A clinical diagnosis of meningitis is confirmed with a latex agglutination test on CSF for the capsular polysaccharide of the organism. The MOST likely causative agent is?
C. neoformans occurs widely in nature, paicularly in soil contaminated with bird droppings. Human infection occurs when inhalation of the organism occurs. Lung infection is often asymptomatic but can result in pneumonia. Meningitis occurs through dissemination, paicularly in immunosuppressed patients. India ink preparations of CSF reveal a budding yeast with a wide, unstained capsule in infected persons. Also Know: C. neoformans capsule is unique among pathogenic fungi and is a complex polysaccharide polymer, the major component of which is glucuronoxylomannan (GXM). Ref: Ray C.G., Ryan K.J. (2010). Chapter 46. Cryptococcus, Histoplasma, Coccidioides, and Other Systemic Fungal Pathogens. In C.G. Ray, K.J. Ryan (Eds), Sherris Medical Microbiology, 5e.
Candida albicans
Cryptococcus neoformans
Histoplasma capsulatum
Aspergillus fumigatus