Pulmonary nocardiosis: a comparative analysis of Nocardia asteroides and non-asteroides species.

Our study compares the risk factors, clinical presentations and outcomes of pulmonary infections caused by Nocardia asteroides and non-asteroides species. We performed a retrospective cohort study comparing pulmonary infections by both species in patients presenting to a tertiary care hospital in Karachi, Pakistan. Forty-one patients were identified with pulmonary nocardiosis, with 58.5% belonging to the N. asteroids complex. The most common clinical findings were fever and a cough for both groups, with lobar infiltrates being the most common finding on chest radiographs. In vitro testing showed a sensitivity of all species to trimethoprim-sulfamethoxazole (TMP-SMZ), aminoglycosides, ceftriaxone and imipenem. The majority of the patients were treated with TMP-SMZ in combination with other drugs. The results of our study suggest that there is no significant difference in the risk factors, presentations and outcomes of pulmonary infections by N. asteroides and non-asteroides species. Immunocompromised patients are more likely to have unfavorable outcomes.

Linezolid como tratamiento de la infección por Nocardia asteroides / Linezolid as treatment of Nocardia asteroides infection

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Sepsis grave por Nocardia asteroides en paciente con tratamiento corticoideo prolongado / Severe sepsis induced by Nocardia asteroides in a patient with prolonged corticosteroid treatment

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Nocardia brain abscesses in a male patient with SLE: successful outcome despite delay in diagnosis.

We report a 37-year-old African-American man with systemic lupus erythematosus (SLE) diagnosed in May 2001 when he presented with biopsy-proven nephritis. He had been treated intermittently from May 2001 to November 2004 with intravenously (i.v.) administered cyclophosphamide and high doses of prednisone due to unrelenting proteinuria. In November 2004, he was admitted to the hospital because of deterioration of renal function and massive proteinuria (21 g dl(-1) 24 h(-1)) and treated with pulses of methylprednisolone and two courses of i.v. administered cyclophosphamide. His hospital course was complicated by cellulitis and bacteremia with Pseudomonas spp. and Streptococcus bovis. He was discharged on prednisone 60 mg daily, ciprofloxacin, augmentin, and hemodialysis. He was readmitted a week later with new onset of seizure activity, slurred speech, and left-sided hemiparesis. Magnetic resonance imaging of the brain revealed multiple ringlike enhancing foci in the frontal and occipital lobes. Brain biopsy was performed, and Gram stain and initial cultures were negative. Empiric tobramycin, cefepime, and metronidazole were administered. Diagnosis was delayed for several months, but culture eventually grew Nocardia asteroides. Trimethoprim-sulfomethoxazole and linezolid therapy was begun. This was followed by slow, but steady, clinical improvement. Risk factors, diagnostic clues, and treatment are reviewed.

[Cutaneous nocardiosis as an opportunistic infection]. / Cutane nocardiose als opportunistische infectie.

A 46-year-old man who had been treated with azathioprine and budesonide for Crohn's disease for the past eight years developed a purulent skin condition on the right ring finger. Despite surgical drainage and treatment with amoxicillin and flucloxacillin, the condition spread itself over the hand and lower arm, partly per continuum and partly in jumps. The patient did not feel ill and there were no systemic symptoms. Ultimately, Nocardia asteroides was cultured from the wound and complete cure was achieved after 8 months' treatment with co-trimoxazole. Infections with Nocardia spp. are rare but may occur more often and run a more fulminant course in patients under treatment with immunosuppressants. Cutaneous nocardiosis generally has a characteristic lymphogenous spreading pattern, but an atypical picture with pustules, pyoderma, cellulitis or abscess formation is also possible. In non-cutaneous nocardiosis there is usually pneumonia or lung abscess, possibly with secondary haematogenous spread to the central nervous system or skin. Culturing Nocardia requires more time than usual but can be promoted by special culture media. Treatment of the infection with co-trimoxazole is the method of choice and is almost always successful in cases of cutaneous nocardiosis.

ICD nocardiosis.

We present an initial report of Nocardia asteroides implantable cardioverter defibrillator infection. Systemic infection persisted despite pulse generator explant and several years of appropriate antibiotic therapy. Without epicardial lead system removal, chronic pleuropericardial disease developed.

Neuroinvasive Nocardia asteroides GUH-2 induces apoptosis in the substantia nigra in vivo and dopaminergic cells in vitro.

Neurodegenerative diseases such as Parkinson's disease are increasingly prevalent in the aging population worldwide. The causes of these disorders are unknown, but many studies have suggested that the etiology is likely multifactorial and may involve exposure to something in the environment combined with the normal aging process. Nocardia asteroides are bacteria commonly found in the soil, and neuroinvasive strains of nocardiae have been described. N. asteroides strain GUH-2 invades the brains of experimentally infected animals and selectively affects dopaminergic neurons of the substantia nigra (SN), causing an L-DOPA-responsive movement disorder resembling parkinsonism. Furthermore, dopaminergic neurons undergo morphological changes characteristic of apoptosis following nocardial infection. Apoptosis has been implicated in dopaminergic neuronal dropout in Parkinson's patients as well as other parkinsonian models. Thus, in this study, in vivo and in vitro models were utilized to measure the ability of GUH-2 to induce the apoptotic death of dopaminergic cells. Following infection with GUH-2, dopaminergic apoptotic cells were identified in the SN of animals by in situ end labeling, which detects DNA fragmentation, combined with fluorescent immunolabeling of tyrosine hydroxylase-positive cells. In addition, apoptosis was observed in PC12 cell cultures incubated with GUH-2 by both in situ end labeling and the annexin V assay, which detects externalization of phosphatidylserine of the plasma membrane, indicating apoptotic death. Based on the results of these studies, it appears that experimental infection with N. asteroides provides a general model for studying apoptosis in parkinsonian disorders.

Pulmonary nocardiosis in a non-Hodgkin's lymphoma patient.

Nocardiosis is an opportunistic infection especially in immunocompromised patients. Lungs are the most common infection sites and therapy poses some difficulties. We describe a case of pulmonary infection with Nocardia asteroides in a non-Hodgkin's lymphoma patient. Although the mortality from pulmonary nocardiosis is high in immunocompromised patients, our patient was successfully treated with trimethoprim-sulfamethoxazole (TMP/SMZ) and amikacin. Maintenance therapy with TMP/SMZ was continued for 1 year. This case supports the importance of the long-term maintenance treatment after the initial combination therapy.

Disseminated Nocardia asteroides and coinfection with Trichophyton rubrum in a renal transplant recipient.

Disseminated Nocardia infection has a high mortality and morbidity rate in solid organ transplant recipients, even when appropriate antibiotics are given. In this report a renal transplant recipient is described, who developed disseminated Nocardia asteroides infection with lung, eye, and brain involvement, in addition to coinfection with Trichophyton rubrum.

Site-specific invasion of the basal ganglia by Nocardia asteroides GUH-2.

Nocardia asteroides GUH-2 (GUH-2) invades the nigrostriatal region of the brain in mice [15]. Selective dopaminergic neuronal dropout in the substantia nigra results in parkinsonian changes characterized by movement disorders responsive to L-dopa [15]. This is the only reported example of an experimental bacterial model for parkinsonism. Following i.v. inoculation of GUH-2 into the non-human primate Macaca fasicularius, the nocardiae preferentially invaded and grew within the basal ganglia (substantia nigra, caudate, putamen, and globus pallidus) often without inducing apparent inflammation. Reduced, limited growth of nocardiae occurred in the white matter of the cerebral cortex, medulla, and hippocampus, whereas neither significant adherence to nor growth within the meninges was observed. Twenty-four hours after injection, nocardial cells were found within capillary endothelial cells, the basal lamina, neurons, astroglia and in axonal extensions. The bacteria, in endothelial cells, were surrounded by a unit membrane, but in the basal lamina they appeared to be free and not membrane bound. After the organisms passed into the brain parenchyma, the nocardiae once again became surrounded by membrane, often being encapsulated by numerous layers with the innermost layer tightly adherence to the bacterial surface. There was a propensity for nocardial growth within and along myelinated axons, either with or without disruption to the surrounding myelin sheath. There was electron microscopic evidence that the nocardiae induced a neurodegenerative response especially in the substantia nigra region. Thus, the early interactions of GUH-2 within the primate brain appeared to be similar to those reported in the mouse.

Nocardiosis cutánea primaria / Primary cutaneous nocardiosis

Se presenta un paciente de 71 años, de sexo masculino, con nocardiosis cutánea primaria por Nocardia asteroides. Se describen las formas clínicas de nocardiosis cutánea, así como los tratamientos que pueden efectuarse

Nocardiosis cutánea primaria / Primary cutaneous nocardiosis

Se presenta un paciente de 71 años, de sexo masculino, con nocardiosis cutánea primaria por Nocardia asteroides. Se describen las formas clínicas de nocardiosis cutánea, así como los tratamientos que pueden efectuarse (AU)

Monoamine changes in the brain of BALB/c mice following sub-lethal infection with Nocardia asteroides (GUH-2).

BALB/c mice injected intravenously with a single, sub-lethal dose of Nocardia asteroides GUH-2 develop several levodopa responsive movement disorders. These included headshake, stooped posture, bradykinesia, and hesitation to forward movement. The changes in monoamine levels in the brain of these mice were determined. There was a significant loss of dopamine with greatly increased dopamine turnover in the neostriatum 7 to 29 days after infection. These effects were specific for dopaminergic neurons since minimal changes were found in neostriatal norepinephrine and serotonin even though serotonin turnover was increased. Changes in monoamine metabolism were not limited to the neostriatum. There were reduced levels of serotonin and norepinephrine with increased serotonin turnover in the cerebellum. One year after infection, dopamine metabolism had returned to near normal levels, but many of the movement disorders persisted. Specific changes in neurochemistry did not always appear to correspond with these impairments. Nevertheless, these data are similar to those reported in MPTP treated BALB/c mice.

Infección por nocardia asteroides en un paciente con lupus eritematoso sistémico / Nocardia asteroides infection in a patient with systemic lupus erythematosus

Nocardia asteroides infection are unusually observed in sistemic Lupus erithematous (SLE) patients. They are generally associated to steroidal and immunosuppressive therapy. We report a 24 years old female with SLE diagnosed in 1994 who developed a severe preeclampsia in her first pregnancy requiring emergency caesarean section. Post partum acute renal failure and type IV lupus nephropathy were treated with hemodialysis, metilprednisolone, cyclophosphamide and prednisone. Three months later, while she was receving the fourth cyclophosphamide dose, she presented with a pleuro pneumonia and occipital abscess, both caused by Nocardia asteroides. She was treated with cotrimoxazole + cefixime and pleural decortication was required. Five months later, she developed Meningitis caused by Nocardia asteroides and hydrocephalus. She was treated with ceftriaxone, vancomycin, cotrimoxazole and ventricular shunting procedure. Two months later, a retroperitoneal abscess was diagosed and surgically drained but the patient died, due to a methicillin-resistant Staphylococcus aureus septicemia