A rare case of pulmonary nocardiosis comorbid with Sjogren's syndrome

Mild Pulmonary Nocardiosis Caused by Nocardia terpenica in an Immunocompetent Patient

A 53-year-old immunocompetent man was admitted to our hospital because of paroxysmal cough with a low fever for more than 5 months. On admission, chest computed tomography showed multiple plaques and nodules, some with small central cavities, in both lungs and cystic and columnar bronchiectasis of the right middle bronchus. Treatment with various antibiotics was ineffective. Metagenomic next-generation sequencing of the bronchoalveolar lavage fluid showed Nocardia terpenica, and this organism was cultured from bronchoalveolar lavage fluid, resulting in a diagnosis of pulmonary nocardiosis. After administration of trimethoprim-sulfamethoxazole for 5 weeks, chest computed tomography showed a significant reduction in the lung lesions that had been detected on admission. Immunosuppressed patients are particularly prone to nocardiosis infection, which is usually severe. N. terpenica has rarely been detected in clinical samples, and its characteristics require further study with the accumulation of more clinical cases.

Molecular detection of Nocardia: development and application of a real-time PCR assay in sputum and bronchoalveolar lavage fluid samples

The diagnosis of pulmonary nocardiosis remains challenging. Rapid detection of Nocardia is of primary importance for early diagnosis and precise treatment of nocardiosis. In this study, our objective was to develop and validate a new TaqMan real-time PCR (qPCR) assay for rapidly detecting Nocardia spp. in respiratory samples. Based on published sequence data, primers in a conserved region of the 16S rRNA gene and a probe within that region that was specific for Nocardia were designed. The distinction effect of the qPCR assay was assessed between Nocardia and other respiratory-associated bacteria. Furthermore, the specificity and sensitivity of the assay were evaluated in respiratory clinical samples (n = 205), compared to the results of 16S rRNA gene amplicon sequencing and clinical diagnosis. The qPCR assay exhibited high specificity, sensitivity, repeatability, and reproducibility. The limit of detection of standard plasmid DNA was 3 × 10² copies/mL. Additionally, the qPCR assay was applied to the direct detection of 205 clinical respiratory samples. The specificity and sensitivity of the qPCR were all 100% compared to 16S rRNA gene amplicon sequencing, as well as 98.4% and 100% compared to clinical diagnosis respectively. The qPCR yielded results within 3 h of sample processing, compared to several days for culture, significantly reducing turnaround time. The results suggest that the new qPCR assay developed in this study provides reliable and rapid detection of Nocardia spp. in the respiratory tracts and is expected to reduce the time required for diagnosing and treating nocardiosis.

Nocardia cyriacigeorgica infection in a patient with repeated fever and CD4+ T cell deficiency: A case report

BACKGROUND

Nocardia pneumonia shares similar imaging and clinical features with pulmonary tuberculosis and lung neoplasms, but the treatment and anti-infective medication are completely different. Here, we report a case of pulmonary nocardiosis caused by Nocardia cyriacigeorgica (N. cyriacigeorgica), which was misdiagnosed as community-acquired pneumonia (CAP) with repeated fever.

CASE SUMMARY

A 55-year-old female was diagnosed with community-acquired pneumonia in the local hospital because of repeated fever and chest pain for two months. After the anti-infection treatment failed in the local hospital, the patient came to our hospital for further treatment. Enhanced computed tomography showed multiple patchy, nodular and strip-shaped high-density shadows in both lungs. A routine haematological examination was performed and showed abnormalities in CD19⁺ B cells and CD4⁺ T cells. Positive acid-fast bifurcating filaments and branching gram-positive rods were observed in the bronchoalveolar lavage fluid of the patient under an oil microscope, which was identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry as N. cyriacigeorgica. The patient's condition quickly improved after taking 0.96 g compound sulfamethoxazole tablets three times a day.

CONCLUSION

The antibiotic treatment of Nocardia pneumonia is different from that of common CAP. Attention should be given to the pathogenic examination results of patients with recurrent fever. Nocardia pneumonia is an opportunistic infection. Patients with CD4⁺ T-cell deficiency should be aware of Nocardia infection.

Pacemaker Associated Aspergillus fumigatus Endocarditis: A Case Report

Aspergillus endocarditis (AE) is a highly fatal infection that can occur in heart valve replacement, pacemaker implantation and other heart surgeries, and early recognition and sufficient diagnosis are challenging. Here, we report the case of a 68-year-old male with a history of dilated cardiomyopathy and pacemaker implantation who had a repeated fever with failed antibacterial treatment and sterile blood culture. He developed endocarditis, and the culture and biopsy of vegetation tissue showed the abundant presence of septate hyphae, which was subsequently identified as Aspergillus fumigatus by internal transcribed spacer (ITS) sequencing. Although the patient had serious side effects from voriconazole, he had a good prognosis following surgery and prolonged caspofungin antifungal therapy of 42 consecutive days. We discuss the diagnosis and treatment strategy of AE, and recommend galactomannan assays and next-generation sequencing for a timely diagnosis. Early surgical intervention combined with prompt antifungal therapy appears significant for survival.

A Rare Case of a Subcutaneous Abscess Caused by Nocardia cyriacigeorgica in an Immunocompetent Patient

Background

Nocardia cyriacigeorgica, which mainly causes pleuropulmonary and disseminated nocardiosis, has been proved to be one of the most common opportunistic pathogens in patients with immunodeficiency, but the cases that cause subcutaneous abscesses in normal individuals are rare and should be paid attention to.

Methods

The clinical data of a patient with cutaneous nocardiosis caused by Nocardia cyriacigeorgica in Zhejiang Provincial People's Hospital were retrospectively analyzed, including clinical manifestations, laboratory examinations, imaging examinations, medication and prognosis.

Results

Magnetic resonance imaging (MRI) showed that there was a 26 mm × 73 mm abscess under the skin. The pus in the abscess was green. Gram staining showed positive branched rod-shaped and undivided hyphae. After culture, small wrinkle dry white small colonies were observed, and it was identified as Nocardia cyriacigeorgica by MALDI-TOF MS.

Conclusion

We report the first case of a subcutaneous abscess caused by Nocardia cyriacigeorgica in an immunocompetent patient. Compared with cutaneous nocardiosis of which approximately 80% caused by Nocardia brasiliensis invasion, infection of Nocardia cyriacigeorgica is more insidious and latent, the features of the lesions are also unique. For this Nocardia cyriacigeorgica clinical isolate, the tested antibacterial drugs are generally sensitive and have an ideal prognosis after treatment with linezolid and timely debridement.

A rare case of pulmonary nocardiosis comorbid with Sjogren's syndrome

Background

Nocardia is an opportunistic pathogen, which occurs in patients with autoimmune diseases and immune dysfunction, and can cause bacteremia and other life‐threatening complications. The clinical manifestations of Nocardia pneumonia are similar to tuberculous and other clinical common bacterial pneumonia, but its antibacterial treatments are different and detection methods are unique, which may lead patients to suffer for many years due to clinical misdiagnosis and missed diagnosis.

Methods

Imaging and laboratory examinations were performed for preliminary diagnosis, and next‐generation sequencing was used to identify the exact species type of Nocardia in the bronchoalveolar lavage fluid (BALF) of the patient.

Results

Imaging and laboratory parameters preliminarily implied that the patient was infected with Nocardia with Sjogren's syndrome (SS), and NGS showed that the strain was N. terpenica.

Conclusions

Accurate etiological diagnosis and corresponding antibiotics are key to improve the prognosis of pulmonary nocardiosis in this case. Nocardia pneumonia is rare in clinical practice; it is of great medical significance to improve the understanding of pulmonary nocardiosis.