Nocardia farcinica Brain Abscess in an Immunocompetent Host With Pulmonary Alveolar Proteinosis: A Case Report and Review of the Literature

How an Antimicrobial Stewardship Team Treated a Nocardia farcinica-Associated Brain Abscess: A Case Report

Nocardia species, which are ubiquitous in the environment, form lesions primarily in immunocompromised patients via oral or cutaneous infection. Some of these Nocardia species, such as N. farcinica, also infect the central nervous system via hematogenous dissemination, which rarely results in brain abscesses. Notably, N. farcinica is resistant to numerous antimicrobial drugs used in empirical therapy, necessitating the intervention of an infectious disease specialist. To date, no case of antimicrobial stewardship teams (ASTs) playing a central role in community hospitals without an infectious disease specialist has been reported. Here, we describe a case of N. farcinica-associated brain abscess in a small-to-medium-sized hospital with no infectious disease department or specialist, in which the AST assisted in the identification of the causative organism and in selecting appropriate therapeutic agents, ultimately leading to a cure. The patient was an 88-year-old man with a high fever. He had been taking prednisolone (10-15 mg/day) for approximately 1 year for pemphigoid. Considering the possibility of fever owing to bacteremia of cutaneous origin, ampicillin/sulbactam antimicrobial therapy at 6 g/day was initiated. A subsequent close examination led to the diagnosis of a brain abscess. Emergency abscess drainage was performed by a neurosurgeon, and postoperative antimicrobial combination therapy comprising ceftriaxone (4 g/day), vancomycin (2 g/day), and metronidazole (1,500 mg/day) was commenced. The AST suspected Nocardia infection earlier, but further testing was difficult to perform at this facility. Therefore, by requesting assistance from Nagoya University Hospital, we performed early bacterial identification by mass spectrometry and appropriate antimicrobial susceptibility testing by a custom panel on day 11. The patient was non-responsive to all the previously used antibiotics at the time of admission. On day 13 after admission, the patient was successfully treated with trimethoprim-sulfamethoxazole (TMP-SMX) and imipenem/cilastatin sodium, and the patient was cured. The AST can be as effective as an infectious disease specialist when a strong working relationship is established between the team and clinicians. Further, the activities of the AST can improve patient survival via active medical support in collaboration with attending physicians.

Cerebral Abscess Infected by Nocardia gipuzkoensis

Purpose

Nocardia gipuzkoensis is a novel species that solely identified in patients with pulmonary infections by far. Growing evidence showed the excellent performance of metagenomics next-generation sequencing (mNGS) on pathogenic identification, especially for new species. Here, we described the first case of an elderly female patient suddenly suffering from neurological disorders owing to N. gipuzkoensis infection. And linezolid could effectively treat N. gipuzkoensis infection.

Patients and Methods

The results of imaging, laboratory cultures, and mNGS, as well as therapeutic process are shared.

Results

An elderly female patient suddenly suffered from neurological disorders with dysphasia and right limb trembles under no obvious causes. Subsequently, she was diagnosed as intracranial space-occupying lesions by magnetic resonance imaging (MRI). The isolate from brain secretion was further identified as N. gipuzkoensis through mNGS. The targeted therapy with linezolid according to the antimicrobial susceptibility was used to treat cerebral abscess induced by N. gipuzkoensis. During the follow-up, no relapse was observed for the patient after surgery for 104 days.

Conclusion

Cerebral abscess induced by N. gipuzkoensis is rare disorder with high mortality. mNGS has been identified as a promising tool in pathogen diagnosis for timely therapy. Linezolid as one of the antimicrobial drugs could effectively treat N. gipuzkoensis infection and prevent adverse outcomes.

Brain Abscess Caused by Nocardia farcinica in a Young Immunocompetent Patient

Cerebral nocardiosis is a rare opportunistic infectious disease that occurs mainly in immunocompromised hosts; however, immunocompetent patients may be affected too. It often results in the formation of intraparenchymal brain abscess, which represents only 2% of all cerebral abscesses. The overall mortality rate exceeds 20% in immunocompetent patients and 55% in immunocompromised patients. Bacteriological diagnosis is often confirmed only after the surgical excision of the abscess. Thus, the initiation of effective therapy is frequently delayed. Our goal is to highlight a diagnostic approach to cerebral nocardiosis in an immunocompetent patient with the purpose of accelerating the initiation of the appropriate therapy. We report a rare case of brain abscess caused by Nocardia farcinica in a 39-year-old male, a resident of New York City, USA, with a past medical history of intravenous (IV) drug use, who was admitted for altered mental status. The patient was cachectic and ill-appearing. Initial laboratory tests showed neutrophilic leukocytosis. Computed tomography (CT) of the head revealed a large ill-defined multilobulated mass of size 6 × 5 × 4.5 cm in the right cerebral hemisphere, which was confirmed with magnetic resonance imaging (MRI). The hospital course was complicated by the deterioration of mental status requiring endotracheal intubation. The patient underwent a right-sided hemicraniectomy; a wound culture identified Nocardia farcinica. The patient was started on intravenous (IV) Bactrim, which caused an allergic reaction. Thus, he was switched to IV imipenem-cilastatin. After E-test was performed, the patient was switched to oral linezolid. The initiation of targeted antibiotic therapy was crucial for the management of this patient and resulted in a good clinical outcome. In conclusion, cerebral nocardiosis, being an unusual and a potentially fatal infection, should be considered in the differential diagnosis of brain abscess even in immunocompetent hosts. Prompt bacteriological diagnosis helps to initiate a specific antimicrobial therapy. Long-term antimicrobial therapy and long-term follow-up are necessary to prevent relapse.

Cryptogenic Organizing Pneumonia Complicated With Cutaneous Disseminated Nocardia Infection: A Case Report and Literature Review

Nocardia disease is a rare opportunistic infection that usually occurs in individuals with solid organ transplantation, malignant tumors, human immunodeficiency virus (HIV) infection, or chronic lung disease history. Here, we reported a rare case of cryptogenic organizing pneumonia (COP) combined with disseminated Nocardia infection. A 75-year-old man was admitted to the respiratory department due to weakness and poor appetite for 3 months. The chest CT scan showed dense patchy shadows in the dorsal lower lobe of both lungs. After the transbronchial lung biopsy, the histopathological findings supported the diagnosis of COP. During the period of glucocorticoid reduction (oral methylprednisolone tablets 24 mg one time a day), the patient presented with masses on the back and bilateral upper limbs and intermittent fever for 3 days. After admission, the patient underwent a series of examinations and an ultrasound puncture of the mass. The puncture fluid was caseous necrosis, which was confirmed to be Nocardia infection after bacterial culture, so the diagnosis was disseminated Nocardia infection. After 13 days of admission, the patient developed a headache, accompanied by decreased visual acuity and blurred vision. An imaging (enhanced brain CT) examination revealed intracranial space-occupying lesions. The neurosurgeon was consulted and performed transcranial abscess puncture and drainage, intravenous antibiotics (meropenem, etc.) for 2 months, and trimethoprim/sulfamethoxazole (TMP-SMX) for 6 months. The patient was followed up for 3 years and has remained relapse-free. The mortality rate of disseminated Nocardia infection is as high as 85%, especially when combined with brain abscesses. Therefore, timely diagnosis and correct treatment are crucial for the prevention of fatal consequences. The report of this case can enable more patients to receive early diagnosis and effective treatment, so as to obtain a satisfied prognosis.

Membranous Nephropathy Complicated with Disseminated Nocardia farcinica Infection: A Case Report and Literature Review

Disseminated infection caused by Nocardia farcinica with primary nephrotic syndrome is exceedingly rare. A 66-year-old female visited the outpatient department due to fever and fatigue who had been diagnosed as membranous nephropathy and with a long-term prednisone and immunosuppressive therapy. After lung biopsy for many times, culture from space-occupying lesion of the right lung and species identification by mass spectrometry-based methods (MALDI-TOF) revealed Nocardia farcinica. By imaging examination, space-occupying lesions from the lungs, brain, abdominal cavity and kidney were found. After 2 weeks of meropenem intravenous and up to 6 months of trimethoprim-sulfamethoxazole (TMP-SMX) therapy, our patient has remained relapse-free at that time of writing. Disseminated infection caused by Nocardia farcinica is usually subacute with complex clinical manifestations. In addition, it can be easily confused with diseases such as tumor and mycobacterial infection, and lead to fatal consequences. Therefore, we hope that we can remind clinicians considering by discussing common features of disseminated Nocardia farcinica infection.

A case report of brain abscess caused by Nocardia farcinica

Background

Brain abscess due to the Nocardia genus is rarely reported and it is usually found in immunocompromised patients. Treatment of Nocardia brain abscess is troublesome and requires consideration of the severity of the underlying systemic disease. The difficulties in identifying the bacterium and the frequent delay in initiating adequate therapy often influence the prognosis of patients.

Case presentation

Here, we report a rare case of brain abscess caused by Nocardia farcinica. The patient’s medical history was complicated: he was hospitalized several times, but no pathogens were found. At last, bacteria were found in the culture of brain abscess puncture fluid; the colony was identified as Nocardia farcinica by mass spectrometry. Targeted antibiotic treatment was implemented, brain abscess tended to alleviate, but the patient eventually developed fungal pneumonia and died of acute respiratory distress syndrome (ARDS).

Conclusion

Brain abscess caused by Nocardia farcinica can appear in non-immunocompromised individuals. Early diagnosis, reasonable surgical intervention, and targeted antibiotic treatment are critical for Nocardia brain abscess treatment. In the treatment of Nocardia brain abscess, attention should paid be to the changes in patients’ immunity and infection with other pathogens, especially fungi, avoided.