Diagnosing Pneumocystis jirovecii pneumonia (PJP) can be complex, particularly in cases of significant respiratory failure. The 1,3-β-D-glucan (BDG) serum assay has emerged as a promising non-invasive diagnostic tool for detecting fungal infections, including PJP. However, factors that can confound the interpretation of BDG levels by causing elevation in serum levels have been documented. Here, we present the case of 51-year-old woman with underlying autoimmune disorder, hematologic malignancy, and chronic steroid use, who was admitted for acute hypoxemic respiratory failure. Obtaining the BDG assay after the administration of intravenous immunoglobulin (IVIG) posed a diagnostic challenge, as the patient was unable to undergo bronchoscopy. This circumstance led to a debate regarding the possibility of a false-positive BDG due to IVIG use or the presence of PJP. Ultimately, the patient was empirically treated for PJP. This case underscores the importance of comprehending factors that may contaminate BDG results, particularly in immunocompromised individuals.

Rhodotorula is a genus of ubiquitous pigmented yeast found in the environment and as a commensal of human and animal microbiota. Previously considered nonpathogenic, Rhodotorula has emerged as an important cause of nosocomial and opportunistic infections in susceptible patients. While Rhodotorula spp. are common commensals in healthy individuals, the yeast may overgrow in patients with compromised immune systems causing disease. Herein, we provide a detailed presentation of a rare case involving a 79-year-old Caucasian female with a lung malignancy who developed massive cavitations in her lungs. The patient\'s lung tissue was cultured and grew an unidentified species of the genus Rhodotorula. The patient\'s health declined rapidly, and she expired due to hypoxemia. Clinicians must recognize patient groups potentially at risk for infection with Rhodotorula spp. Early identification and initiation of appropriate interventions are crucial in reducing mortality associated with this opportunistic fungal infection.

Blastomycosis is an endemic mycotic infection caused by inhalation of thermally dimorphic fungi from the genus Blastomyces. Blastomyces dermatitidis is the species most related to human infection in the USA and North America. Adult respiratory distress syndrome (ARDS) is a rare complication of blastomycosis and is associated with high mortality. Due to its rarity, evidence-based guidelines for diagnosing and treating ARDS associated with blastomycosis are scarce. In this case presentation, a 22-year-old male with a history of chronic cannabis use presented with severe respiratory symptoms, initially treated as community-acquired pneumonia. Despite antibiotic treatment, his condition deteriorated, necessitating intubation and resulting in the development of ARDS. A delayed diagnosis of pulmonary blastomycosis was confirmed through polymerase chain reaction testing. Treatment with amphotericin B and corticosteroids proved successful in addressing the fungal infection, leading to the recovery of the patient from his severe clinical condition. This case highlights the challenges associated with diagnosing and treating blastomycosis, particularly when complicated by ARDS, emphasizing the importance of considering fungal infections in the differential diagnosis of non-responsive pulmonary infections. Additionally, it suggests the potential utility of corticosteroids in severe cases and emphasizes the crucial role of early diagnosis and a combination of diagnostic modalities for the timely management of this rare and potentially life-threatening condition.

Cryptococcosis, a fungal infection primarily caused by Cryptococcus neoformans (CN), is a significant concern for immunocompromised individuals. This paper presents a case of a 51-year-old immunocompromised male who initially presented with symptoms suggestive of community-acquired pneumonia but was later diagnosed with pulmonary cryptococcosis caused by capsule-deficient CN. The patient\'s exposure to construction dust, coupled with his immunocompromised state due to immunosuppressive treatment for psoriatic arthritis, likely contributed to his susceptibility. The unique presentation of the disease, due to the absence of the characteristic thick capsule, presented a diagnostic challenge. A brief review is provided looking at the mechanism, pathogenesis, and implications of capsule deficiency in CN. The case provides an example of one of the many presentations of cryptococcosis, especially in immunocompromised individuals, and highlights the diagnostic complexities of capsule-deficient CN strains.

Histoplasmosis, a fungal infection caused by the inhalation of Histoplasma capsulatum conidia spores, has been shown to cause disseminated disease in immunocompromised individuals. Disseminated histoplasmosis manifests as multi-system involvement including pulmonary and/or neurological disease. Imaging findings, such as pulmonary focal infiltrates, cavitary nodules, mediastinal, and hilar lymphadenopathy, are common. Here, we report a rare case of disseminated histoplasmosis in a 58-year-old immunocompetent male with no occupational exposure. This patient presented with primary adrenal insufficiency, and a subsequent CT-guided biopsy of the adrenal gland was performed and revealed numerous spores containing Histoplasma capsulatum. This patient also suffered from numerous pulmonary and neurological derangements, which are likely sequelae of the disseminated fungal infection. Ultimately, the patient succumbed to their illness and died. Preventing such outcomes relies on early detection and prompt management, which are crucial in treating disseminated histoplasmosis. Increased awareness of atypical presentations can enhance patient outcomes and alleviate the impact of this severe fungal infection. This case not only underscores the importance of considering disseminated histoplasmosis in an immunocompetent patient presenting with unexplained weight loss and adrenal insufficiency but also contributes to the limited literature on disseminated histoplasmosis in immunocompetent individuals.

While the effect of gut microbiota and/or inflammation on a distant body site, including the lungs (gut-lung axis), has been well characterized, data about the influence of lung microbiota and lung inflammation on gut homeostasis (lung-gut axis) are scarce. Using a well-characterized model of pulmonary infection with the fungus Aspergillus fumigatus, we investigated alterations in the lung and gut microbiota by next-generation sequencing of the V3-V4 regions of total bacterial DNA. Pulmonary inflammation due to the fungus A. fumigatus caused bacterial dysbiosis in both lungs and gut, but with different characteristics. While increased alpha diversity and unchanged bacterial composition were noted in the lungs, dysbiosis in the gut was characterized by decreased alpha diversity indices and modified bacterial composition. The altered homeostasis in the lungs allows the immigration of new bacterial species of which 41.8% were found in the feces, indicating that some degree of bacterial migration from the gut to the lungs occurs. On the contrary, the dysbiosis occurring in the gut during pulmonary infection was a consequence of the local activity of the immune system. In addition, the alteration of gut microbiota in response to pulmonary infection depends on the bacterial composition before infection, as no changes in gut bacterial microbiota were detected in a rat strain with diverse gut bacteria. The data presented support the existence of the lung-gut axis and provide additional insight into this mechanism. IMPORTANCE Data regarding the impact of lung inflammation and lung microbiota on GIT are scarce, and the mechanisms of this interaction are still unknown. Using a well-characterized model of pulmonary infection caused by the opportunistic fungus Aspergillus fumigatus, we observed bacterial dysbiosis in both the lungs and gut that supports the existence of the lung-gut axis.

Cladosporium sphaerospermum isa radiotrophic dematiaceous fungus that can rarely cause disease in humans such as infections of the skin, eye, upper airways, and brain. To the best of our knowledge, we present the first reported case of Cladosporium sphaerospermum-induced invasive lung infection. This case presents a 51-year-old male with a medical history significant for heavy smoking and severe alcohol abuse who was admitted for acute hypoxic respiratory failure secondary to a large exudative right pleural effusion compounded by hydropneumothorax. Despite an initial positive clinical response, appropriate medical treatment, and eradication of the infection, which was confirmed by repeat negative culture studies, the patient had a complicated hospital course. It is suspected that the patient\'s medical history played a role in the acquisition of the Cladosporium sphaerospermum infection as smoking and alcohol use are known risk factors for aspiration of pathogens into the pulmonary tract. We believe it is important to bring to attention this less known organism as a potential differential diagnosis for a complicated lung infection.

Blastomycosis is an uncommon granulomatous disease caused by infection with thermally dimorphic fungi of the genus Blastomyces. Although pulmonary infections from Blastomyces dermatitidis are uncommon, it is important to understand the geographical distribution, presentation, diagnosis, and management of treating this condition. We report a case of fulminant blastomycosis after high inoculum inhalation, with involvement of the prostate on presentation, which progressed to acute respiratory distress syndrome.

Invasive pulmonary aspergillosis (IPA) is an aggressive fungal infection of the lungs characterized by tissue invasion by fungal hyphal elements. The definitive diagnosis is challenging because it relies on histopathological demonstration of fungal elements, and these days clinicians are relying more on bronchoalveolar lavage (BAL) cultures and serum biomarkers (galactomannan and beta-D-glucan). We would like to emphasize through our case the necessity to keep a high index of suspicion for IPA despite negative cultures and serum biomarkers in immunosuppressed patients and consider surgical biopsy early.

Cryptococcus is among the most common invasive fungal pathogens globally and is one of the leading causes of acquired immunodeficiency virus-related deaths. Cryptococcus neoformans and Cryptococcus gattii are the most clinically relevant species and account for most cryptococcal disease. Pulmonary manifestations can range from mild symptoms to life-threatening infection. Treatment is tailored based on the severity of pulmonary infection, the presence of disseminated or central nervous system disease, and patient immune status. Amphotericin B and flucytosine followed by fluconazole remain the standard agents for the treatment of severe cryptococcal infection.