Mediastinal mass and pericardial tamponade in a renal transplant recipient: A rare case of nocardia infection

Otomastoiditis Caused by Nocardia Farcinica: A Case Report and Literature Review

Nocardia farcinica usually infects people with impaired immune status and usually manifests in the lungs. Otomastoiditis caused by Nocardia infection is extremely rare, with only 4 cases reported to date. This report describes a case of otomastoid N. farcinica infection in an immunocompetent patient. The case was a 10-month-old immunocompetent infant who presented with an approximately 3-month history of right ear discharge for which treatment with various antibiotics had not resulted in significant improvement. Multiple cultures of secretions and pathologic examination failed to identify the causative organism. The patient then underwent right mastoidectomy. Finally, metagenomic next-generation sequencing identified the pathogen to be N. farcinica. The patient was infection-free at the 6-month follow-up but had developed labyrinthitis ossificans. Otomastoid Nocardia infection has characteristic clinical features, namely, formation of a large amount of granulation tissue and coexistence of bone destruction and new bone formation. Traditionally, Nocardia is challenging to diagnose. Metagenomic next-generation sequencing of lesions is helpful. Complete local debridement and free drainage are key to treatment.

Multiple nocardial abscesses secondary to anti‑neutrophil cytoplasmic antibody‑associated vasculitis in an elderly patient: A case report and literature review

A nocardial abscess is a relatively rare opportunistic infection that typically occurs after immunosuppressive treatment and is a clinical challenge. In the present study, the case of a 69-year-old patient with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, and lung and kidney involvement, was reported. The patient received systemic glucocorticoid and cyclophosphamide treatment for 6 months, after which a large encapsulated abscess appeared on magnetic resonance imaging and CT in the subcutaneous tissue of the left hip and lung, respectively, and the pus culture showed Nocardia. Orthopedic abscess incision and ultrasound-guided thoracic puncture drainage were performed, and the lesion was completely absorbed after 1 month of treatment with linezolid and compound sulfamethoxazole. Tests for ANCA were negative, and renal function and urine tests were completely normal after 1 year of follow-up. Furthermore, a literature review performed for the present study retrieved a few reports of successful treatment of multiple nocardial abscesses secondary to ANCA-associated vasculitis in elderly patients in a short period of time. Therefore, the present case report and literature review have been reported to improve awareness of this rare disease, so as to facilitate its early diagnosis and treatment.

Large mediastinal mass diagnosed as Nocardia infection by endobronchial ultrasound-guided transbronchial needle aspiration in a ceramic worker: A case report

Background

Nocardia is a ubiquitous soil saprophyte transmitted through airborne or direct cutaneous inoculation routes. Although Nocardia is more common in immunocompromised patients, Nocardia may also arise in apparently immunocompetent patients.

Case presentation

We report a rare case of Nocardia infection presenting as a large mediastinal mass in an immunocompetent ceramic worker. A 54-year-old man with no previous history of immune dysfunction, a ceramic worker by profession, was referred and admitted to our hospital because of a persistent fever for 19 days. Chest CT showed a large middle mediastinal mass. However, conventional anti-infective treatment was ineffective. Under the guidance of the Virtual bronchoscopic navigation (VBN) system, he underwent Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). The purulent exudate obtained by EBUS-TBNA was further identified as Nocardia by weak acid-fast and metagenomic next-generation sequencing (mNGS). He was subsequently treated with intravenous imipenem/amikacin, switched to intravenous imipenem and oral trimethoprim/sulfamethoxazole, and the clinical symptoms were significantly improved.

Conclusions

Even in immunocompetent patients, Nocardiosis cannot be excluded. For the public, especially soil contact workers, precautions should be taken to avoid Nocardia infection from occupational exposure. This rare case may provide a diagnosis and treatment reference for clinicians.

Effect of abnormal right heart structures on the diagnosis of pulmonary hypertension

The diagnosis of pulmonary hypertension (PH) requires a right heart catheterization (RHC) that reveals a mean pulmonary artery pressure ≥ 25 mmHg. The pulmonary artery catheter traverse the right atrium and ventricle on its way to the pulmonary artery. The presence of abnormal right heart structures, i.e. thrombus, vegetation, benign or malignant cardiac lesions, can lead to complications during this procedure. On the other hand, avoidance of RHC delays the diagnosis and treatment of PH, an approach that might be associated with worse outcomes. This paper discusses the impact of right heart lesions on the diagnosis of PH and suggests an approach on how to manage this association.

The cytopathology of Actinomyces, Nocardia, and their mimickers

Nocardia species and Actinomyces species are 2 of the most commonly diagnosed filamentous bacteria in routine cytopathology practice. These genera share many overlapping cytomorphologic features, including their thin, beaded, branching, Gram-positive, GMS-positive filamentous structures that fragment at their peripheries into bacillary- and coccoid-appearing forms. Features that help distinguish between these 2 microorganisms include the width of their filamentous structures, the angles at which they branch, and their ability or lack thereof to retain a modified acid-fast stain. In addition to cytomorphologic overlap, overlap in clinical presentation is frequent with pulmonary and mucocutaneous presentations seen in both. Differentiating between Nocardia and Actinomyces is essential because patients with these infections require different approaches to medical management. Both antibiotic susceptibilities and the need for early surgical intervention as part of the treatment plan vary greatly among these 2 groups. This review focuses on the clinical presentation, cytomorphology and staining characteristics that can be useful in identifying and distinguishing between Nocardia and Actinomyces infections, as well as their mimickers.

Nocardia Colonization: A Risk Factor for Lung Deterioration in Cystic Fibrosis Patients?

Background

Cystic fibrosis (CF) patients are predisposed to infection and colonization with different microbes. Some cause deterioration of lung functions, while others are colonizers without clear pathogenic effects. Our aim was to understand the effects of Nocardia species in sputum cultures on the course of lung disease in CF patients.

Material/Methods

A retrospective study analyzing the impact of positive Nocardia spp. in sputum of 19 CF patients over a period of 10 years, comparing them with similar status patients without Nocardia growth. Pulmonary function tests (PFTs) are used as indicators of lung disease severity and decline rate in functions per year is calculated.

Results

No significant difference in PFTs of CF patients with positive Nocardia in sputum was found in different sub-groups according to number of episodes of growth, background variables, or treatment plans. The yearly decline in PFTs was similar to that recognized in CF patients. The control group patients showed similar background data. However, a small difference was found in the rate of decline of their PFTs, which implies a possibly slower rate of progression of lung disease.

Conclusions

The prognosis of lung disease in CF patients colonized with Nocardia does not seem to differ based on the persistence of growth on cultures, different treatment plans or risk factors. Apparently, Nocardia does not cause a deterioration of lung functions with time. However, it may show a trend to faster decline in PFTs compared to similar status CF patients without isolation of this microorganism in their sputum.