Nocardia asteroides cerebral abscess in immunocompetent hosts: report of three cases and review of surgical recommendations

Cerebral nocardiosis in a patient treated with pembrolizumab: a first case report

Background

Checkpoints inhibitors (CPIs) are increasingly used for the treatment of several malignancies. The most common side effects are Immune Related Adverse Events, while infectious complications are rare, especially cerebral nocardiosis.

Case presentation

Here, we report the first clinical case of a cerebral nocardiosis revealed after seizure in a patient treated by pembrolizumab for a metastatic lung cancer, in the absence of any additional immunosuppressive therapy or risk factors for cerebral nocardiosis. The extended evaluation including a brain CT-scan did not reveal any lesion before pembrolizumab. Nevertheless, the 3-month delay between the start of Pembrolizumab and the diagnosis of cerebral nocardiosis suggests that the infection occurred prior to the CPI. Unfortunately, the patient died during treatment for cerebral nocardiosis, while the lung cancer tumor mass had decreased by 80% after the sixth cycle of pembrolizumab.

Conclusions

This case report emphasizes that clinicians should consider diagnoses other than metastasis in a patient with a brain mass and metastatic cancer treated with CPI, such as opportunistic infections or IRAE.

Nocardia Brain Abscess Mimicking Metastases in an Immunocompromised Patient

The differential for ring-enhancing lesions of the brain is extensive, with patient characteristics, particularly immunologic status, crucial to the clinical plan. In immunocompromised patients with a single ring-enhancing lesion, aspergillosis, toxoplasmosis, and nocardial infections are considered. In the case of multiple ring-enhancing lesions, metastases often supersede opportunistic infections on the differential. We present an unusual case of multiple nocardial brain abscesses mimicking metastases in an immunocompromised patient with a history of narcolepsy. 

Cerebral nocardiosis with osteomyelitis of skull vault complicating a primary neck lesion in an immunocompetent patient: a case report

Nocardia infection is an uncommon and rare condition in immunocompetent patient. A case of cutaneous nocardiosis complicated with osteomyelitis of the vault scalp in a 64-year-old man, with no remarkable past medical history, is reported. Treatment with trimethoprime-sulfamethoxazole than doxycycline for 12 months led to complete resolution and no evidence of recurrence was noted. Nocardia infection should be considered even in immunocomptent patients and doxycycline is a good alternative for treatment.

Molecular identification and antibiotic resistance pattern of actinomycetes isolates among immunocompromised patients in Iran, emerging of new infections

Recent advancements in DNA-based approaches have led to the identification of uncommon and rare bacterial pathogens. In this study, by utilizing a DNA-based approach, a total of 1043 clinical specimens were processed for the identification of actinobacteria targeting the 16S rRNA and gyrB genes. Drug susceptibility testing was also conducted using micro-broth dilution and PCR. Two isolates of Nocardia flavorosea and Rhodococcus erythropolis were reported for the first time in Iran. Also, Nocardiopsis dassonvillei, Streptomyces olivaceus, and Streptomyces griseus were reported for the first time in Asia. Infections caused by Nocardia caishijiensis and Prauserella muralis have also been reported in this study. The first Asian case of pulmonary infection caused by Nocardia ignorata and the first global case of brain abscess caused by Nocardia ninae and Nocardia neocaledoniensis have been reported in this study. Overall 30 isolates belonging to 6 genera (Nocardia, Streptomyces, Rodoccoccus, Nocardiopsis, Rothia, and Prauserella) were detected in 30 patients. All 30 isolates were susceptible to amikacin and linezolid. Three isolates including Nocardia otitidiscaviarum (n = 2) and Nocardia flavorosea (n = 1) were resistant to trimethoprim-sulfamethoxazole which were the first trimethoprim-sulfamethoxazole resistant clinical actinomycetes in Iran. Isolation of rare species of actinomycetes particularly Nocardia spp. requires urgent action before they spread clinically particularly among immunocompromised patients.

Multiple Brain Abscesses Due to Nocardia otitidiscaviarum: Case Report and Treatment Implications

Nocardia infections typically present in immunocompromised hosts. Brain abscesses caused by species such as Nocardia asteroides, farcinica, and abscessus are well-documented in the literature. We present a rare case of an immunocompetent patient with multiple brain abscesses due to Nocardia otitidiscaviarum requiring a decompressive fronto-temporoparietal craniectomy due to symptomatic intracranial hypertension. The patient was treated with intrathecal amikacin in addition to standard antibiotics with the resolution of the disease and good neurologic outcome. This is one of few case reports overall involving this species within the brain, and the second to report favorable outcomes. This case describes implications for treatment and adds to sparse literature regarding this particular pathogen.

Isolated Nocardiosis, an Unrecognized Primary Immunodeficiency?

Nocardiosis is an infectious disease caused by the gram-positive bacterium Nocardia spp. Although it is commonly accepted that exposure to Nocardia is almost universal, only a small fraction of exposed individuals develop the disease, while the vast majority remain healthy. Nocardiosis has been described as an "opportunistic" disease of immunocompromised patients, suggesting that exposure to the pathogen is necessary, but a host predisposition is also required. Interestingly, increasing numbers of nocardiosis cases in individuals without any detected risk factors, i.e., without overt immunodeficiency, are being reported. Furthermore, a growing body of evidence have shown that selective susceptibility to a specific pathogen can be caused by a primary immunodeficiency (PID). This raises the question of whether an undiagnosed PID may cause nocardiosis affecting otherwise healthy individuals. This review summarizes the specific clinical and microbiological characteristics of patients with isolated nocardiosis published during the past 30 years. Furthermore, it gives an overview of the known human immune mechanisms to fend off Nocardia spp. obtained from the study of PIDs and patients under immunomodulatory therapies.

Epitope-Based Vaccine Designing of Nocardia asteroides Targeting the Virulence Factor Mce-Family Protein by Immunoinformatics Approach

Nocardia asteroides is the main causative agent responsible for nocardiosis disease in immunocompromised patient viz. Acquired Immunodeficiency Syndrome (AIDS), malignancy, diabetic, organ recipient and genetic disorders. The virulence factor and outer membrane protein pertains immense contribution towards the designing of epitopic vaccine and limiting the robust outbreak of diseases. While epitopic based vaccine element carrying B and T cell epitope along with adjuvant is highly immunoprophylactic in nature. Present research equips immunoinformatics to figure out the suitable epitopes for effective vaccine designing. The selected epitopes VLGSSVQTA, VNIELKPEF and VVPSNLFAV amino acids sequence are identified by HLA-DRB alleles of both MHC class (MHC-I and II) molecules. Simultaneously, these also accessible to B-cell, confirmed through the ABCPred server. Antigenic property expression is validated by the Vaxijen antigenic prediction web portal. Molecular docking between the epitopes and T cell receptor delta chain authenticate the accurate interaction between epitope and receptor with significantly low binding energy. Easy access of epitopes to immune system also be concluded as transmembrane nature of the protein verified by using of TMHMM server. Appropriate structural identity of the virulence factor Mce-family protein generated through Phyre2 server and subsequently validated by ProSA and PROCHECK program suite. The structural configuration of theses epitopes also shaped using DISTILL web server. Both the structure of epitopes and protein will contribute a significant step in designing of epitopic vaccine against N. asteroides. Therefore, such immunoinformatics based computational drive definitely provides a conspicuous impel towards the development of epitopic vaccine as a promising remedy of nocardiosis.

First reported case of disseminated Nocardia kroppenstedtii sp nov. infection presenting with brain abscess and endocarditis in an immunocompromised patient with mantle cell lymphoma: challenges in diagnosis and treatment

A 72-year-old man with a history of blastoid variant stage IV relapsed refractory mantle cell lymphoma presented with new central nervous system (CNS) symptoms. Brain imaging was positive for rim-enhancing lesions along with a mitral valve mass on the echocardiogram. It was a challenge to establish the exact aetiology of these lesions in this patient. He was empirically treated with chemotherapy on the presumption that the brain lesions were secondary to progressive malignancy. However, brain biopsy was negative for malignancy and blood cultures were found positive for Nocardia kroppenstedtii sp nov. He subsequently improved with antibiotic therapy. Disseminated Nocardia can present with multiorgan involvement. Clinical and microbiological diagnosis can be challenging. Antimicrobial treatment-related side effects require close monitoring, and dosage changes or therapy adjustments may be necessary.

LInezolid for the Treatment of Nocardia spp. Infections

Objective:

To review the available evidence regarding the use of linezolid for the treatment of Nocardia spp. infections.

Data Sources:

Data were identified through a search of MEDLINE (1966-May 2007), American Search Premier (1975-May 2007), International Pharmaceutical Abstracts (1960-2007), Science Citation Index Expanded (1996-2007), and Cochrane Databases (publications archived until May 2007) using the terms linezolid and Nocardia.

Study Selection and Data Extraction:

Prospective and retrospective studies, case reports, case series, and in vitro studies were eligible for inclusion if they used linezolid for nocardiosis regardless of site of infection and outcome.

Data Synthesis:

We identified 11 published cases of linezolid use for Nocardia spp. infections. The predominant species isolated were N. asteroides (n=4; 36%) and N. farcinica (n= 3; 27%). Nocardiosis with central nervous system involvement (n= 7; 64%) or disseminated disease (n= 4; 36%) were most common. The main reason for discontinuation of previous antimicrobials was most often related to adverse effects (n= 5; 45%), followed by clinical failure (n = 3; 27%). Linezolid was associated with cure or improvement in all cases (n =11; 100%). However, the majority of patients developed serious complications that may have led to premature discontinuation of therapy with linezolid, including myelosuppression (n = 5; 45%) or possible/confirmed peripheral neuropathy (n = 2; 18%).

Conclusions:

The limited published data suggest that linezolid appears to be an effective alternative to trimethoprim/sulfamethoxazole for the treatment of nocardiosis. Unfortunately, the high cost and potentially serious long-term toxicities of linezolid appear to limit its use and relegate it to salvage therapy alone or in combination with other antimicrobials.

Nocardia abscessus-related intracranial aneurysm of the internal carotid artery with associated brain abscess: A case report and review of the literature

Nocardia infections primarily begin in the lungs and spread hematogenously to other sites in the body. Thus, a Nocardia brain abscess is not a completely uncommon occurrence. However, a Nocardia brain abscess complicated by a middle cerebral artery and infectious intracranial aneurysm is a very rare clinical entity. We present a case of an infectious intracranial aneurysm with an associated Nocardia brain abscess that required surgical intervention and resection. The patient was an immunocompetent 60-year-old male who presented with a chief complaint of headache and was found to have an infected intracranial aneurysm and cerebral abscess. He underwent drainage of the abscess with subsequent resection of the infected aneurysm. Cultures from both the blood vessel and brain tissue grew Nocardia abscessus. He was successfully treated with 6 weeks of ceftriaxone and high-dose trimethoprim-sulfamethoxazole. Infectious intracranial aneurysms of the brain caused by Nocardia are rare occurrences, and only a single previous case has been described in the literature. The outcomes of this condition can be catastrophic if it is not treated with a combination of surgery and intravenous antibiotics. The guidelines for the management of this infection are not well defined at this time.

Subtentorial cerebral nocardiosis in immunocompetent patients: CT and MR imaging findings

PURPOSE

To describe the clinical presentation and computed tomography (CT) and magnetic resonance imaging (MRI) appearances of subtentorial nocardia cerebral abscesses developing in immunocompetent patients.

PATIENTS AND METHODS

The clinical findings and the results of CT and MRI examinations of three immunocompetent patients with nocardiosis located initially only in the subtentorial region were studied. Three patients underwent CT examination and two patients had MRI.

RESULTS

Clinically, two patients had cerebellar syndrome and the third had meningism with fever. The diagnosis of nocardiosis was bacteriologically confirmed by demonstrating the organism in lumbar puncture fluid in one patient and by an aspiration biopsy of the abscess in the other two. Two of the patients improved under targeted antibiotic therapy whereas the third patient died. The main imaging features of the lesions were a multiloculated appearance with peripheral enhancement after intravenous administration of iodinated contrast material on CT and a multicystic appearance on MRI, with a peripheral hypointense rim on T2-weighted images, a relatively minor mass effect and a multiloculated appearance on gadolinium-chelate enhanced T1-weighted images.

CONCLUSION

The clinical presentation of cerebral nocardiosis is relatively non-specific. A microcystic lesion surrounded by hypointensity on T2-weighted MR images with a multiloculated pattern after gadolinium chelate administration on T1-weighted MR images in association with a relatively minor mass effect should suggest this diagnosis even if the lesion is single and in the absence of immunosuppression.

Cerebral nocardiosis

Cerebral Nocardiosis is a rare, challenging, opportunistic infectious disease of the central nervous system occurring in both immunocompetent and immunocompromised hosts. It often results in intraparenchymal abscess formation, which represents only 2% of all cerebral abscesses. The diagnosis of cerebral Nocardiosis is seldom based on imaging. Bacteriological diagnosis is often reached only after surgical excision of the abscess. We report a rare case of brain abscess caused by Nocardia species in a 20-year-old immunocompromised lady. Total surgical excision of the abscess, prompt bacteriological diagnosis based on smear and culture of the pus and initiation of specific antimicrobial therapy (trimethoprim and sulfamethoxazole) resulted in good clinical outcome.

Clinical Pathway in the Treatment of Nocardial Brain Abscesses following Systemic Infections

Nocardial infections are commonly encountered in patients with immunocompromised states. Cerebral nocardiosis is an uncommon clinical entity, representing only 2% of all cerebral abscesses. It has a higher mortality rate, especially for multiple cerebral lesions in immunocompromised hosts following systemic infections. However, an optimal treatment policy to deal with these immunocompromised patients in Asia is still lacking. We retrospectively reviewed the subjects with nocardial brain abscesses from 2001 to 2011 at our medical center. All of them had multiple brain abscesses, underlying with immunocompromised state following systemic infections. All cases were under steroid control due to their comorbidities for more than six months. The comorbidities and misdiagnosis often lead to poor prognosis. The change in the environments of the microorganisms caused by immunosuppressive agents and multiple antibiotic uses may play an important role in this critical disorder. Aggressive craniotomy should be performed in time to avoid grievous neurological outcomes. Our conclusion is that early diagnosis and appropriate antibiotic uses should be implemented promptly, and aggressive craniotomy should be performed for nocardial brain abscesses in subjects with systemic infections under an immunocompromised status.

Nocardia brain abscess in an immunocompetent patient

Nocardia cerebral abscess is rare, constituting approximately 1-2% of all cerebral abscesses. Mortality for a cerebral abscess of Nocardia is three times higher than that of other bacterial cerebral abscesses, therefore, early diagnosis and therapy is important. Nocardia cerebral abscess is generally occur among immunocompromised patients, and critical infection in immunocompetent patients is extremely rare. We report on a case of a brain abscess by Nocardia farcinica in an immunocompetent patient who received treatment with surgery and antibiotics. This is the second case of a brain abscess caused by N. farcinica in an immunocompetent patient in Korea.

The prevalence and clinical characteristics of systemic lupus erythematosus with infectious brain lesions in China

OBJECTIVE

Infectious brain lesions (IBLs) are life-threatening in patients with systemic lupus erythematosus (SLE). The aim of this study was to determine the prevalence of IBL in SLE patients and the clinical characteristics of SLE patients with IBL.

METHODS

Medical charts of 15 consecutive SLE patients with IBL admitted to Peking Union Medical College Hospital (PUMCH) from January 1995 to October 2010 were reviewed systematically. A total of 150 cases were randomly selected as controls from 4115 SLE inpatients without IBL in PUMCH during the same period.

RESULTS

The prevalence of IBL in SLE patients was 0.4%. Significant differences were observed between SLE patients with and without IBL in the following manifestations (p < 0.05): arthritis/musculoskeletal involvement (66.7% vs. 32.0%), C-reactive protein (CRP) elevation (84.6% vs. 28.0%), anti-dsDNA antibody positivity (13.3% vs. 42.9%), and elevated SLE Disease Activity Index (SLEDAI) score (> 5) (13.3% vs. 71.3%). Fever was the most common manifestation (80%), followed by headache and focal neurological signs (73.3%). Twelve patients presented with infections in other sites, including pulmonary infection (66.7%) and meningitis (40.0%). Enhanced cranial magnetic resonance imaging (MRI) revealed point-enhancing or ring-enhancing lesions in all patients evaluated (12/12, 100%). Mycobacterium tuberculosis was the most common pathogen (10 cases, 66.7%). After administration of antibiotics targeting the pathogens, 11 patients (73.3%) recovered.

CONCLUSIONS

IBL is not common in SLE patients. In stable SLE patients with fever, focal neurological signs, and CRP elevation, IBL should be suspected. Enhanced cranial MRI and a thorough check-up should be performed in a timely manner. It is very important to identify the pathogens and initiate treatment as early as possible.

Nocardia farcinica brain abscesses in an HIV-positive patient

We present a case of Nocardia farcinica brain abscesses in an HIV-positive patient, initially misdiagnosed as cerebral toxoplasmosis. The correct diagnosis was eventually confirmed by brain biopsy. It is debatable as to whether surgical intervention is necessary for diagnosis and treatment of Nocardia abscesses. This case highlights the importance of early neurosurgical input and biopsy to aid correct and timely diagnosis.

Disseminated Nocardia farcinica: literature review and fatal outcome in an immunocompetent patient

BACKGROUND

Nocardia farcinica is a gram-positive, partially acid-fast, methenamine silver-positive aerobic actinomycete. Nocardia spp. are opportunistic pathogens, and N. farcinica is the least common species of clinical importance.

METHODS

Review of the recent literature and description of a immunocompetent patient with no known risk factors who contracted fatal N. farcinica sepsis.

RESULTS

Positive pre-mortem and post-mortem cultures from the lung and synovium correlated with acute bronchopneumonia and synovitis at autopsy. Colonies of filamentous bacteria, which were not apparent in conventional hematoxylin and eosin-stained sections, were observed with gram and methenamine silver stains, but acid-fast stains were negative. A literature review revealed that disseminated N. farcinica often is associated with an underlying malignant tumor or autoimmune disease (88% of patients). Chemotherapy or corticosteroid treatments are additional risk factors.

CONCLUSIONS

Trimethoprim-sulfamethoxazole typically is the first-line therapy for N. farcinica; treatment with amikacin and imipenem-cilastatin is used less often (7% of patients). Despite aggressive therapy, we observed that the death rate (39%) associated with N. farcinica in recent publications was eight percentage points higher than reported in a review from 2000.

Concurrent nocardia related brain abscess and semi-invasive pulmonary aspergillosis in an immunocompetent patient

We describe here the first case of a concurrent brain abscess caused by Norcardia spp. and semi-invasive pulmonary aspergillosis in an immunocompetent patient. After one year of appropriate antimicrobial therapy and surgical drainage of the brain abscess, the nocardia brain abscess and pulmonary aspergillosis have resolved.

Cerebellar nocardiosis and myopathy from long-term corticosteroids for idiopathic thrombocytopenia

Infection of the central nervous system with Nocardia sp. usually manifests as supratentorial abscesses. Supratentorial and cerebellar abscesses from infection with Nocardia sp. following immunosuppression with long-term corticosteroids for idiopathic thrombocytopenia (ITP) have not been reported. An 83 years-old, human immunodeficiency virus (HIV)-negative, polymorbid male with ITP for which he required corticosteroids since age 53 years developed tiredness, dyspnoea, hemoptysis, abdominal pain, and progressive gait disturbance. Imaging studies of the lung revealed an enhancing tumour in the right upper lobe with central and peripheral necrosis, multiple irregularly contoured hyperdensities over both lungs, and right-sided pleural effusions. Sputum culture grew Nocardia sp. Neurological diagnostic work-up revealed dysarthria, dysphagia, ptosis, hypoacusis, tremor, dysdiadochokinesia, proximal weakness of the lower limbs, diffuse wasting, and stocking-type sensory disturbances. The neurological deficits were attributed to an abscess in the upper cerebellar vermis, myopathy from corticosteroids, and polyneuropathy. Meropenem for 37 days and trimethoprime-sulfamethoxazole for 3 months resulted in a reduction of the pulmonary, but not the cerebral lesions. Therefore, sultamicillin was begun, but without success. Long-term therapy with corticosteroids for ITP may induce not only steroid myopathy but also immune-incompetence with the development of pulmonary and cerebral nocardiosis. Cerebral nocardiosis may not sufficiently respond to long-term antibiotic therapy why switching to alternative antibiotics or surgery may be necessary.

Nocardia brain abscess: severe CNS infection that needs aggressive management; case report

Nocardia brain abscess is a rare central nervous system (CNS) infection that carries a high mortality rate reaching 34% which is considered the highest amongst brain abscesses caused by microorganisms. All available literature is in the form of retrospective studies and small case series. In this case report the authors present a patient whose course of disease was stormy and required multiple neurosurgical procedures. The clinical outcome, long-term follow up and a review of the literature is discussed.

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.

A cluster of nocardial brain abscesses

BACKGROUND

Nocardia species are aerobic Gram-positive bacteria that are ubiquitous in the environment. Infection usually occurs through inhalation or direct cutaneous inoculation of the organism. It has been reported that infection is more common in warm, dry climates. Cerebral nocardiosis is an uncommon clinical entity, representing only 2% of all cerebral abscesses. It is an illness associated with significant morbidity and mortality.

CASE DESCRIPTIONS

We report 4 cases of nocardial brain abscesses presenting to TCH, Australia, within a 1-year period. All 4 cases occurred in men without any significant underlying immunocompromise. In 3 of the cases, the diagnosis was only established after craniotomy. All cases were given prolonged antimicrobial therapy. After more than 8 months of follow-up, there have been no deaths or treatment failures. There has been only one other case of nocardial brain abscess at TCH over the past 15 years. We review the current literature on cerebral nocardiosis.

CONCLUSION

Nocardial brain abscesses are uncommonly encountered at our institution. This cluster of 4 cases over a 1-year period has therefore led us to postulate that the severe drought may be aiding in the transmission of the bacteria. The cases also emphasize the propensity of nocardial infections to mimic other conditions, particularly malignancy, which may lead to delays in appropriate surgical treatment and antimicrobial therapy. The diagnosis requires a high clinical index of suspicion, with early tissue and microbiological diagnosis. Prolonged antimicrobial therapy is required to prevent relapse of the infection.

Choroid plexitis in a case of systemic nocardiosis

Although rare, primary choroid plexitis can occur as an early presentation of a central nervous system (CNS) infection most commonly with cryptococcosis, tuberculosis, and nocardiosis. In the appropriate clinical setting, an enlarged, intensely enhancing choroid plexus should raise suspicion for choroid plexitis. It is important to recognize this entity early as aggressive diagnostic and therapeutic intervention may be necessary. We review the existing literature and present a case of infectious choroid plexitis in a patient with systemic nocardiosis; computed tomography and magnetic resonance imaging demonstrated the characteristic findings of choroid plexitis, which later developed into a parenchymal abscess.

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

Nocardiosis is a serious infection with high mortality. We report a case of subcutaneous and neural lesions due to Nocardia farcinica infection after living-donor liver transplantation. The neural lesion was cured with antibiotics without drainage.

N. paucivorans infection presenting as a brain abscess

We report an intracerebral abscess caused by a recently identified nocardial species, in an immunocompetent individual without extraneural involvement.

A 63-year-old non-smoking Caucasian male with an unremarkable history of hypertension, presented with a 2-week history of personality changes including apathy, some difficulty walking, a tendency to veer to the left and a possible seizure. Preliminary assessment, including laboratory investigations were unremarkable. Computed tomography (CT) of his brain revealed a right frontal lobe multi-loculated, ring-enhancing lesion with vasogenic edema and associated mass effect (Figure 1). He was then referred to our institution.

Actinomycoses and Nocardia pulmonary infections

PURPOSE OF REVIEW

Actinomycosis and nocardiosis are uncommon pulmonary infections with distinct morphologic features. Both infections most commonly present as chronic, debilitating illnesses with radiographic manifestations simulating lung cancer or tuberculosis. Immunocompromised hosts, however, may develop fulminant disease resembling acute bacterial pneumonia. The purpose of this review is primarily to review the clinical features, diagnosis, and management of actinomycosis and nocardiosis.

RECENT FINDINGS

Treatment of actinomycosis is usually simple, requiring long-term, high-dose intravenous penicillin. Short-course chemotherapy, however, has recently been reported to be successful. Pulmonary nocardiosis is an important cause of opportunistic infection in immunosuppressed patients, and the incidence of this infection is increasing. The sulfonamides are still first-line agents in the management of nocardiosis, but resistance is most common among N. farcinica and N. otitidiscaviarum isolates. Carbapenems should be used as an alternative treatment for severely ill patients. Broth microdilution, E-test (AB Biodisk, Solna, Sweden) and BACTEC (Becton Dickinson, Sparks, Maryland, USA) radiometric method may be more useful in the routine clinical laboratory for antimicrobial testing of aerobic actinomycetes.

SUMMARY

The practical distinction between the two diseases is in the matter of therapy. Diagnosis depends on a high degree of suspicion so as to alert the microbiology and pathology laboratories to employ special methods to identify the organisms. Early recognition and prompt treatment usually results in complete cure.

Absceso recidivante por Nocardia asteroides en una paciente portadora de poliglobulia primaria

La nocardiosis del sistema nervioso central (SNC) es una enfermedad poco común, cuya frecuencia ha aumentado con el crecimiento de los tratamientos inmunosupresores. El hombre se infecta por inhalación, inoculación traumática cutánea directa y tras una infección periodontal ingiriendo alimentos contaminados. La localización pulmonar es la más frecuente, siendo la fuente inicial de diseminación hemática, con predominio en piel, tejido celular subcutáneo y SNC. Es conocida la predilección de Nocardia por el SNC. Estos abscesos, asociados a altos índices de mortalidad, especialmente en pacientes inmunocomprometidos, siguen constituyendo un desafío diagnóstico y terapéutico, permaneciendo no aclarado su manejo terapéutico óptimo. A pesar de la controversia en cuanto al manejo quirúrgico de estas lesiones, el diagnóstico precoz, por aspiración esterotáxica, y la iniciación de una terapia antimicrobiana son esenciales para la buena evolución del paciente. Se presenta una paciente portadora de una poliglobulia primaria, con absceso cerebral recidivante por Nocardia asteroides de posible origen dentario.

Nocardial brain abscess: Review of clinical management

Nocardiosis has become a significant opportunistic infection over the last two decades as the number of immunocompromised individuals has grown worldwide. We present two patients with nocardial brain abscess. The first patient was a 39-year-old woman with systemic lupus erythematosus. A left temporoparietal abscess was detected and aspirated through a burr-hole. Nocardia farcinica infection was diagnosed. The patient had an accompanying pulmonary infection and was thus treated with imipenem and amikacine for 3 weeks. She received oral minocycline for 1 year. The second patient was a 43-year-old man who was being treated with corticosteroids for glomerulonephritis. He was diagnosed with a ring-enhancing multiloculated abscess in the left cerebellar hemisphere, with an additional two small supratentorial lesions and triventricular hydrocephalus. Gross total excision of the cerebellar abscess was performed via a left suboccipital craniectomy. Culture revealed Nocardia asteroides, and the patient was successfully treated with intravenous ceftriaxone, then oral trimethoprime-sulfamethoxazole for 1 year. The clinical course, radiological findings, and management of nocardial brain abscess are discussed in light of the relevant literature, and current clinical management is reviewed through examination of the cases presented here.

A rapidly enlarging nocardial brain abscess mimicking malignant glioma

Nocardial brain abscesses are uncommon and are not preceded by clear infectious symptoms in most cases. Delayed identification of the bacteria is responsible for a high mortality rate. A 58-year-old afebrile woman was admitted to our hospital because of progressive right hemiparesis and aphasia. Magnetic resonance imaging (MRI) showed a single ring-enhanced lesion in the left frontal lobe. It was extremely difficult to establish the diagnosis of brain abscess, because the laboratory data provided little evidence of bacterial infection, (201)TlCl-scintigraphy revealed definite accumulation of thallium in the lesion, and follow-up MRI demonstrated rapid enlargement of the lesion. Total resection was performed because of the possibility of a malignant brain tumor, but brain abscess was finally diagnosed with histological examination. A nocardial species was detected through microscopic examination of the pus obtained at surgery, and this precise diagnosis of nocardial brain abscess in the early stage enabled the administration of appropriate antibiotics and the patient's quick recovery. Nocardial brain abscesses are often misdiagnosed as malignant brain tumors, and a definitive diagnosis may not be possible without detecting bacteria from the lesion. Total excision of the abscess can produce good results when the abscess is large and located superficially, but incomplete aspiration and drainage of a lesion is associated with a high chance of relapse.

Nocardiosis in a tertiary care hospital on the island of Gran Canaria

Background: Nocardiosis is an uncommon but serious infection increasingly found in immunosuppressed persons. We describe 14 cases of nocardial infection seen at a tertiary hospital. Methods: All positive Nocardia cultures isolated from 1991 to 2002 were included. We analyzed predisposing factors, epidemiological and clinical features, laboratory and radiological findings, site(s) of infection, antimicrobial susceptibility pattern, treatment, and outcome. Factors related to mortality were analyzed. Results: Nineteen patients with a Nocardia isolate were identified and 14 were finally included. The most common predisposing factors included pulmonary diseases (71.4%), diabetes mellitus (35.7%), systemic diseases (28.6%) and immunosuppressive therapy (28.6%). The site of infection was pulmonary in 12 cases (85.71%), cutaneous or subcutaneous in one case (7.1%), and disseminated in another case (7.1%). The predominant clinical symptom was purulent expectoration (71.4%) while the predominant radiological pattern was a reticulonodular infiltrate (6/12, 50%). Relapse was observed in one case (7.7%) and death in three cases (23.1%). Diabetes mellitus was associated with the mortality rate (p=0.035). Treatment was highly individualized, but trimethoprim (TMP)-sulfamethoxazole (SMX) was the combination most often used. Conclusions: Nocardiosis should be part of the differential diagnosis for patients presenting with pulmonary symptoms, soft tissue infection, or brain abscess.

Nocardial brain abscess in a renal transplant recipient

Nocardial brain abscess is rare and accounts for about 1-2% of all cerebral abscesses. However, the early detection and treatment of it is very important because the mortality of it is three times higher than that of other bacterial brain abscesses. We report a case of nocardial brain abscess in a renal transplant recipient. Enhanced brain CT and MR scans showed multiple conglomerated ring-enhancing lesions with budding appearance and distinct surrounding edema.

Nocardia brain abscess misinterpreted as cerebral infarction

We present the case of a non-immunocompromised man with right-sided hemiparesis and aphasia thought to be caused by cerebral infarction, but which in the later clinical course evolved to be a nocardia brain abscess that needed surgical intervention. Misinterpretation of imaging combined with the absence of clinical signs of infection led to inadequate primary treatment

Nocardial cerebral abscess: report of three cases and review of the current neurosurgical management

Nocardia asteroides cerebral abscesses are rare but challenging intracranial lesions. Early diagnosis, institution of appropriate antimicrobial therapy, lack of underlying systemic disease and limited intracranial disease are recognized factors leading to good outcome. However, the optimal treatment approach has not been established and nocardial brain abscesses have been managed either conservatively, with steroetactic aspirations or with open craniotomy and enucleation. We present three cases of Nocardia asteroides cerebral abscesses cured only after neurosurgical enucleation, and discuss the current management alternatives and conclude that a more aggressive approach than that currently preferred for this entity may be more effective.

Surgical treatment of nocardial brain abscesses

OBJECTIVE

Nocardial brain abscesses are associated with significant morbidity and mortality rates. The optimal management remains unclear. We reviewed the surgical outcomes of patients treated with a relatively uniform policy at a single institution.

METHODS

Eleven patients were treated at the Royal Adelaide Hospital between 1970 and 2001. Their clinical presentations, surgical treatment, and outcomes were reviewed.

RESULTS

Clinical presentations most frequently involved focal neurological deficits (91%). Predisposing factors were identified for 63% of the patients. Nine patients were treated only with aspiration and long-term chemotherapy. Two patients underwent craniotomy and lesion excision. The majority of patients required either one or two procedures. There were no deaths in this series. Management complications were observed for three patients. Abscess aspiration was complicated by parenchymal hemorrhage and ventriculitis for one patient and temporary worsening of hemiparesis for two patients.

CONCLUSION

Our results suggest that aspiration alone (repeated as clinically indicated) is a safe, efficacious treatment for the majority of patients with nocardial brain abscesses.

Isolation of Nocardia paucivorans from the cerebrospinal fluid of a patient with relapse of cerebral nocardiosis

Nocardia paucivorans represents a new species of the genus Nocardia that has recently been isolated from bronchial secretions of a patient with chronic lung disease. Here, we report on the course of a disseminated infection caused by this species: i.e., cerebral and subsequent meningeal manifestations, isolation from the cerebrospinal fluid, and in vitro susceptibility to various antimicrobial agents.

Primary brain abscess with Nocardia farcinica in an immunocompetent patient

In this paper, we describe a case of an immunocompetent patient with cerebral nocardiosis. The onset was with loss of strength, paresthesia and focal epilepsy of the left arm. MRI showed on T2-weighted sequences a hyperintense central area of pus surrounded by a well-defined hypointense capsule and surrounding edema; on T1-weighted sequences a hypointense necrotic cavity with ring enhancement following administration of intravenous gadolinium. The patient underwent surgical excision of the abscess but culture from the specimen was negative. After 40 days of empirical antimicrobial therapy he developed neurological deterioration with focal epilepsy. A new MRI documented an enlargement of the hypointense lesion in the right frontal-parietal region. A second craniotomy with drainage of the abscess was performed; cultures yielded Nocardia farcinica. Therapy with trimethoprim/sulfamethoxazole, amikacin and meropenem was given for 35 days, and clinical and radiological improvement was observed. Home therapy was done with oral trimethoprim/sulfamethoxazole. Currently, 5 months from the second surgery, the patient can walk with support and no new episodes of epilepsy occurred. Side effects were absent from therapy. The MRI appearance of the brain lesion has improved, with a decrease in size, surrounding edema and ring enhancement.