Clinical Characteristics and Treatment Outcome of Central Nervous System Nocardiosis: A Systematic Review of Reported Cases

Fever of unknown origin revealing testicular nocardiosis: a case report and literature review

BACKGROUND

Nocardia is an ubiquitous soil organism. As an opportunistic pathogen, inhalation and skin inoculation are the most common routes of infection. Lungs and skin are the most frequent sites of nocardiosis. Testis is a highly unusual location for nocardiosis.

CASE PRESENTATION

We report the case of an immunocompromised 75-year-old-man admitted for fever of unknown origin. He presented with skin lesions after gardening and was first suspected of Mediterranean spotted fever, but he did not respond to doxycycline. Then, physical examination revealed new left scrotal swelling that was compatible with a diagnosis of epididymo-orchitis. The patient's condition did not improve despite empirical antibiotic treatment with the onset of necrotic scrotal abscesses requiring surgery. Nocardia brasiliensis yielded from the removed testis culture. High-dose trimethoprim-sulfamethoxazole and ceftriaxone were started. Multiple micro-abscesses were found in the brain and spinal cord on imaging studies. After 6 weeks of dual antibiotic therapy for disseminated nocardiosis, slight regression of the brain abscesses was observed. The patient was discharged after a 6-month course of antibiotics and remained relapse-free at that time of writing these lines. Trimethoprim-sulfamethoxazole alone is meant to be pursued for 6 months thereafter. We undertook a literature review on previously reported cases of genitourinary and urological nocardiosis; to date, only 36 cases have been published with predominately involvement of kidney, prostate and testis.

CONCLUSIONS

To the best of our knowledge, this is the first case of Nocardia brasiliensis simultaneously infecting skin, testis, brain and spinal cord in an immunocompromised patient. Knowledge on uncommon forms of nocardiosis remains scarce. This case report highlights the difficulty of diagnosing atypical nocardiosis and the importance of prompt bacteriological sampling in case of empirical antibiotics failure.

Disseminated nocardiosis presenting as a superinfected thyroglossal duct cyst in a patient with diabetes

We introduce the case of a male patient in his 60s who was admitted to our emergency department with a persisting sore throat for the last 3 weeks and dysphagia. Fibre-endoscopic evaluation revealed an asymmetry at the base of the tongue. In combination with elevated white cell count and C reactive protein, a computerized tomography showed a superinfected thyroglossal duct cyst. Intravenous antibiotics were initiated, and the patient was taken to the operating room for cervicotomy. The microbiological swab taken intraoperatively detected Nocardia paucivorans Additional imaging revealed disseminated nocardiosis with cerebral and pulmonary manifestations.The patient was treated with oral trimethoprim/sulfamethoxazole and, over time, showed complete remission of central nervous system lesions and improvement of pulmonary involvement. Following this, the treatment was stopped 8 months after the initial diagnosis. In this report, we discuss treatment standards and outcomes of nocardiosis based on our management strategies of our patient.

Comparison of Clinical Characteristics and Treatment Outcome Between Localized and Disseminated Nocardiosis in a Tertiary Hospital in China

Background

In China, due to the large population, infections caused by Nocardia may not be as rare. Unfortunately, there is still inadequate knowledge of the clinical impact caused by Nocardia. This study aimed to compare the clinical characteristics and treatment of localized and disseminated nocardiosis.

Methods

The clinical and microbiological data of patients diagnosed with nocardiosis in a tertiary hospital in Beijing from July 2011 to July 2021 were collected and retrospectively analyzed.

Results

Among the 54 nocardiosis cases, 34 cases were in the localized infection group, while 20 cases in the disseminated infection group. The proportion of patients with chronic structural lung disease was higher in the localized group (P=0.010). In contrast, patients with disseminated infections were more prone to receive long-term glucocorticoids and/or immunosuppressants (P=0.027). Pulmonary nodules were prominent features of imaging changes in patients with disseminated infections (P=0.027) whereas bronchial dilatation was more common in patients with localized infections (P=0.025). In addition, the disseminated group had longer average hospitalization days relative to the localized group (P=0.016), but there was no significant difference in mortality between them (P=0.942).

Conclusion

There were differences in the clinical profiles between patients with localized and disseminated nocardiosis in terms of clinical presentation, infection site, radiological features, treatment, and prognosis. These findings may provide references for the management and treatment of patients with nocardiosis.

Brucella infection combined with Nocardia infection: A case report and literature review

Human brucellosis is an infectious disease caused by Brucella and is often misdiagnosed for atypical manifestations including fever of unknown origin, headache, weakness, among else. Nocardiosis is a zoonotic disease caused by the genus Nocardia, which usually spreads through the respiratory tract, skin, and digestive tract. Limited research has documented cases of co-infection involving both Brucella and Nocardia pathogens in patients. A 55-year-old male was admitted to our hospital with intermittent high-grade fever. Following sputum and blood cultures, as well as other laboratory examinations, the patient was diagnosed with concurrent brucellosis and nocardiosis. According to recommendations of previous studies and reports, the patient was successively treated with levofloxacin, doxycycline, piperacillin sodium and sulbactam sodium, trimethoprim-sulfamethoxazole, rifampicin, and tigecycline, after which the patient recovered and was discharged. Brucella and Nocardia are both opportunistic pathogens and simultaneous infection of Brucella and Nocardia is relatively rare. If patients continue to experience persistent fever despite receiving empirical antibiotic therapy, it becomes necessary to conduct examinations to identify potential atypical pathogens, including Brucella and Nocardia. Sputum staining, sputum culture, and blood culture are critical auxiliary examinations during clinical practice. The treatment plan should be selected based on guidelines and the individual patient's condition. Regular reevaluation should be conducted, and antimicrobial agents should be adjusted accordingly.

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.

Clinicopathologic characteristics of Nocardia brain abscesses: Necrotic and non-necrotic foci of various stages

Nocardia brain abscesses are rare bacterial infections associated with a high mortality rate, and their preoperative diagnosis can be difficult for various reasons including a nonspecific clinical presentation. While late-stage nocardial brain abscesses may be radiologically characteristic, early-stage lesions are nonspecific and indistinguishable from another inflammatory/infectious process and other mimics. Despite the paucity of previous histopathological descriptions, histopathological examination is critical for the identification of the pathogen, lesion stage(s), and possible coexisting pathology. In this study, we examined the clinical, radiological and histopathological features of 10 patients with brain nocardiosis. Microscopic findings were analysed in correlation with clinical and radiological features in 9 patients, which revealed that brain nocardiosis was characterized by numerous necrotic and non-necrotic foci of various stages (I-IV) along with Nocardia identification, as well as the leptomeningeal involvement in most cases, and co-infection of brain nocardiosis with toxoplasmosis in 2 patients. The imaging features were characteristic with a multilobulated/bilobed ring-enhancing appearance in 8 patients including 2 patients with multiple lobulated and non-lobulated lesions and 1 patient showing the progression from a non-lobulated to lobulated lesion. These findings suggest that nocardial brain abscesses particularly at late-stages share common characteristics. Nevertheless, given the complex pathologic features, including possible co-infection by other pathogens, nocardial brain abscesses remain a therapeutic challenge.

Clinical and Radiological Characterization of Central Nervous System Involvement in Nocardiosis: A 20-Year Experience

Background This study aimed to present the clinical and radiological characteristics and the outcomes of patients with Nocardia infection of the central nervous system (CNS). Methodology We conducted a retrospective review of patients aged 18 and older admitted between August 1998 and November 2018 with culture-proven nocardiosis and CNS involvement. Results Out of 110 patients with nocardiosis, 14 (12.7%) patients had CNS involvement. The median age was 54.5 (27, 86) years, and 12 (85.7%) patients were male. Overall, 12 (85.7%) patients were immunosuppressed on high doses of glucocorticoids; seven (50%) patients were solid organ transplant recipients. Only eight (57.1%) patients had neurological symptoms at presentation, and the rest were diagnosed with CNS involvement after imaging surveillance. Three distinct radiologic patterns were identified, namely, single or multiple abscesses, focal cerebritis, and small, septic embolic infarcts. All isolates of Nocardia were susceptible to trimethoprim/sulfamethoxazole and amikacin, with susceptibility to linezolid and carbapenems being 90.9% and 79.5%, respectively. Despite receiving antibiotic therapy, six (42.8%) patients died, most of them within weeks of initial admission. All surviving patients underwent prolonged antimicrobial therapy until the resolution of MRI abnormalities. All solid organ transplant recipients recovered. Conclusions Nocardia CNS infection was a rare condition, even among a large, immunosuppressed patient population. CNS imaging surveillance is paramount for immunosuppressed patients with nocardiosis, as CNS involvement influences the choice and duration of therapy. Nocardia antibiotic susceptibility varied widely between strains and the empiric therapy should consist of multiple classes of antimicrobials with CNS penetration. Mortality was high, but all solid organ transplant recipients recovered.

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.

The epidemiology, clinical presentation and treatment outcomes in CNS actinomycosis: a systematic review of reported cases

BACKGROUND

CNS actinomycosis is a rare chronic suppurative infection with non-specific clinical features. Diagnosis is difficult due to its similarity to malignancy, nocardiosis and other granulomatous diseases. This systematic review aimed to evaluate the epidemiology, clinical characteristics, diagnostic modalities and treatment outcomes in CNS actinomycosis.

METHODS

The major electronic databases (PubMed, Google Scholar, and Scopus) were searched for the literature review by using distinct keywords: "CNS" or "intracranial" or "brain abscess" or "meningitis" OR "spinal" OR "epidural abscess" and "actinomycosis." All cases with CNS actinomycosis reported between January 1988 to March 2022 were included.

RESULTS

A total of 118 cases of CNS disease were included in the final analysis. The mean age of patients was 44 years, and a significant proportion was male (57%). Actinomycosis israelii was the most prevalent species (41.5%), followed by Actinomyces meyeri (22.6%). Disseminated disease was found in 19.5% of cases. Most commonly involved extra-CNS organs are lung (10.2%) and abdomen (5.1%). Brain abscess (55%) followed by leptomeningeal enhancement (22%) were the most common neuroimaging findings. Culture positivity was found in nearly half of the cases (53.4%). The overall case-fatality rate was 11%. Neurological sequelae were present in 22% of the patients. On multivariate analysis, patients who underwent surgery with antimicrobials had better survival (adjusted OR 0.14, 95% CI 0.04-0.28, p value 0.039) compared to those treated with antimicrobials alone.

CONCLUSION

CNS actinomycosis carries significant morbidity and mortality despite its indolent nature. Early aggressive surgery, along with prolonged antimicrobial treatment is vital to improve outcomes.

Co-infection with Mycobacterium tuberculosis and Nocardia farcinica in a COPD patient: a case report

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a common respiratory disease characterized by persistent airflow limitation. Infection with either Mycobacterium tuberculosis or Nocardia in COPD patients has been reported. However, co-infection with Mycobacterium tuberculosis and Nocardia is rare. Herein, we described such a patient with COPD in a primary hospital, and the diagnosis process.

CASE PRESENTATION

A 79-year-old female farmer with COPD was consecutively admitted to two hospitals with chief complaints of worsening cough, sputum and gasping since January10, 2022. Microbiological examination was not performed at the first hospital due to unknown reasons, and empirical antibiotic treatment was not effective. The patient was subsequently referred to our hospital. After screening the source of infection and the pathogen, she was diagnosed with tuberculosis. However, the patient did not benefit from antituberculosis treatment, with no remission of respiratory tract symptoms. Cerebrospinal fluid and bronchoalveolar lavage fluid specimens were subsequently sent for microbiological examination. The results indicated Mycobacterium tuberculosis and Nocardia.spp. After four days of bacterial culture, Nocardia.spp grew on medium, and Nocardia.farcinica was identified by the MALDI-TOF MS system and 16 s RNA. The patient was prescribed trimethoprim sulfamethoxazole (TMP/SMX) in combination with anti-tuberculosis drugs to treat the co-infection. She showed gradual improvement and was discharged from the hospital on February 19, 2022. However, the follow-up results were unclear.

CONCLUSIONS

Co-infection with Nocardia and Mycobacterium tuberculosis should be considered in COPD patients. Repeated microbiological and microscopy examinations are essential in primary hospitals.

Meningitis and spondylodiscitis due to Nocardia nova in an immunocompetent patient

BACKGROUND

Disseminated nocardiosis is a very rare disease. By now only few cases of meningitis and spondylodiscitis have been reported. To our knowledge, this is the first case of meningitis caused by Nocardia nova.

CASE PRESENTATION

We report on a case of bacteraemia, meningitis and spondylodiscitis caused by N. nova in an immunocompetent patient. We describe the long, difficult path to diagnosis, which took two months, including all diagnostic pitfalls. After nocardiosis was diagnosed, intravenous antibiotic therapy with ceftriaxone, later switched to imipenem/cilastatin and amikacin, led to rapid clinical improvement. Intravenous therapy was followed by oral consolidation with co-trimoxazole for 9 months without any relapse within 4 years.

CONCLUSIONS

Establishing a diagnosis of nocardiosis is a precondition for successful antibiotic therapy. This requires close communication between clinicians and laboratory staff about the suspicion of nocardiosis, than leading to prolonged cultures and specific laboratory methods, e.g. identification by 16S rDNA PCR.

A case report of pulmonary nocardiosis during pembrolizumab: the emerging challenge of the infections on immunotherapy

The increasing occurrence of infectious complications during immune checkpoint inhibitor (ICI) therapy is an emerging challenge for oncologists. ICIs can reverse T-cell exhaustion, and this may lead to hyperinflammatory dysregulated immunity with subsequent potentially fatal infections. Nocardia spp. are opportunistic pathogens belonging to aerobic Actinomycetes. The authors report a case of Nocardia pneumonia in a 62-year-old male with oral squamous cell carcinoma and lung cancer while taking pembrolizumab. The patient did not take corticosteroids or other immunosuppressant medications. Since ICIs are able to stimulate the immune response, the authors hypothesize that immune reconstitution inflammatory syndrome due to pembrolizumab might cause this opportunistic infection.