Opportunistic Mycoses MCQs

Cryptococcal antigens can be detected in CSF, serum and urine by latex agglutination test. Antigen titre in CSF stays for longer duration and is directly proportional to mortality of the patients. Reference : Jagdish Chander 3/e p306, Harrison 18/e p1651,17/e p1252 Reference : Ananthnarayan and Paniker's textbook of Microbiology 12 th edition pg no. 473

Individuals at high risk for cryptococcosis include: Patients with hematologic malignancies, recipients of solid organ transplants with ongoing immunosuppressive therapy, Persons whose medical conditions necessitate glucocorticoid therapy. Patients with advanced HIV infection and CD4+T lymphocyte counts of Reference: Harrison 18/e p1650-51, 17/e p1251

Detection of Aspergillus specific galactomannan antigen in patient's sera or urine (by ELISA) Reference : Sastry 3rd edition pg. 118

Cotrimoxazole preventive therapy for preventing PCP infection (CPT), at a dose of 800 mg/160 mg PO once daily may be initiated in the following scenarios: Primary prophylaxis: It is initiated in HIV patient in any of the conditions- If CD4 count There is no role for primary prophylaxis of cryptococcal meningitis. MAC infection occurs at CD4 count Reference: Essentials of Medical Microbiology, by Apurba Sastry and Sandhya Bhat, 3rd edition, page 334

Like protozoa, Pneumocystis exists in cyst and trophozoite forms. The cysts are found in the environment, whereas in human tissues both cysts and trophozoites (containing 4-8 sporozoites) are found. Once inhaled, the cysts are carried to the lungs where they transform into the trophozoite stage. The trophozoites induce an inflammatory response, that leads to recruitment of plasma cells resulting in formation of frothy exudate filling the alveoli. Hence, this condition is also called plasma cell pneumonia. Gomori's methenamine silver (GMS) staining is the method of choice to demonstrate the cysts of P. jirovecii. The cysts resemble black colored crushed ping-pong balls, against the green background. Treatment is with Cotrimoxazole. Reference: Essentials of Medical Microbiology, by Apurba Sastry and Sandhya Bhat, 3rd edition, page 679

Negative staining: The background stains black whereas unstained bacteria stand out in contrast. It is used for the demonstration of capsules which do not take up simple stains. Example: India ink or nigrosine Capsulated bacteria: Pneumococcus (Streptococcus pneumoniae), Meningococcus (Neisseriae meningitidis), Klebsiella pneumoniae Capsulated fungus yeast: Cryptococcus neoformans Reference: Ananthanarayan and Paniker's Textbook of Microbiology 12th edition, Pg 12

Negative staining: The background stains black whereas unstained bacteria stand out in contrast. It is used for the demonstration of capsules which do not take up simple stains. Example: India ink or nigrosine Capsulated bacteria: Pneumococcus (Streptococcus pneumoniae), Meningococcus (Neisseriae meningitidis), Klebsiella pneumoniae Capulated fungus yeast: Cryptococcus neoformans Reference: Ananthanarayan and Paniker's Textbook of Microbiology 12th edition, Pg 12

The fungal infection is highly suggestive of a T cell defect. Choices A and C do not of themselves imply a deficiency in T cell function. HLA genes are autosomal, not X-linked. Reference: Ananthanarayan and Paniker's Textbook of Microbiology 10th edition Chapter 19 , Pg 187-190