Successful treatment of pulmonary nocardiosis with fluoroquinolone in bronchial asthma and bronchiectasis

Application of bronchoalveolar lavage fluid cytomorphology in diagnosing Nocardia otitidiscaviarum: a case report

BACKGROUND

Nocardiosis is a rare infectious disease, which is frequently underdiagnosed because of the distinct bacterial shape of the causative agent and its developmental history. The morphological analysis of bronchoalveolar lavage fluid can facilitate the detection of pathogenic bacteria by observing cellular-bacterial interactions.

CASE PRESENTATION

An immunocompetent 67-year-old male patient of Asian ethnicity developed a cough without apparent cause 20 days earlier. We initially discovered mycobacteria that appeared to be Nocardia in the cytomorphological examination of bronchoalveolar lavage fluid, which was later determined to be Nocardia otitidiscaviarum through metagenomic next-generation sequencing and microbiological cultures. The patient was eventually diagnosed with Nocardia pneumonitis after other testing and clinical signs were considered. After anti-infective treatment, the patient improved and was discharged.

CONCLUSION

Several diagnostic approaches were used in this case, and the importance of cell morphology as an early screening method was emphasized for suspected Nocardia infection.

Several Nocardia abcessus bronchiolitis in a patient treated with inhaled corticosteroids: a case report

Nocardiosis is a disease that mainly affects immunocompromised patients. Inhaled corticosteroids (ICS) are standard of care for asthma. This treatment can induce respiratory infections but no case of bronchiolitis nocardiosis have been described so far. A 58-year-old man, with history of controlled moderate allergic asthma, develop an increased cought in the last two years associated with dyspnea on exertion. Within two months, although ICS were increased to high doses, symptoms worsened due to a severe obstructive ventilatory disorder as revealed by pulmonary function tests (PFT). Small-scale lesions (< 10%) were found on chest computed tomography (CT). A bronchoalveolar lavage (BAL) found Nocardia abcessus. After six months of Sulfamethoxazole/Trimethoprim, PFT results improved and chest CT became completely normal. We therefore present the case of a bronchiolitis nocardiosis with several bronchial syndrome and the only immunosuppressive factor found were ICS.

A fatal case of disseminated nocardiosis due to Nocardia otitidiscaviarum resistant to trimethoprim-sulfamethoxazole: case report and literature review

Background

Disseminated nocardiosis still causes significant morbidity and mortality and is often caused by Nocardia asteroides, N. basiliensis, and N. farcinica and are often treated with trimethoprim–sulfamethoxazole (TMP–SMX). Nocardia otitidiscaviarum (N. otitidiscaviarum) rarely causes disseminated disease and resistance to TMP–SMX is even more rare.

Case presentation

A 37-year-old woman with metastatic breast cancer and right ear deafness with recent occupational gardening and manipulating soil, presented to the hospital with first time seizure and multiple skin nodules. Magnetic resonance imaging (MRI) showed ring enhancing lesions, biopsy of the skin and brain lesions grew N. otitidiscaviarum. She was empirically treated with TMP–SMX and Imipenem–Cilastatin, however, almost three weeks into therapy, susceptibility results revealed it to be resistant to both antimicrobials, she was subsequently changed to Amikacin, Linezolid, Moxifloxacin, and Doxycycline but ultimately died.

Conclusions

This case report highlights the importance of suspecting a rare Nocardia species in patients at risk with proper occupational exposure, moreover, TMP–SMX resistance should be suspected with lack of clinical response, this may have important implications on clinical practice when facing similar infections.

Detection of Nocardia by 16S Ribosomal RNA Gene PCR and Metagenomic Next-Generation Sequencing (mNGS)

In this study, the aim was to investigate the discriminatory power of molecular diagnostics based on mNGS and traditional 16S ribosomal RNA PCR among Nocardia species. A total of fourteen clinical isolates from patients with positive Nocardia cultures and clinical evidence were included between January 2017 and June 2020 in HeNan Provincial People’s Hospital. DNA extraction and 16S rRNA PCR were performed on positive cultures, and pathogens were detected by mNGS in these same samples directly. Among the 14 Nocardia isolates, four species were identified, and N. cyriacigeorgica (8 cases) is the most common species. Twelve of the 14 Nocardia spp. isolates were identified by the two methods, while two strains of N. cyriacigeorgica were not identified by mNGS. All tested isolates showed susceptibility to trimethoprim-sulfamethoxazole (SXT), amikacin and linezolid. Apart from Nocardia species, other pathogens such as Acinetobacter baumannii, Klebsiella pneumonia, Aspergillus, Enterococcus faecalis, Human herpesvirus, etc., were detected from the same clinical samples by mNGS. However, these different pathogens were considered as colonization or contamination. We found that it is essential to accurately identify species for determining antibiotic sensitivity and, consequently, choosing antibiotic treatment. 16S rRNA PCR was useful for identification of nocardial infection among species, while this technique needs the clinicians to make the pre-considerations of nocardiosis. However, mNGS may be a putative tool for rapid and accurate detection and identification of Nocardia, beneficial for applications of antimicrobial drugs and timely adjustments of medication.

Disseminated life threatening Nocardia otitidiscaviarum infection in a young female with newly diagnosed systemic lupus erythematosus, case report and review of literature

Infection due to Nocardia is reported mainly in immunocompromised patients. It usually presents as a pulmonary or disseminated disease with a predilection for the brain. Infections are a rare etiology of intracranial vascular aneurysms. Herein we report a case of disseminated Nocardia otitidiscaviarum (N. otitidiscaviarum) in a young female newly diagnosed with systemic lupus erythematosus (SLE) complicated by the development of an infectious intracranial aneurysm. To the best of our knowledge this is the fourth case of nocardial infection-related intracranial aneurysm and the second case of N. otitidiscaviarum infection to be reported in a patient with systemic lupus erythematosus. Features of previously reported N. otitidiscaviarum related intracranial aneurysm are reviewed.

Nocardia lung abscess in an immunocompetent adolescent

The authors report a case of a lung abscess caused by Nocardia sp. in a previously healthy adolescent. A 17-year-old young man presented with tonsillitis that did not respond to β-lactamic antibiotic, dyspnoea and thoracic pain. The X-ray revealed a cavitation in the right pulmonary upper lobe. He was admitted and completed a 14-day empirical antimicrobial therapy for a pulmonar abscess, although no clinical recovery was observed. He then underwent pulmonary biopsy of the lesion and PCR analysis of the collected pulmonary tissue, which revealed the presence of Nocardia This case emphasises the importance of considering nocardiosis in the differential diagnosis of a lung abscess, particularly if no response to empirical therapy is obtained.

Relationship between the duration of trimethoprim/sulfamethoxazole treatment and the clinical outcome of pulmonary nocardiosis

BACKGROUND

Despite treatment, pulmonary nocardiosis, which is a rare opportunistic disease caused by Nocardia species, has poor clinical outcomes including recurrence and death. Currently, the treatment regimen and duration for pulmonary nocardiosis are not fully understood. The present study aimed to clarify the factors related to the clinical outcome of pulmonary nocardiosis.

METHODS

The medical records of 24 patients with pulmonary nocardiosis were retrospectively reviewed. The patients were divided into two groups based on the outcomes within 2 years: patients with controlled disease (n = 14) and patients who developed recurrence or died (n = 10).

RESULTS

Nocardia was identified by 16S ribosomal RNA sequencing in 17 patients (70.8%) and by conventional biochemical test in five patients (20.8%). The patients' characteristics, clinical findings, radiological features, and treatment history were not different between the two groups. Compared with patients who developed recurrence or died, those with controlled disease had significantly longer total duration of treatment with antibiotics, especially trimethoprim/sulfamethoxazole (67.5 ± 111.6 days vs. 9.0 ± 6.5 days; p = 0.01). Pancytopenia was the most frequent adverse effect of trimethoprim/sulfamethoxazole.

CONCLUSIONS

Longer duration of trimethoprim/sulfamethoxazole treatment was significantly associated with better outcomes of pulmonary nocardiosis. In such cases, antibiotics, especially trimethoprim/sulfamethoxazole, should be administered for more than 3 months.

Successful treatment of pulmonary nocardiosis with fluoroquinolone in bronchial asthma and bronchiectasis

A 72‐year‐old Japanese woman was admitted at Saga University Hospital for fever, malaise, and productive cough. Six years ago, she had been diagnosed with bronchial asthma and was treated with inhaled corticosteroids. Chest radiograph and computed tomography on admission showed infiltrates in the right middle lobe, a mass lesion in the left lower lobe, and bronchiectasis in both lower lobes. Sputum examination showed Gram‐positive rods with phagocytosis by neutrophils. These bacilli were identified as Nocardia otitidiscaviarum by 16S ribosomal RNA sequencing. Therefore, she was diagnosed with pulmonary nocardiosis and was treated with trimethoprim/sulfamethoxazole (TMP–SMX) and minocycline (MINO). However, she had to discontinue these antibiotics because of severe nausea and anorexia and instead was treated with fluoroquinolone for 6 months. There was resolution of the disease thereafter. Pulmonary nocardiosis with bronchial asthma and bronchiectasis can be successfully treated with fluoroquinolone, an alternative to TMP–SMX or MINO.