Streptomyces, the largest genus in the Streptomycetaceae family and a prolific producer of antibacterial drugs, is a saprophytic soil organism that rarely causes invasive infections. Here we report a case of necrotic pneumonia caused by Streptomyces albireticuli in a 75-year-old man who presented with progressive chest tightness and dyspnea. Streptomyces albireticuli was isolated from his bronchoalveolar lavage fluid and identified through whole-genome sequencing (WGS) and phylogenetic analysis. The patient responded satisfactorily to clarithromycin therapy. The findings of this study may enhance our vigilance in identifying visceral infections caused by Streptomyces.

Acrophialophora is a saprotrophic genus of fungi found in both temperate and tropical regions. The genus is comprised of 16 species, with the subspecies A. fusispora and A. levis necessitating the most clinical concern. Acrophialophora is an opportunistic pathogen with a broad range of clinical manifestations; the fungus has been implicated in cases of fungal keratitis, lung infection, and brain abscess. Acrophialophora infection is particularly of concern for immunocompromised patients, who often present with a more severe disease course involving disseminated infection and may not exhibit typical symptoms. Early diagnosis and therapeutic intervention are critical to the successful clinical management of Acrophialophora infection. Guidelines for antifungal treatment have yet to be established, partially due to the lack of documented cases. Aggressive use of antifungal agents and long-term treatment is required, especially in immunocompromised patients and patients with systemic involvement, due to the potential for morbidity and mortality. In addition to outlining the rarity and epidemiology of the disease, this review provides an overview of the diagnosis and clinical management of Acrophialophora infection to facilitate an early diagnosis and appropriate interventions.

Cystic fibrosis (CF) lung disease is characterised by recurring bacterial infections resulting in inflammation, lung damage and ultimately respiratory failure. Pseudomonas aeruginosa is considered one of the most important lung pathogens in those with cystic fibrosis. While multiple cystic fibrosis animal models have been developed, many fail to mirror the cystic fibrosis lung disease of humans, including the colonisation by opportunistic environmental pathogens. Delivering bacteria to the lungs of animals in different forms is a way to model cystic fibrosis bacterial lung infections and disease. This review presents an overview of previous models, and factors to consider when generating a new P. aeruginosa lung infection model. The future development and application of lung infection models that more accurately reflect human cystic fibrosis lung disease has the potential to assist in understanding the pathophysiology of cystic fibrosis lung disease and for developing treatments.

BACKGROUND: Blastoschizomyces capitatus infection is a rare fungal infection; mainly occurring in immunodeficient patients, which can cause multiple organ involvement. At present, there is no clear designated treatment regimen. This case was a rare example of Blastoschizomyces capitatus lung infection in patient with normal immune function, which was effectively controlled by combined antifungal therapy.
METHODS: We report a 67-year-old male smoker, who, after cleaning a small bungalow for a long period, without any protective measures, developed cough with expectoration, fever and dyspnea. Pre-admission anti-infective medication (amoxicillin and roxithromycin) had little effect, and the patient\'s condition worsened. He had a past history of pulmonary tuberculosis with pleurisy 6 years before. Chest computed tomography (CT) showed evidence of old tuberculosis in the right upper lobe and inflammation in both lower lobes. White blood cell count was 14.51×109/L, neutrophils was 13.39×109/L and C-reactive protein (CRP) was 170 mg/L. Broad-spectrum antibiotics piperacillin sodium 4.0 g and tazobactam sodium 0.5 g q8h were administered empirically for 5 days. Blastoschizomyces capitatus infection was confirmed by next generation of macro genome sequencing (NGS) of bronchoalveolar lavage fluid and mass spectrum analysis of sputum. He was then switched to voriconazole antifungal therapy combined with aerosol inhalation of amphotericin B. His temperature normalized, expectoration and dyspnea were relieved. Total white cell count fell to 8.10×109/L, neutrophils to 5.81×109/L, and CRP to 76.8 mg/L.
CONCLUSIONS: This case demonstrates that Blastoschizomyces capitatus infection can occur in patients with normal immune function. Mass spectrometry and metagenomic NGS methods may have an advantage over traditional methods in identifying this fungal infection. In addition, the combination of voriconazole and nebulized amphotericin B can be employed as a novel regimen for treating Blastoschizomyces capitatus infection. For pulmonary infection with a history of environmental exposure, early pathogen identification and culture, and appropriate antibiotic treatment are key to optimizing outcome.

Gardnerella vaginalis is a pathogen responsible for bacterial vaginosis, which is commonly found in female vaginas and rarely causes infections outside the female genitalia. Here, we report the use of metagenomic next-generation sequencing (mNGS) to detect and confirm pulmonary infection and pleural effusion caused by G. vaginalis in a 47-year-old man. The patient\'s symptoms and imaging improved after 2 weeks of oral ornidazole, and he was cured after 3 months. Overall, the findings of this case demonstrate that mNGS is a useful tool for diagnosis of unexplained lung infections and pleural effusions. Its effectiveness in rapid and accurate etiological diagnosis and monitoring of diseases can allow detection of the etiology of difficult cases that return negative results after traditional cultures.

BACKGROUND: Primary anaplastic large cell lymphoma of the lung represents a diagnostic challenge due to diverse manifestations and non-specific radiological findings, particularly in cases that lack extra-pulmonary manifestations and lung biopsy.
METHODS: A 40-year-old woman presented with a 6-d history of fever, dry coughing, and dyspnea. Her white blood cell count was 20100/mm3 with 90% neutrophils. PaO2 was 60 mmHg and SaO2 was 90% when breathing ambient air. Chest computed tomography (CT) identified a solid nodule, 15 mm in diameter, with a poorly defined boundary in the upper right lung, and several smaller solid nodules throughout both lungs. Pulmonary artery CT and subsequent bedside X-ray showed diffuse patchy shadows throughout both lungs. Repeated cultures of blood samples and alveolar lavage failed to identify any pathogen. Due to the mismatch between clinical and imaging features, we conducted a bone marrow biopsy, and the results showed proliferation along all three lineages but no atypical or malignant cells. The patient received empirical antibacterial, antiviral, and antifungal treatments, as well as corticosteroids. The patient\'s condition deteriorated rapidly despite treatment. The patient died 6 d after hospitalization due to respiratory failure. Post-mortem lung biopsy failed to show inflammation but identified widespread infiltration of alveolar septum by anaplastic lymphoma kinase (ALK)-positive anaplastic cells.
CONCLUSIONS: ALK-positive anaplastic large cell lymphoma could present as a primary pulmonary disease without extra-pulmonary manifestations.