This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
[{'content': 'All are true regarding cryptococcal infection, except - \nSelect and explain. \nA. Occurs in immunodeficient states, B. Capsular antigen in CSF is a rapid method of detection, C. Anticapsular antibody is protective, D. Urease +ve', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Anticapsular Antibody is protective CRYPTOCOCCUS NEOFORMANS . The only pathogenic yeast . Four capsular serotypes - A, B, C and D . It has polysaccharide capsule . Most infections in immunocompromized patients are caused by serotype A. . Pigeon droppings commonly contains serotype A and D. . Eucalyptus tree contain serotype B. . It is urease positive. Mode of transmission - By inhalation of the fungus into the lung (most common) - Through skin or mucosa (some times). Laboratory diagnosis -Lumbar puncture is the single most useful diagnositc test Laboratory diagnosis Direct microscopy . Unstained wet preperations of CSF mixed with drop of India ink or nigrosine demonstrate the capsule as a clear halo Methenamine silver or periodic acid-Schiff are used for staining a tissue sample. Culture . Can be easily cultured from CSF on sabouroud's agar Serology . The most useful serological test is LPA test (Latex agglutination test for the detection of cryptococcal polysaccharide capsular antigen) . This is highly specific and sensitive; and gives better results than direct microscopy and cultures. Culture . Can be easily cultured from CSF on sabouroud's agar", 'role': 'assistant'}]