Mycobacterium avium complex infection presenting as an endobronchial mass in a patient with acquired immune deficiency syndrome

Metatranscriptomic insights into the dengue patient blood microbiome: Enhanced microbial diversity and metabolic activity in severe patients

BACKGROUND

Dengue is the most re-emergent infection, with approximately 100 million new cases reported annually, yet no effective treatment or vaccine exists. Here, we aim to define the microbial community structure and their functional profiles in the dengue positive patients with varying disease severity.

METHODOLOGY/PRINCIPAL FINDINGS

Hospital admitted 112 dengue-positive patients blood samples were analyzed by dual RNA-sequencing to simultaneously identify the transcriptionally active microbes (TAMs), their expressed genes and associated pathways. Results highlight that patients with severe dengue exhibited increased microbial diversity and presence of opportunistic species (unique and core) which includes Bacillus cereus, Burkholderia pseudomallei, Streptococcus suis, and Serratia marcescens. The functional profile analysis revealed enriched metabolic pathways such as protein degradation, nucleotide biosynthesis, ion transport, cell shape integrity, and ATP formation in severe cases, indicating the high energy demands and adaptability of these microbes.

CONCLUSION

Our metatranscriptomic approach provides a species-level characterization of blood microbiome composition and reveals a heightened diversity of TAMs in patients with severe dengue, underscoring the need for further research into the role of blood microbiota in disease progression. Comparing the microbial signatures across the severity classes early in the disease offers unique potential for convenient and early diagnosis of dengue infection.

Pulmonary Mycobacterial Spindle Cell Pseudotumor: A Report of 3 Cases Including a Practical Approach to Histopathologic Recognition of This Unusual Entity

Mycobacterial spindle cell pseudotumor (MSP) is a rare benign spindle cell lesion containing acid-fact mycobacteria. These lesions are most commonly identified in the lymph nodes, skin, spleen, or bone marrow of immunocompromised patients and only rarely involve the lungs. We report 3 cases of pulmonary MSP, which include 2 patients who are known to be HIV-positive. The histopathological diagnosis of MSP in the lung lends itself to many challenges due to its rare incidence and its spindled tumor-like appearance. The differential diagnosis is broad and includes both benign and malignant entities. We highlight the importance of the clinical context in which these lesions typically present and the morphologic spectrum of features seen, and we offer a practical approach to the workup of pulmonary mycobacterial pseudotumor. Appropriate recognition of this entity should lead to an accurate diagnosis of a treatable benign condition despite the clinical presentation often favoring malignancy.

A novel presentation of Mycobacterium avium complex in a recipient of a lung transplant: a case report

Background

Lung transplantation remains an important potential therapeutic option for end-stage lung disease. It can improve quality of life and in some cases be a life-lengthening therapy. Despite the possible benefits, there are also many potential complications following transplantation. Here we describe a novel presentation of nontuberculous mycobacterium manifesting as an endobronchial mass developing 4 years after lung transplantation.

Case presentation

A 66-year-old African-American woman presented with progressive dyspnea, cough, and persistent wheezing of 2 months’ duration. She had a distant history of breast cancer and received bilateral lung transplantation due to end-stage pulmonary fibrosis 4 years prior to her current presentation. She denied fevers, but did endorse night sweats. She had diffuse expiratory wheezing on auscultation. Chest computed tomography imaging showed an endobronchial soft tissue lesion nearly occluding the left mainstem bronchus, which was concerning for endobronchial carcinoma. Rigid bronchoscopy demonstrated a fibrinous mass protruding into the left mainstem proximal to the anastomosis. A pathology report noted fragments of partially necrotic granulation tissue in addition to scant fragments of focally ulcerated bronchial mucosa. Both the tissue culture and bronchial wash stained positively for acid-fast bacilli and grew Mycobacterium avium complex.

Conclusions

Nontuberculous mycobacterium pulmonary disease is common post lung transplant and risk factors are related to immunosuppression and history of structural lung disease. Mycobacterium avium complex presenting as an endobronchial lesion in a patient post lung transplant is a novel presentation.

Infections causing central airway obstruction: role of bronchoscopy in diagnosis and management

Central airway obstructive infections (CAOI) are challenging medical conditions that may represent an advanced and complicated process of ongoing infections. The epidemiology of CAOI is unknown as well as the pathophysiology and the mechanism of development. This is due to sparse data in the literature that consists mainly of case reports and retrospective case series. CAOI can be caused by fungal, bacterial, parasitic and viral infections. Most patients with CAOI can be diagnosed clinically and with chest imaging, which demonstrate obstruction of the central airways. However, bronchoscopy is commonly used to confirm and obtain a specific diagnosis to guide specific therapy. In recent years, interventional pulmonology (IP) is becoming widely available and offer a minimally invasive approach for the management of central airway diseases such as cancers, benign strictures, and other conditions. Various bronchoscopic modalities are used to treat central airway obstruction (CAO), such as mechanical debulking, endobronchial laser therapy, electrocautery, argon plasma coagulation, cryotherapy, and airway stenting. In patients with CAOI, the role of therapeutic bronchoscopy is not clearly defined, but many isolated reports in the literature described bronchoscopic intervention in combination with medical therapy as the initial management approach. In this paper, we present cases of CAOI that underwent bronchoscopic intervention as part of their management. We described the infectious etiology, locations, bronchoscopic findings and bronchoscopic modalities for airway management.

Isolated Endobronchial Mycobacterium avium Disease Associated with Lobar Atelectasis in an Immunocompetent Young Adult: A Case Report and Literature Review

The prevalence of lung diseases caused by nontuberculous mycobacteria (NTM) is increasing worldwide. Unlike pulmonary tuberculosis, endobronchial NTM diseases are very rare with the majority of cases reported in patients with human immunodeficiency virus infection and acquired immune deficiency syndrome. We reported a rare case of endobronchial Mycobacterium avium disease associated with lobar atelectasis in a young immunocompetent patient and reviewed the relevant iterature.