Treatment of pulmonary nocardiosis in heart-transplant patients: importance of susceptibility studies

How do I manage nocardiosis?

BACKGROUND

Nocardiosis is a rare infection that is often difficult to treat and may be life-threatening. There is no consensus on its management.

OBJECTIVES

Our aim was to provide the current evidence for the diagnosis and management of individuals with nocardiosis, and to propose a management approach for this uncommon infection.

SOURCES

We systematically searched the medical literature on nocardiosis for studies published between 2010 and 2020 and describing ten or more individuals.

CONTENT

Nocardiosis, a primarily opportunistic infection which may occur in immunocompetent persons, most commonly involves the lungs and frequently disseminates to other sites including the central nervous system. The reference standard for Nocardia species identification is molecular biology, and the preferred method for antibiotic susceptibility testing (AST) is broth microdilution. Monotherapy seems appropriate for patients with primary skin nocardiosis or non-severe pulmonary disease; we reserve a multidrug regimen for more severe infections. Species identification and AST results are often missing at initiation of antibiotics. Trimethoprim-sulfamethoxazole is the preferred agent for initial therapy, because Nocardia is very often susceptible to this agent, and because it has been the keystone of nocardiosis treatment for years. Linezolid, to which Nocardia is almost always susceptible, may be an alternative. When combination therapy is required, the repertoire of companion drugs includes third-generation cephalosporins, amikacin and imipenem. Therapeutic modifications should take into account clinical response to initial therapy and AST results. Treatment duration of 6 months is appropriate for most situations, but longer durations are preferred for disseminated nocardiosis and shorter durations are reasonable in low-risk situations. Secondary prophylaxis may be considered in selected individuals with permanent immunosuppression.

IMPLICATIONS

We hereby provide the clinician with an easy-to-use algorithm for the management of individuals with nocardiosis. We also illuminate gaps in evidence and suggest future research directions.

Nocardiosis in Kidney Disease Patients under Immunosuppressive Therapy: Case Report and Literature Review

The increased use of novel and powerful immunosuppressive drugs in kidney diseases may concomitantly expose the patients to higher risk of opportunistic infections, some of which still remain underdiagnosed thus mishandled. As such, we recently had a less prepared encounter of pulmonary nocardial infection in an ANCA-associated renal vasculitis patient under steroid therapy. Despite the use of broad-spectrum antimicrobials including micafungin, the infection was still unbridled and eventually culminated in lethal brain abscess. We thus chose to renew the knowledge of the clinical features, imaging manifestations, differential diagnosis, specific laboratory tests and unique treatment about this rare infection in kidney diseases patients under immunosuppressive therapy. In addition, CT images of easily confused pulmonary lesions superimposed on kidney diseases were also retrieved from our depository. Moreover, impaired renal function as a risk factor for infection and pharmacological options for the treatment were also focused. By sharing our hard-learnt experience and reviewing the literatures, our report may contribute to the awareness among the clinicians in general and nephrologists in particular of this rare disease in susceptible patients and facilitate a swift thus life-saving treatment.

Unusual presentation of disseminated Nocardia abscessus infection in a patient with AIDS

A 40-year-old man with AIDS presented with symptoms of a chronic cough, subacute headache, generalised weakness with falls, urinary and faecal incontinence, and acute onset subcutaneous nodules. A chest CT scan showed multiple cavitary and nodular pulmonary infiltrates. MRI of his brain and spinal cord revealed innumerable ring-enhancing lesions. Pathological examination of the purulent material obtained from his subcutaneous lesions, as well as transbronchial tissue specimens obtained by biopsy, revealed beaded and branching Gram-positive rods, subsequently identified by 16S RNA sequencing to be Nocardia abscessus species. We observed an excellent therapeutic response to a combination antimicrobial therapy with resolution of the subcutaneous, pulmonary and central nervous system (CNS) lesions. Infections caused by N. abscessus are rare and typically occur in immunocompromised patients. In this article, we will review the presentation, diagnosis and treatment of N. abscessus infection.

Clinical spectrum and outcome of Nocardia infection: experience of 15-year period from a single tertiary medical center

INTRODUCTION

Nocardiosis, although very rare, is considered as an important opportunistic infection; however, recent literature is limited. This study describes all cases of nocardial infection treated in the authors' hospital to provide more information about clinical manifestations, species isolated, treatment and outcome of patients with nocardiosis.

METHODS

A retrospective review of the clinical features and outcome of nocardial infections was conducted during a 15-year period (1996-2010) at Rambam Health Care Campus.

RESULTS

The study included 53 patients with nocardial infection, 43 of them had underlying immunodeficiency. The most common clinical form was pulmonary nocardiosis with and without dissemination (60%), followed by skin and soft tissue infection (21%), bacteremia (11%) and pertonitis (5%). Resistance to trimethoprim/sulfamethoxazile was detected in 15% of isolates; to imipenem in 5% and to ciprofloxacin in 65%. Overall mortality was 25% (13/53), mainly observed in patients with pulmonary involvement (37.5%).

CONCLUSIONS

Nocardiosis is a rare infection and mainly affects immunocompromised patients. Higher index of suspicion is needed for earlier diagnosis and treatment to improve prognosis.

Efficacy of ciprofloxacin and moxifloxacin against Nocardia brasiliensis in vitro and in an experimental model of actinomycetoma in BALB/c mice

The efficacy of ciprofloxacin and moxifloxacin against Nocardia brasiliensis was evaluated by applying 25 mg of each drug/kg subcutaneously every 8 h in BALB/c mice infected with N. brasiliensis. A statistically significant difference was observed only with moxifloxacin. A moxifloxacin-trimethoprim-sulfamethoxazole combination was as active as when each compound was used alone.

Successful management of invasive pulmonary nocardiosis and aspergillosis in a patient with T-cell lymphoma: a case report

In patients with malignant hematological disorders receiving immunosuppressive therapy, invasive pulmonary infections are serious complications that are associated with high morbidity and mortality. In immunocompromised hosts with impaired cellular immunity, two or more organisms may coexist leading to a wide range of clinical and radiological manifestations.

Reported here is an old man who was diagnosed to have angioimmunoblastic T-cell lymphoma at King Faisal Specialist Hospital and Research Centre in Riyadh in December 2004. The lymphoma was treated with various immunosuppressive agents including alemtuzumab. In October 2006, the patient was admitted with severe bronchopneumonia caused by Nocardia asteroides and Aspergillus niger that was complicated by septic shock. The invasive pulmonary infections were successfully treated with trimethoprim-sulphamethoxazole, amikacin and liposomal amphotericin-B (amBisome).

In vivo therapeutic effect of gatifloxacin on BALB/c mice infected with Nocardia brasiliensis

In the present work, we evaluated the effect of gatifloxacin on the evolution of experimental murine infection with Nocardia brasiliensis using linezolid as a control. Gatifloxacin was injected subcutaneously at 100 mg/kg body weight every 8 h for 4 weeks. This compound was equally as efficient as linezolid in reducing the production of lesions.

Successful treatment of Nocardia nova bacteremia and multilobar pneumonia with clarithromycin in a heart transplant patient

Nocardia is an opportunistic pathogen in solid organ transplantation for which long-term sulfonamide therapy is considered the treatment of choice. We report a patient 7 months status post-orthotopic heart transplantation with Nocardia nova bacteremia and pneumonia. Initial treatment consisted of intravenous trimethoprim-sulfamethoxazole, which cleared blood cultures, but the patient subsequently went into renal failure and required alternative therapy. This report describes the first case of N nova bacteremia after orthotopic heart transplantation successfully treated with clarithromycin. All therapy should be guided by antibiotic sensitivity, and combination therapy should be considered in acutely ill patients and cases where in vitro synergy has been documented. This case suggests that clarithromycin can be an alternative treatment in cases of sulfonamide resistance, intolerance, or allergy.

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.

Secular trends of nocardia infection over 15 years in a tertiary care hospital

AIMS

To assess the incidence of nocardia infection over 15 years in a tertiary care hospital.

METHODS

Over a 15 year period, Nocardia spp were isolated from 20 patients hospitalised at the Geneva University Hospitals, Switzerland.

RESULTS

Sixteen patients had one or more underlying conditions. The median time between symptom onset and diagnosis was 30 days. The most common initial unconfirmed diagnosis was pulmonary tuberculosis (four). The lung was involved in 16 cases, followed by the central nervous system (two) and skin (two); one patient had disseminated infection. The most common species identified was N asteroides. In vitro susceptibility testing was performed on 14 of 20 strains. All strains were susceptible to imipenem and amikacin. Initial treatment with trimethoprim/sulfamethoxazole (TMP/SMX) was started in 14 patients, although five patients had to be switched to another treatment because of side effects or lack of efficacy. A cure was observed in 15 patients, death in three, and relapse or complications in two.

CONCLUSIONS

Nocardiosis can become a severe infection and mainly affects profoundly immunocompromised patients. Differential diagnosis often delays the time to diagnosis, which worsens the outcome. New diagnostic tools, such as the polymerase chain reaction, could provide more rapid and reliable results. TMT/SMX was the most commonly prescribed treatment, but needed to be changed for another treatment because of side effects or lack of efficacy in a considerable proportion of patients. Imipenem should be used as an alternative treatment for severely ill patients, and the sulfa combination for less severe infections.

Pulmonary nocardiosis in heart transplant recipients: treatment and outcome

BACKGROUND

Nocardial infections typically affect patients receiving immunosuppressants, occurring early after surgery in 3% to 40% of heart transplant (HTx) recipients. The emergence of antibiotic resistance and occurrence of disease recurrences in AIDS population has engendered controversy about the treatment for immunodepressed HTx patients.

METHODS

We present a retrospective study of the diagnosis, treatment and outcome of 560 HTx recipients between 1984 and 2002.

RESULTS

Among the five cases of Nocardia infection (0.9%), three cases developed late after HTx (between 3.1 and 11 years follow-up). All patients had pulmonary disease and one in addition had subcutaneous nodules. Microbiological diagnosis required open lung biopsy in one case. All patients were treated primarily with trimethoprim-sulphamethoxazole, but evidence of resistance to sulfonamides led us to change the antimicrobial combination in two cases. Four patients who received one year of antibiogram-guided therapy showed complete healing without recidivism. Three patients died, all due to non-related causes, at follow-ups between 1 and 5 years. In one case a cutaneous recurrence of disease was attributed to noncompliance.

CONCLUSIONS

Nocardiosis in current HTx is less common than previously reported. Its incidence seems to be delayed in time with modern immunosuppressants. Given the high incidence of sulfamide resistance, treatment must be guided by antibiotic sensitivity. We believe that maintenance therapy for a whole year is the appropriate option in order to avoid recidivism in this population.