nocardiosis due to Nocardia farcinica (N farcinica) in a patient with nephrotic syndrome who is undergoing long-term corticosteroid therapy. In this patient, systemic and pulmonary symptoms (usually found in nocaria infection) such as fever, cough, and expectoration were absent.

DIAGNOSES

Early diagnosis was made by pus culture from subcutaneous abscesses and 16S rRNA gene sequencing, which confirm the diagnosis of N farcinica infection.

INTERVENTIONS

The patient was treated with combination therapy of cefatriaxone and trimethoprim-sulfamethoxazole (TMP-SMX) for 2 weeks, and the treatment with TMP-SMX continued to 6 months.

OUTCOMES

The abscesses were cured in 4 weeks and a lesion in the upper lobe of left lung resolved in 3 months.

LESSONS

This case indicates that disseminated infection due to N farcinica could occur in patients with nephrotic syndrome, even during the period of maintenance therapy with a low-dose corticosteroid and common signs and symptoms of infections could be absent.

Outcome and Treatment of Nocardiosis After Solid Organ Transplantation: New Insights From a European Study

BACKGROUND

Solid organ transplant (SOT) recipients are at risk of nocardiosis, a rare opportunistic bacterial infection, but prognosis and outcome of these patients are poorly defined. Our objectives were to identify factors associated with 1-year mortality after nocardiosis and describe the outcome of patients receiving short-course antibiotics (≤120 days).

METHODS

We analyzed data from a multicenter European case-control study that included 117 SOT recipients with nocardiosis diagnosed between 2000 and 2014. Factors associated with 1-year all-cause mortality were identified using multivariable conditional logistic regression.

RESULTS

One-year mortality was 10-fold higher in patients with nocardiosis (16.2%, 19/117) than in control transplant recipients (1.3%, 3/233, P < .001). A history of tumor (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.1-1.8), invasive fungal infection (OR, 1.3; 95% CI, 1.1-1.5), and donor age (OR, 1.0046; 95% CI, 1.0007-1.0083) were independently associated with 1-year mortality. Acute rejection in the year before nocardiosis was associated with improved survival (OR, 0.85; 95% CI, 0.73-0.98). Seventeen patients received short-course antibiotics (median duration 56 [24-120] days) with a 1-year success rate (cured and surviving) of 88% and a 5.9% risk of relapse (median follow-up 49 [6-136] months).

CONCLUSIONS

One-year mortality was 10-fold higher in SOT patients with nocardiosis than in those without. Four factors, largely reflecting general medical condition rather than severity and/or management of nocardiosis, were independently associated with 1-year mortality. Patients who received short-course antibiotic treatment had good outcomes, suggesting that this may be a strategy for further study.

Disseminated nocardiosis after unrelated bone marrow transplantation

Nocardiosis is a rare bacterial infection occurring mainly in patients with deficient cell-mediated immunity. Although disseminated nocardiosis after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a rare complication, it is associated with high mortality. Moreover, after allo-HSCT, nocardiosis may be mistaken for other bacterial or fungal infections because clinical and radiographic findings of pulmonary, cerebral, and cutaneous nocardiosis lesions are non-specific. Here, we report a case of disseminated nocardiosis (caused by Nocardia abscessus) with skin, pulmonary, liver, lymph node, and multiple brain abscesses in a patient after allo-HSCT. The patient initially responded clinically and radiographically to imipenem/cilastin and trimethoprim-sulfamethoxazole therapy. Clinicians should be aware of the possibility of nocardiosis in allo-HSCT recipients who are treated with multiple immunosuppressive agents to control chronic graft-versus-host disease. Accurate diagnosis and identification of disseminated nocardiosis is important to ensure administration of the correct antibiotic regimen.

Selected Topics in Aerobic Bacteriology

Aerobic Gram-positive and Gram-negative bacteria can be important pathogens in the immunocompromised host. These bacteria can be found in many environments, as part of the normal microbiota of the human host and animals, in soil and water, on plants, on fomites in the hospital, and on hospital equipment. This review provides information from relevant studies about what are the most common aerobic bacteria associated with patients who have cancer and/or are being treated for it, or who have other diseases which lead to immunodeficiencies, such as HIV, multiple myeloma, aplastic anemia, chronic diseases, and aging. A discussion of the appropriate laboratory tests needed for diagnosis of aerobic infections and information about antibiotics and susceptibility testing are also included.

[Nocardiosis: A retrospective case series of 19 patients]

INTRODUCTION

Nocardiosis are uncommon. The diagnosis may be difficult, with significant morbidity and mortality, often occurring on frail patients. Few data are available in France.

METHODS

A retrospective single center study was conducted from 2002 to 2014 and included all patients with at least one positive microbiological sample for Nocardia with a follow-up in our hospital.

RESULTS

Nineteen patients, including 15 men, were included with a mean age of 58 years (25-85). Seventeen had a risk factor (lung diseases [13], corticosteroids [12], solid neoplasia [2], HIV infection [2], diabetes mellitus [3], kidney transplant [2], lymphopenia [1]). Infections' locations were: pulmonary (12), brain (3), skin (2), lymph node (1) and corneal (1). The slow growth leads to a median of 35 days for a positive result (3-95). Nine species were identified. Fifteen patients (79%) received one or more lines of antibiotics including: cotrimoxazole (9), amoxicillin (7) cefotaxime/ceftriaxone (7) imipenem (3), or amikacin (3). The average duration of antibiotic therapy was 207 days. Four patients did not receive antibiotics due to a late result or a bacterial co-infection masking nocardiosis. Five patients died (26%) including 2 with cerebral nocardiosis. Six patients were cured, 4 suffered a relapse, 4 had an unknown evolution, and 1 was still treated.

CONCLUSION

Our study shows that nocardiosis is a disease difficult to treat. A better understanding of this type of infection is necessary.

Nocardiosis following hematopoietic stem cell transplantation

BACKGROUND

Nocardia species are ubiquitous environmental organisms that can cause a diverse spectrum of disease. Clinical manifestations range from localized skin and soft tissue infections to life-threatening pulmonary, central nervous system, and/or disseminated infections. Patients with hematologic malignancies undergoing hematopoietic stem cell transplantation (HSCT) are at risk for nocardiosis, and further data in regard to characteristics of disease in this population are warranted.

METHODS

We performed retrospective chart review of patients post allogeneic HSCT at Moffitt Cancer Center in Florida diagnosed with nocardiosis from 2003 to 2013.

RESULTS

In a decade, 15 cases of nocardiosis were identified. The majority of patients were men (11/15). The median age was 55 years (range 25-65). The most common type of transplant was matched-related donor (n = 8), followed by matched-unrelated donor (n = 3), mismatched-unrelated donor (n = 3), and double umbilical cord (n = 1). Ten received myeloablative conditioning (MAC) regimens. Twelve of 15 patients were on prednisone, 10 of which were on a total daily dose ≥20 mg. The median time from transplant to first positive culture was 10 months (range 1.5-93). Pulmonary nocardiosis was the most prevalent manifestation at 87%. Disseminated disease (2 or more sites of infection) was seen in 47%, whereas blood cultures were positive in 27% of the total cohort. The most common species was Nocardia nova (n = 4). At the time of diagnosis, 20% of the patients were receiving prophylaxis for Pneumocystis jirovecii pneumonia (PJP) with trimethoprim-sulfamethoxazole (TMP-SMX). Susceptibility data were available for 8 patients: all 8 samples were susceptible to TMP-SMX. Nocardiosis was treated with 2 or more active drugs in 93% of the patients. Overall mortality was 53%, with nocardiosis attributed as the cause in 62.5% (5/8). The absolute lymphocyte count at time of diagnoses was significantly lower in patients who ultimately experienced treatment failure.

CONCLUSION

Infection with Nocardia species in allogeneic HSCT recipients appears to be a late complication of transplantation and most commonly involves the lung. Two-thirds of the cohort received a MAC regimen and the majority of the patients were receiving steroids at the time of diagnosis. Most patients were not receiving TMP-SMX for PJP prophylaxis at the time of nocardiosis diagnosis, and TMP-SMX may therefore have a protective effect.

Infections

Even if heart transplantation is an undisputed source of medical progress, several complications still hamper the outcome of transplanted patients. Among them, infections are associated with significant morbidity, mortality, and economic burden.

Depending on clinical and radiological signs and based on the time interval after transplantation, a broad spectrum of microbial pathogens can be responsible for these infections. This microbiological diversity, associated with altered clinical signs due to immunosuppressive drugs, is a cause of delayed diagnosis and treatment.

The objective of this overview is to provide a structured procedure to explore fever and specific symptoms that can be suggestive of infection in heart-transplanted patients. Furthermore, main preventive and curative strategies will be described.

Pneumonia After Hematopoietic Stem Cell Transplantation

Pneumonia is the main cause of morbidity and mortality after hematopoietic stem cell transplantation. Two thirds of pneumonias observed after both autologous and allogeneic stem cell transplantations are of infectious origin, and coinfections are frequent. One third is due to noninfectious process, such as alveolar hemorrhage, alveolar proteinosis, or alloimmune pulmonary complications such as bronchiolitis obliterans or idiopathic interstitial pneumonitis. Most of these noninfectious complications may require treatment with corticosteroids which may be deleterious in infection. On the other hand, these complications either mimic or may be complicated with infections. Therefore, a precise diagnosis of pneumonia is of crucial importance to decide of the optimal treatment. CT scan is the best procedure for imaging of the lung. Although several indirect biomarkers, such as serum or plasma galactomannan or (1-3) β(beta)-G-glucan, can help in the etiological diagnosis, only direct invasive investigations provide the best chance to identify the cause(s) of pneumonia. Bronchoalveolar lavage (BAL) under fiberoptic bronchoscopy is the procedure of choice to identify the cause of pulmonary infection. It is safe and reproducible, and its diagnostic yield is around 50 % if the BAL fluid is processed at the laboratory according to a prespecified protocol established between the transplanter, the infectious diseases’ specialist, the pneumologist, and the laboratory, allowing the identification of the most likely hypotheses. Transbronchial biopsy does not provide significant additional information to BAL in most cases and more often complicates with bleeding and pneumothorax. In case of a noncontributory BAL, the decision to proceed to a second BAL, a transthoracic biopsy, or a surgical biopsy should be cautiously weighted in a multidisciplinary approach in regard to the benefits and risks of invasive procedures versus empirical treatment.

Nocardia Arthritis: 3 Cases and Literature Review

Nocardia are Gram-positive filamentous bacteria responsible for infections ranging from opportunistic life-threatening disseminated diseases to chronic skin and soft-tissue infections.Even if virtually all organs can be infected, articular involvement is rare. Therefore, we report 3 recent cases and performed a literature review of cases of Nocardia arthritis in order to describe clinical features, therapeutic challenges, and outcome of these patients.Among 34 patients (31 in the literature plus our 3 cases), 21 (62%) were due to hematogenous dissemination, 9 (26%) were due to direct bacterial inoculation through the skin, and in 4 cases, the mechanism of infection was unknown. Four out of these 34 cases occurred on prosthetic joints.Whereas hematogenous infections mostly occurred in immunocompromised hosts (17 of 21, 81%), direct inoculation was mostly seen in immunocompetent patients.Eighty-two percent of patients (28 out of 34) received trimethoprim-sulfamethoxazole-containing regimens and median antibiotic treatment duration was 24 weeks (range, 12-120) for hematogenous infections and 12 weeks (range, 6-24) for direct inoculations. Outcome was favorable in 27 cases despite unsystematic surgical management (17 cases) without sequelae in 70% of the cases.Nocardia arthritis is rare but its management is complex and should rely on a combined approach with rheumatologist, infectious diseases expert, and surgeon.

Clinical Analysis of Pulmonary Nocardiosis in Patients With Autoimmune Disease

Nocardiosis is an opportunistic infection that most commonly involves the lung; however, only a few case reports of autoimmune disease complicated by pulmonary nocardiosis exist in the literature. We conducted a retrospective analysis of 24 cases of both autoimmune disease and pulmonary nocardiosis at the Peking Union Medical College Hospital between 1990 and 2012. Fifty-two cases were hospitalized with nocardiosis, 24 of whom had at least 1 autoimmune disease before the diagnosis of pulmonary nocardiosis. The cohort patients consisted of 5 men and 19 women, with a mean age of 44.2 years. All were negative for human immunodeficiency virus. All but 1 patient had received immunosuppressants, including corticosteroids, cyclophosphamide, azathioprine, methotrexate, or hydroxychloroquine. Fever (87.5%), cough (83.3%), and sputum (79.2%) were the most common clinical manifestations. Ten cases were accompanied by subcutaneous nodules and/or cutaneous abscesses, and 4 had brain abscess. Half of them were lymphocytopenic. Thirteen of the 16 cases who underwent lymphocyte subtype analysis had decreased CD4+ T-cell counts. Nineteen cases had decreased serum albumin levels. Nocardia was isolated from sputum (13/24), bronchoalveolar lavage fluid (4/6), lung tissue (5/6), pleural effusions (3/5), skin or cutaneous pus (7/10), and brain tissue (1/1). The most common imaging findings were air-space opacities (83.3%), followed by nodules (62.5%), cavitations (45.8%), and masses (37.5%). Five were administered co-trimoxazole only, and the others were treated with 2 or more antibiotics. All 5 cases with skin abscesses and 2 of the 4 cases with brain abscesses were treated by surgical incision and drainage. None underwent thoracic surgery. Corticosteroid dosages were decreased in all cases, and cytotoxic agents were discontinued in some cases. Twenty-two cases recovered, and 2 died. Pulmonary nocardiosis associated with an underlying autoimmune disease showed a female predominance and presentation at younger age. Immunosuppressant therapy, lymphocytopenia, particularly low CD4+ T-lymphocyte counts, and low serum albumin levels may be disease susceptibility factors. Air-space opacities and nodules were the most common chest imaging features, and disseminated nocardiosis with lung and skin involvement was more common among them. Early diagnosis and anti-nocardial antibiotics with modulation of the basic immunosuppressive therapy were important for them.

Nocardia thailandica Pulmonary Nocardiosis in a Post-Solid Organ Transplant Patient

Nocardia thailandica is a rare pathogen related to Nocardia asteroides, Nocardia neocaledoniensis, and Nocardia caishijiensis that, since its original description in 2004, has only been reported to cause wound and ocular infections in humans. We report a case of pulmonary nocardiosis caused by Nocardia thailandica in a 66-year-old solid organ transplant patient from Connecticut, which was identified at the molecular taxonomic level by secA1 analysis, 16S rRNA gene sequencing, and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). To our knowledge, this is the first reported case of N. thailandica in the United States and the first report of pulmonary infection by this pathogen in the literature.

Human Nocardia Infections: A Review of Pulmonary Nocardiosis

Human nocardiosis may present as an acute or a chronic infection. Although a saprophyte Nocardia spp are responsible for superficial skin infections, pulmonary infections, and disseminated nocardiosis usually involving patients who are immunosuppressed and debilitated. Infections in immunocompetent individuals are usually chronic and present non-specific symptoms. Invasive and disseminated nocardiosis is common among patients with weakened cellular immune systems. Clinical diagnosis of pulmonary nocardiosis is difficult owing to the similarity of its presentation with other respiratory pathogens that include Actinomycetes members and Mycobacteriumtuberculosis. Laboratory diagnosis of human nocardiosis is plagued by the fact that a culture of Nocardia spp requires prolonged incubation periods for isolation which most laboratories fail to follow. The lack of clinical, laboratory, and epidemiological data on the incidence of nocardiosis in humans undermines its significance as a potential pathogen. This review attempts to reexamine the pathogenic potential of Nocardia in human infections

An Approach to a Pulmonary Infiltrate in Solid Organ Transplant Recipients

The onset of a pulmonary infiltrate in a solid organ transplant (SOT) recipient is both a challenging diagnostic and therapeutic challenge. We outline the potential aetiologies of a pulmonary infiltrate in a SOT recipient, with particular attention paid to fungal pathogens. A diagnostic and empirical therapy approach to a pulmonary infiltrate, especially invasive fungal disease (IFD) in SOT recipients, is provided.

First case of disseminated infection with Nocardia cerradoensis in a human

Here we report in a human, a renal transplant patient, the first disseminated infection with Nocardia cerradoensis, isolated after a brain biopsy. Species identification was based on 16S rRNA, gyrB, and hsp65 gene analyses. Antibiotic treatment was successful by combining carbapenems and aminoglycosides and then switching to oral trimethoprim-sulfamethoxazole.