Pulmonary nocardiosis revisited: A case series

Unremitting Asthma as a Presentation of Pulmonary Nocardiosis: A Case Report

Severe, refractory asthma requires a combination of multiple maintenance inhalers and medications including high-dose inhaled corticosteroids and immunomodulators to achieve control of symptoms. The use of inhaled corticosteroids, however, increases the susceptibility of opportunistic bacterial infections, such as Nocardia, resulting in pulmonary nocardiosis. This case describes a 46-year-old patient with a history of severe, refractory asthma who presented with progressively worsening asthma exacerbation symptoms. She was treated with immunomodulators, high-dose inhaled corticosteroids and oral steroids, and several courses of antibiotics. CT imaging revealed bibasilar peri-bronchial thickening and tree-in-bud nodularity in the right lower lobe. Pulmonary cultures collected from bronchoscopy grew Nocardia nova complex. This was a rare case of persistent asthma exacerbation by N. nova complex bronchopulmonary infection. Broad differentials should be considered in patients with severe, refractory asthma who were previously controlled and were found to fail treatment therapies. Immunocompromised patients with chronic lung disease are at higher risk of severe infection with disseminated nocardiosis. These patients have a higher mortality and morbidity risk if early diagnosis of pulmonary nocardiosis does not occur.

Case Report: Nocardia amamiensis Infection Leading to Worsening of Chronic Obstructive Pulmonary Disease Symptoms in an Elderly Man

Nocardiosis is a rare opportunistic infection mostly affecting the lungs, brain, or skin of immunocompromised individuals. Most pulmonary nocardiosis patients present with nonspecific clinical features such as productive cough, exertional dyspnea, and fever. The disease is uncommonly suspected, especially in tuberculosis-endemic regions, and clinical diagnosis is often delayed, resulting in high mortality. Pulmonary nocardiosis in apparently immunocompetent individuals is uncommon. Here, we present the case of an elderly gentleman with a background history of poorly controlled diabetes but no history of systemic steroid use who presented with worsening symptoms of chronic obstructive pulmonary disease in the form of productive cough and dyspnea. The patient had diffuse crepitations in bilateral lung fields and an arterial oxygen saturation of 86% at admission. Sputum microscopy revealed gram-positive filamentous bacteria that could be successfully cultured and identified as Nocardia amamiensis on 16S ribosomal RNA sequencing. Contrast-enhanced computed tomography of the lungs revealed cavitary nodules and consolidation. The patient responded well to treatment with specific antibiotics based on sensitivity patterns. Because of the nonspecific clinical and radiological findings in pulmonary nocardiosis, a high index of suspicion is required, especially in tuberculosis-endemic regions.

Clinical Features, Radiological Findings, and Treatment Outcomes in Patients with Pulmonary Nocardiosis: A Retrospective Analysis

Introduction Lack of specific clinical features makes the diagnosis of pulmonary nocardiosis difficult. A high index of suspicion is required for diagnosis especially in cohorts with pre-existing risk factors. This study aimed to study the clinical and radiological characteristics and outcomes in patients with pulmonary nocardiosis. Methods This was a retrospective observational study. Data of confirmed cases with pulmonary nocardiosis were collected from a digital patient management system. Results A total of eight cases of pulmonary nocardiosis were included. The mean age of patients was 50 ± 14.3 years with a female preponderance (62.5%). The most common co-morbidity was chronic lung disease (37.5%). The common clinical feature of pulmonary nocardiosis was cough with expectoration (50%) and the mean duration of symptoms was 18 days. The common radiological (CT thorax) findings were consolidation, bronchiectasis, mediastinal lymphadenopathy, and nodularity (50% each). One patient had an extension of pulmonary disease in the chest wall. Microbiological detection of Nocardia spp. was done in sputum samples (50%) and in bronchoalveolar lavage (BAL) samples (50%). Culture was positive in two BAL samples. Intravenous empirical antibiotics in combination with oral trimethoprim-sulfamethoxazole double standard (15 mg/kg trimethoprim) were started at the time of diagnosis. Ceftriaxone and amikacin were commonly used antimicrobials. Conclusion Nocardia spp. commonly causes disease in patients with pre-existing chronic disease. A high index of suspicion is required in patients with subacute to chronic respiratory symptoms, raised inflammatory markers, and the absence of common respiratory pathogens in evaluation.

Genotypic and phenotypic prevalence of Nocardia species in Iran: First systematic review and meta-analysis of data accumulated over years 1992-2021

Background

Nocardia species belong to the aerobic actinomycetes group of bacteria which are gram-positive and partially acid-fast Bacilli. These bacteria may sometimes be associated with nosocomial infections. Nocardia diseases are not required to be reported to public health authorities in Iran. Hence, the present study was designed to determine the prevalence of human Nocardia spp. in Iran by using a systematic review and meta-analysis according to the preferred reporting items for systematic reviews and meta-Analyses statement.

Methods

The data of the prevalence of Nocardia species were collected from databases such as Embase, PubMed/MEDLINE via Ovid, Web of Science, Scopus and Google Scholar as well as national Iranian databases, including SID, Magiran. Analyses were conducted by STATA 14.0.

Results

The meta-analyses showed that the proportion of Nocardia spp. in Iranian studies varied from 1.71(1.17, 2.24) to 0.46(0.09, 0.83). N. asteroides (21% [95% CI 1.17, 2.24]), N. cyriacigeorgica (17% [95% CI 0.99, 1.77]), N. facanica (10% [95% CI 0.75, 1.00]) were considered to be common causative agents.

Conclusions

Our study presents that despite the fact that Nocardia spp. are normally are saprophytic organisms, are currently accounts as emerging pathogens due to an increase in immunocompromised patients among Iranian populations. Considering our results, the establishment of advanced diagnostic facilities for the rapid detection of Nocardia infections are required for optimal therapeutic strategies of Nocardia spp. in Iran. Our findings could help the programmatic management of the disease within the context of Nocardia control programs.

Rare isolation of Nocardia farcinica in a fatal case of disseminated nocardiosis in an immunocompetent person

Nocardia species can cause various types of infections including, pulmonary, cutaneous, disseminated & CNS diseases. Here, we report a case of disseminated nocardiosis, probably secondary to pulmonary foci, in an immunocompetent patient. Blood culture showed gram-positive bacilli, which on culture grew aerial chalky white growth showed the acid-fast, gram-positive filamentous bacteria. The culture was identified as Nocardia farcinica by MALDI-TOF. Unfortunately, the patient succumbed to the infection on the 5th day after admission.

Nocardia Infections: Ten Years Experience from a Tertiary Health Care Center in North India (2007-2016)

BACKGROUND

Nocardia species are important cause of infections in humans but are underreported due to missed diagnosis as well as misdiagnosis. Majority of the literature on these infections consists of case reports or series with few articles describing high number of cases.

OBJECTIVE

To study the epidemiology of Nocardia infections in a tertiary care center.

MATERIALS AND METHODS

This retrospective observational study was done in a tertiary care centre of North India over a period of 10 years (2007-2016). The detection of Nocardia spp. from clinical specimens was done by conventional methods viz. direct microscopy (Gram's stain, modified Ziehl -Neelsen stain [1%], KOH examination) and culture.

RESULTS

A total of 25 cases of nocardiosis were diagnosed during the study period. The mean age of the patients was 50.9 years (range 30-72 years) with a male:female ratio of 3:2. The site of disease in these patients included pulmonary (n=18), cutaneous (n=4), perinephric abscess (n=1), ocular (n=1) and bone (n=1). Risk factors associated were underlying lung disease (n=11), smoking (n=7), diabetes (n=5) and steroid therapy (n=4) in pulmonary nocardiosis, iatrogenic (n=1) and leprosy (n=1) in cutaneous nocardiosis, diabetes in perinephric abscess and cataract surgery in ocular nocardiosis. Culture was positive in 12/25 (48%) patients for Nocardia spp. Direct microscopy was positive in 22 patients. We wish to highlight that meticulous observation of KOH wet mount examination helped in clinching the diagnosis of Nocardiosis in 3 cases which were earlier missed by other methods.

CONCLUSION

Good communication with the clinician alongside a meticulous effort in the laboratory is essential for appropriate diagnosis and management of these cases.

Pulmonary nocardiosis masquerading renascence of tuberculosis in an immunocompetent host: a case report from Nepal

BACKGROUND

Pulmonary nocardiosis is an opportunistic infection in an immunocompromised patient; however, often neglected in the immunocompetent patient from the diagnosis considerations.

CASE PRESENTATIONS

We describe a case of pulmonary nocardiosis masquerading renascence of tuberculosis, in a 51-years-Nepali farmer. After a 6 month of presumed successful antitubercular therapy; the patient develops the clinical presentations and radiological features showing similarities with that of tuberculosis and malignancy. MTB complex was not detected with Xpert MTB/RIF assay and cytological examinations were negative for the malignant cells, however. The Ziehl-Neelsen staining of the broncho-alveolar-lavage revealed acid-fast, thin branching filamentous organisms suggestive Nocardia spp. Further, identifications and susceptibility pattern against recommended antibiotics were assessed as per the CLSI guidelines. The case was then, subsequently, diagnosed as pulmonary nocardiosis. Trimethoprim-sulfamethoxazole was prescribed for 12 months. The patient underwent progressive changes and no relapse was noted in a periodic follow-up.

CONCLUSIONS

This case underscores that pulmonary nocardiosis requires diagnostic considerations, regardless of a patient's immunologic status and other mimicking infections.

Pulmonary nocardiosis in Chronic Obstructive Pulmonary Disease: A new clinical challenge

Pulmonary nocardiosis (PN) is a rare but severe disease caused by Nocardia spp. Despite the traditional description as opportunistic infection, case reports and case series of pulmonary nocardiosis have recently been reported in immunocompetent patients too, in particular among people with chronic pulmonary diseases such as advanced Chronic Obstructive Pulmonary Disease (COPD). PN is characterized by non-specific symptoms and radiological findings; bacteriological culture can be difficult. For the reasons above, diagnosis of PN is challenging, sometimes resulting in a misdiagnosis of tuberculosis. We report an interesting case of PN in a 75-year-old male with COPD. He complained a 3-months history of fatigue, evening rise in body temperature, night sweats, unexplained weight loss of 5 kg, worsening dyspnea, cough and mucopurulent sputum. The chest X-ray showed multiple nodules with cavitations bilaterally in the apical and subclavian regions. Nocardia cyriacigeorgica with 100% identity was identified in three sputum samples. Since the patient has never undergone a systemic and/or inhaled steroid therapy, and has no respiratory failure and comorbidities entailing immunodepression, it is conceivable that, in this immunocompetent patient, the COPD could represent an isolated risk factor for PN. Risk factors, clinical presentations, radiographic findings, differential diagnosis and review of the literature of PN cases in COPD, pointing out the similarities and differences, are also described.