Pulmonary cryptococcosis due to a capsule-deficient strain confused with metastatic lung cancer

A Case of Pulmonary Cryptococcosis Caused by Capsule-Deficient Cryptococcus neoformans

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.

Capsule-Deficient Cryptococcal Meningitis: A Diagnostic Conundrum

Cryptococcosis is a serious systemic mycosis. Its incidence has escalated in the past four decades. Cryptococcus neoformans causes localized or disseminated infection in immunocompromised and immunocompetent patients. The capsulated form is commonly encountered which can be diagnosed on an India ink preparation or antigen detection. However, the noncapsulated forms are very rare and require a high index of suspicion for correct diagnosis. Herein, we present a case of cryptococcal meningitis due to a noncapsulated strain in an apparently immunocompetent patient with no proven immunodeficiencies along with review of world literature. Such cases are a diagnostic challenge for the clinician as well as microbiologist.

Genotypic Diversity Is Independent of Pathogenicity in Colombian Strains of Cryptococcus neoformans and Cryptococcus gattii in Galleria mellonella

Cryptococcosis is a potentially fatal opportunistic mycosis that affects the lungs and central nervous system. It has been suggested that certain strains of C. neoformans/C. gattii may have the potential to be more virulent according to the molecular type. This study aims to investigate the association between virulence in the G. mellonella model and genotypic diversity of Colombian clinical and environmental isolates of C. neoformans/C. gattii. A total of 33 clinical and 12 environmental isolates were selected according to their geographical origin and sequence types (STs). Pathogenicity was determined using the G. mellonella model, and the cell and capsular size before and after inoculation was determined. For C. neoformans, virulence in G. mellonella revealed that death occurred on average on day 6 (p < 0.05) and that ST5C, 6C, 25C and 71C were the most virulent. In C. gattii, death occurred at 7.3 days (p < 0.05), and ST47C, 58C, 75A and 106C were the most virulent. Capsular size increased for both species after passage in G. mellonella. In conclusion, the pathogenicity of Cryptococcus strains in the G. mellonella invertebrate model is independent of molecular type or pathogenicity factor, even within the same ST, but it is possible to find variable degrees of pathogenicity.

Técnicas histopatológicas no diagnóstico de criptococose por Cryptococcus deficiente de cápsula: relato de caso

Caso de criptococose por Cryptococcus deficiente de cápsula, no qual cultivo do espécime clínico e pesquisa do antígeno capsular no líquor e soro foram negativos. As técnicas histopatológicas foram: Hematoxilina-eosina, Grocott, Mucicarmim de Mayer e Fontana-Masson. Confirmou-se o diagnóstico do Cryptococcus deficiente de cápsula pela técnica de Fontana-Masson e pela imunofluorescência direta. É discutida a potencialidade das técnicas histoquímicas.

Proven pulmonary cryptococcosis due to capsule-deficient Cryptococcus neoformans does not differ clinically from proven pulmonary cryptococcosis due to capsule-intact Cr. neoformans

We compared the clinical manifestations, laboratory and radiologic findings, and outcomes of eight patients with proven pulmonary cryptococcosis (PC) caused by capsule-deficient Cryptococcus neoformans with those of six patients with PC caused by capsule-intact Cr. neoformans. The presentations and outcomes did not differ significantly between the groups.

Cryptococcus neoformans Infection in Patients With Cirrhosis, Including Liver Transplant Candidates

We reviewed the cases of patients with cirrhosis, including liver transplant candidates, at our institution in the last 3 years (n = 5) and those individually described in the literature (n = 28), to assess unique characteristics and outcome of cryptococcosis in these patients. Sixty-four percent (21/33) of the patients had no other recognized immunosuppression. Peritonitis (in 45%, 15/33 of the patients) with modest pleocytosis in the ascitic fluid, was the most common presenting feature. Median time to detection of Cryptococcus in the ascitic fluid cultures was 6 days. Overall mortality rate was 81% (26/32); death was deemed attributable to cryptococcosis in 24/26 patients who died. Evaluation of culture-negative neutrocytic ascites in febrile cirrhotic patients warrants consideration of cryptococcal peritonitis.

Prevalence of Cryptococcus neoformans in clinical specimens

Cryptococcus neoformans isolated from various clinical materials in 14 cases, was identified by (1) cultivation on Sabouraud glucose agar and CHROMagar Candida, (2) microscopic examination of Indian-ink-stained preparations and (3) determination of biochemical properties (assimilation and fermentation of saccharides, assimilation of KNO3, production of urease and phenol monooxygenase). C. neoformans was determined in five specimens from paediatric patients in the intensive care unit and in nine specimens from adult patients, most frequently from liquor at meningitis (n = 3).