First report of Nocardia beijingensis infection in an immunocompetent host in the United States

Brain abscesses: the first report of disseminated Nocardia beijingensis infection in an immunocompetent individual in China

Nocardia is widely distributed in the natural environment and typically cause opportunistic infections. However, it is important to note that the pathogenicity of different Nocardia species may vary significantly. Here we reported the first case of brain abscess caused by Nocardia beijingensis (N. beijingensis) infection in China. A 70-year-old male immunocompetent individual came to our hospital for treatment due to headache. After examination, it was found that he had a brain abscess caused by N. beijingensis. By utilizing a combination of surgical intervention and antibiotic therapy, the patient ultimately achieved full recovery. In addition, we isolated this strain and displayed its ultrastructure through scanning electron microscopy. The phylogenetic tree was analyzed by 16 S rRNA sequence. A literature review of N. beijingensis infections in all immunocompetent and immunocompromised patients was presented. It highlighted that abscess formation appears to be a common manifestation of N. beijingensis infection, and N. beijingensis has become an emerging pathogen in immunocompetent individuals.

A Rare Case Report of Disseminated Nocardia Farcinica Granulomatous Hepatitis and Clinical Management Experience

Background

Nocardiosis is primarily an opportunistic infection affecting immunocompromised individuals, with a predilection for the lungs, brain, or skin in those with compromised immune function. Granulomatous hepatitis caused by Nocardia is a rare clinical manifestation. This study aims to provide a systematic overview of the clinical features of Nocardiosis caused by Nocardia farcinica, enhancing our understanding of this disease.

Methods

We report a case of a 75-year-old male with no underlying diseases presenting with a history of "recurrent fever for more than 4 months", along with fatigue, poor appetite, and pleural and abdominal effusion. Despite treatment at multiple hospitals, the patient showed little improvement. Chest CT revealed chronic inflammation, small nodules, bilateral pleural effusion, and pleural thickening. Abdominal CT indicated multiple low-density lesions in the liver, multiple small calcifications, and abdominal effusion.

Results

Liver biopsy suggested inflammatory changes, with focal granuloma formation. Metagenomic next-generation sequencing (mNGS) of liver tissue indicated Nocardia farcinica, leading to the final diagnosis of disseminated Nocardia farcinica granulomatous hepatitis.

Conclusion

Nocardia infection is a rare disease primarily observed in immunocompromised patients but can also occur in those with normal immune function. The clinical and radiological features lack specificity; however, the utilization of mNGS technology enables rapid identification of the pathogenic microorganism. Nocardia farcinica is generally susceptible to sulfonamide drugs and amikacin, offering viable treatment options.

Persistent Nocardia beijingensis infection in a patient with postoperative abscess and misuse of antibiotics in China

Here we describe the first case of abscess infection caused by Nocardia beijingensis in China. The patient was immunocompetent but suffered from postoperative abscess for 6 years. This study highlights the necessity of long-term infected foci to be thoroughly examined to identify the pathogen, as well as the importance of accurate Nocardia identification and antimicrobial susceptibility tests for understanding the pathogen's epidemiology, clinical significance, and treatment strategy.

Case report: Nocardia farcinica pneumonia in early-stage post liver transplantation

Background

Liver transplantation is a well-established treatment for end-stage liver disease. The evolution of immunosuppressants has supported the recent advances in this field. However, this leads to immunosuppression and increases the risk for infections. Nocardia is an aerobic gram-positive bacillus, which can cause multi-systemic or multi-organ infections. Nocardia is an opportunistic pathogen that principally affects immunosuppressed patients.

Case presentation

Herein, we present a case of Nocardia farcinica pneumonia in a patient at early-stage post-liver transplantation. Following appropriate microbiological tests and imaging, the diagnosis was finally confirmed. A full recovery was achieved after optimal antibiotic therapy of sulfamethoxazole, minocycline, and amikacin.

Conclusions

Nocardia farcinica pneumonia is a rare and life-threatening disease, especially in patients after liver transplantation. Imaging and microbiological tests are helpful for the early diagnosis of the disease. Trimethoprim-sulfamethoxazole (TMP-SMX) as part of first-line therapy for nocardiosis is recommended.

Nocardia beijingensis isolated from an adrenal abscess in a diabetic host

We describe the case of a 57-year-old man with poorly controlled type 2 diabetes mellitus who presented with 30 days of left-sided abdominal pain. He was found to have a left adrenal abscess and underwent adrenalectomy. Intraoperative cultures grew Nocardia beijingensis, which is an uncommonly identified Nocardia species rarely affecting immunocompetent patients. We review the published literature on cases of N. beijingensis among immunocompetent patients. This is the first report summarizing the diagnosis and management of N. beijingensis isolated from an adrenal abscess.

Brain Abscess Caused by Nocardia farcinica and Diagnosed by Metagenomic Next-Generation Sequencing: A Case Report

Background

Brain abscesses caused by Nocardia farcinica are rare and difficult to diagnose. Conventional methods for diagnosing Nocardia species include blood culture, microscopy, and tissue slice, but the performance is not satisfied. We report a case of brain abscess due to N. farcinica diagnosed by metagenomic next-generation sequencing (mNGS).

Case Presentation

We report a case of a 58-year-old man with brain abscess caused by N. farcinica. The patient had a history of pemphigus and required long-term methylprednisolone administration. No pathogen was detected in blood culture, cerebrospinal fluid (CSF) culture, and fast-acid staining. mNGS identified N. farcinica in the CSF. The symptoms and signs of the patient were significantly improved after changing the antibiotics accordingly to sensitive antibiotics.

Conclusion

Metagenomic next-generation sequencing (mNGS) is helpful for early diagnosis and subsequent treatment of Nocardia-associated meningitis and encephalitis, avoiding brain surgery. Early and accurate diagnosis and prompt antibiotic treatment reduced its mortality.

Disseminated nocardiosis in an immunocompetent host with occupational exposure

Nocardia is a genus of Gram-positive, partially acid-fast bacteria consisting of over 120 species, of which 50 are recognized as human pathogens. Nocardia spp. are common colonizers in the environment, particularly in soil and water. Nocardia spp. typically cause opportunistic infections in the immunocompetent host, although cases of nocardiosis have been described in those with a normal immune system. Nocardiosis can be localized, most often in the skin or lung, or be disseminated, with involvement of the brain, bone, and visceral organs. Treatment of nocardiosis is complex, as multiple culture-directed antibacterials with appropriate tissue penetration may need to be used for a prolonged duration. To our knowledge, we describe the first successfully treated case of disseminated Nocardia beijingensis infection in an immunocompetent host with doxycycline and trimethoprim-sulfamethoxazole and hypothesize that his occupational exposure to ubiquitous saprophytes may have led to his infection.

The Role of 18-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (FDG-PET/CT) in Management of Nocardiosis: A Retrospective Study and Review of the Literature

Introduction

18-Fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) is a well-established tool for managing metastatic infections. Nocardiosis, a primarily pulmonary infection, disseminates at high rates. Routine imaging includes chest CT and brain imaging. We examined the use of FDG-PET/CT in nocardiosis and assessed its contribution to diagnosis and management.

Methods

A retrospective study in two tertiary medical centers during 2011–2020. Individuals with nocardiosis for whom FDG-PET/CT was implemented for any reason were included and their medical records were reviewed. A board-certified nuclear medicine physician independently reviewed all scans. Additionally, a systematic review was conducted according to the PRISMA guidelines, to extract data from publications reporting FDG-PET/CT use for the management of nocardiosis.

Results

FDG-PET/CT contributed to the management of all seven patients who met inclusion criteria. It assisted in ruling out an underlying malignancy (29%, 2/7); establishing a wide infection extent (57%, 4/7); and affecting decisions regarding treatment (57%, 4/7), including drug regimen, oral step-down, and duration of therapy. We identified 20 published case reports on this topic. In 80% (16/20), FDG-PET/CT contributed to the management of nocardiosis similar to our study. In addition, in most of the literature cases, FDG-PET/CT guided the diagnostic biopsy.

Conclusion

FDG-PET/CT is valuable in the diagnosis and management of individuals with nocardiosis. The contribution of incorporating FDG-PET/CT to the management of individuals with nocardiosis and its role in monitoring treatment response and shortening treatment duration should be evaluated in prospective studies.

Stroke like presentation of disseminated CNS Nocardia beijingensis infection in an immunocompetent patient: Case report and review of the literature

We describe a rare case of pulmonary and central nervous system (CNS) Nocardia beijingensis infection in an immunocompetent patient presenting with stroke like symptoms and newly discovered pulmonary and brain mass. Initial work up suggested lung cancer with metastasis to the brain. However, further evaluation revealed disseminated N. beijingensis. A literature review of N. beijingensis infections in immunocompetent host is also presented.

Nocardia beijingensis lung mass in an immunocompetent adult

A 47-year-old man was referred for ongoing workup of an enlarging lung mass. Extensive workup of the mass had been unrevealing for several months until cultures grew Nocardia beijingensis He was successfully treated with trimethoprim/sulfamethoxazole and then doxycycline with near-complete resolution of the mass on follow-up. This case presents a rare species of N. beijingensis It highlights the importance of considering nocardiosis in immunocompetent adults and the challenge in initiating targeted treatment due to delayed culture results.

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.

Disseminated Nocardia beijingensis Infection in an Immunocompetent Patient

Nocardia is a genus of aerobic, non-motile and non-spore-forming filamentous branching bacteria with fragmentation into bacillary or coccoid forms. Infections caused by Nocardia often occur in immunocompromised hosts and are potentially life-threatening. Nocardia beijingensis has rarely been reported to cause infection in immunocompetent hosts. We present a case of disseminated infection due to Nocardia beijingensis in a patient with no known medical comorbidities, who presented with new-onset seizure. Another interesting finding in our case is that our patient did not have any pulmonary symptoms despite chest CT showing the pulmonary system as the likely primary site of infection. As per our literature review, this is the seventh reported case of infection due to Nocardia beijingensis in an immunocompetent host.

LEARNING POINTS

To recognize Nocardia beijingensis, a slow-growing weakly acid-fast filamentous bacteria commonly causing opportunistic infections in immunocompromised hosts, as an emerging pathogen in immunocompetent patients.Tissue biopsy with Gram staining showing variable filamentous bacteria and confirmation of species using restriction enzyme analysis and 16S rRNA analysis is needed to establish a diagnosis of infection.Trimethoprim/sulfamethoxazole has been successfully used to treat infection due to Nocardia beijingensis.

Efficient differentiation of Nocardia farcinica, Nocardia cyriacigeorgica and Nocardia beijingensis by high-resolution melting analysis using a novel locus

Accurate identification of Nocardia species remains a challenge due to the complexities of taxonomy and insufficient discriminatory power of traditional techniques. We report the development of a molecular technique that utilizes real-time PCR-based high-resolution melting (HRM) analysis for differentiation of the most common Nocardia species. Based on a novel fusA-tuf intergenic region sequence, Nocardia farcinica, Nocardia cyriacigeorgica and Nocardia beijingensis were clearly distinguished from one another by HRM analysis. The limit of detection of the HRM assay for purified Nocardia spp. DNA was at least 10 fg. No false positives were observed for specificity testing of 20 non-target clinical samples. In comparison to established matrix-assisted laser desorption/ionization-time of flight MS, the HRM assay improved the identification of N. beijingensis. Additionally, all the products of PCR were verified by direct sequencing. In conclusion, the developed molecular assay allows simultaneous detection and differentiation of N. farcinica, N. cyriacigeorgica and N. beijingensis with high sensitivity and specificity.

Disseminated Nocardia beijingensis Masquerading as Pulmonary Tuberculosis in a Patient With Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome

Case of disseminated Nocardia beijingensis, initially diagnosed and treated by health department as tuberculosis, presented with worsening symptoms and new lesions. Adjustment to antinocardial treatment resulted in significant clinical and radiographic improvement. Maintain a high index of suspicion for Nocardia in patients diagnosed with tuberculosis with worsening lesions despite therapy.

A clinical case report of brain abscess caused by Nocardia brasiliensis in a non-immunocompromised patient and a relevant literature review

Background

Brain abscess due to the Nocardia genus is rare and usually found in immunocompromised patients. The most common subtype implicated is Nocardia farcinica while brain abscess due to Nocardia brasiliensis is comparatively rare. Diagnosis of brain abscess is based mainly on bacteriological culture from pus collected at the site of infection, and brain imaging. Stereotaxic aspiration or surgical resection combined with adequate duration of treatment with antibiotics to which the bacteria are sensitive represent effective treatment strategies.

Case presentation

We report a rare case of brain abscess caused by Nocardia brasiliensis in a non-immunocompromised patient. He admitted to our hospital twice with a headache. Stereotaxic aspiration was performed at the patient’s first appointment at the hospital, and a craniotomy was used to excise the lesion during subsequent abscess recurrence.

Conclusion

Early diagnosis, reasonable surgical intervention, and adequate duration of treatment with effective antibiotics are critical for treating brain abscess.

Pulmonary Infections Caused by Emerging Pathogenic Species of Nocardia

Pulmonary infections are the most common clinical manifestations of Nocardia species. There is an increase in cases of nocardial infections occurring worldwide attributable to the increase in the immunosuppressed population. The availability of molecular methods has aided the detection of more number of cases as well as unusual species. Still, it remains one of the most underdiagnosed pathogens. Recognition of drug resistance in this organism has now mandated early and precise identification with speciation for effective treatment and management. Nocardial species identity can predict antimicrobial susceptibility and guide clinical management. Here, we report two cases of pulmonary nocardiosis caused by unusual species of Nocardia, namely, N. cyriacigeorgica and N. beijingensis identified by 16S rRNA gene-based sequencing. These cases are being reported for their rarity.

Immunocompetent patient with a brain abscess caused by Nocardia beijingensis in Latin America: A case report

RATIONALE

Nocardia species are not commonly referred as primary infectious entities but rather as opportunistic pathogens. Infectious cases of Nocardia spp. in immunocompetent individuals are rare.

PATIENT CONCERNS

An immunocompetent 58-year-old patient presented with recurrent headaches.

DIAGNOSIS

A brain abscess was found and surgically drained. Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry and heat shock protein 65/16S-23S rRNA gene intergenic spacer genotyping from the sample revealed the etiological agent as Nocardia beijingensis.

INTERVENTIONS

Meropenem/amikacin/Trimethoprim-sulfamethoxazole were administered.

OUTCOMES

The infection persisted leading to the patient's death.

LESSONS

Here we present the first case of N. beijingensis infection of the central nervous system in an immunocompetent patient from Latin America. Further inquiry is needed to establish whether this species is more virulent than other Nocardia isolates.

What, where and why: exploring fluorodeoxyglucose-PET's ability to localise and differentiate infection from cancer

PURPOSE OF REVIEW

To review the utility of FDG-PET imaging in detecting the cause of fever and infection in patients with cancer.

RECENT FINDINGS

FDG-PET has been shown to have high sensitivity and accuracy for causes of neutropenic fever, leading to higher diagnostic certainty in this group. Recent advances in pathogen-specific labelling in PET to identify Aspergillus spp. and Yersinia spp. infections in mice, as well as differentiating between Gram-positive, Gram-negative and mycobacterial infections are promising.

SUMMARY

Patients with cancer are vulnerable to infection and fever, and the causes of these are frequently unclear using conventional diagnostic methods leading to high morbidity and mortality, length of stay and costs of care. FDG-PET/CT, with its unique complementary functional and anatomical information as well as its whole-body imaging capability, has demonstrated use in detecting occult infection in immunocompromised patients, including invasive fungal and occult bacterial infections, as well as defining extent of infection. By demonstrating disease resolution following treatment and allowing earlier cessation of therapy, FDG-PET acts as a key tool for antimicrobial and antifungal stewardship. Limitations include at times poor differentiation between infection, malignancy and sterile inflammation, however, exciting new technologies specific to infectious pathogens may help alleviate that issue. Further prospective randomised research is needed to explore these benefits in a nonbiased fashion.

Nocardia beijingensis brain abscesses in an HIV-infected individual

We describe a case of a 50-year-old Hispanic man diagnosed with HIV/AIDS who presented with a generalized tonic clonic seizure and ring enhancing cerebral lesions on imaging. He was initially treated for CNS toxoplasmosis but presented to the hospital with another tonic clonic seizure despite prescribed therapy. Brain biopsy was performed which revealed Nocardia beijingensis. He was treated with intravenous meropenem and trimethoprim/sulfamethoxazole for six weeks followed by long term oral trimethoprim/sulfamethoxazole with radiographic and clinical improvement.

Pulmonary Nocardia beijingensis infection associated with the use of alemtuzumab in a patient with multiple sclerosis

Nocardia is a Gram-positive aerobic pathogen that usually affects immunocompromised patients. We report a case of pulmonary infection caused by a rare Nocardia species, Nocardia beijingensis, in a 50-year-old woman who had received alemtuzumab for the treatment of her multiple sclerosis. The invasive pulmonary infection was successfully treated with meropenem.

Second report of a Nocardia beijingensis infection in the United States: nodular scleritis with in vitro imipenem resistance

We describe the case of a 52-year-old woman with scleritis caused by an imipenem-resistant strain of Nocardia beijingensis. The patient presented with pain, redness, and nodules on the sclera of 8 weeks' duration. A Gram stain from a nodule on the superonasal aspect of the globe was initially negative. After empiric treatment for an autoimmune etiology, cytopathology confirmed filamentous bacteria. A presumptive diagnosis of Nocardia scleritis was made, and medical management was based on a literature review on treatments for Nocardia infections. Cultures returned confirming Nocardia beijingensis. Antibiotic sensitivity testing confirmed the correct initial management. The patient's scleritis resolved with a good visual outcome.

Endobronchial Enigma: A Clinically Rare Presentation of Nocardia beijingensis in an Immunocompetent Patient

Nocardiosis is an opportunistic infection caused by the Gram-positive weakly acid-fast, filamentous aerobic Actinomycetes. The lungs are the primary site of infection mainly affecting immunocompromised patients. In rare circumstances even immunocompetent hosts may also develop infection. Diagnosis of pulmonary nocardiosis is usually delayed due to nonspecific clinical and radiological presentations which mimic fungal, tuberculous, or neoplastic processes. The present report describes a rare bronchoscopic presentation of an endobronchial nocardial mass in a 55-year-old immunocompetent woman without underlying lung disease. The patient exhibited signs and symptoms of unresolving community-acquired pneumonia with a computed tomography (CT) scan that showed a space-occupying lesion and enlarged paratracheal lymph node. This patient represents the unusual presentation of pulmonary Nocardia beijingensis as an endobronchial mass. Pathology obtained during bronchoscopy demonstrated polymerase chain reaction (PCR) confirmation of nocardiosis. Symptoms and clinical findings improved with antibiotic treatment. This patient emphasizes the challenge in making the diagnosis of pulmonary nocardiosis, especially in a low risk host. A literature review presents the difficulties and pitfalls in the clinical assessment of such an individual.