3. Pneumocystis jirovect (formerly known as P. carinii), an organism once considered to be a protozoan parasite, causes disease in the immunocompromised host. It cannot be grown in artificial media, and diagnosis is based on the clinical presentation (signs and symptoms), radiography (x-rays), and histological examination of affected tissues (the lower respiratory tract).
a. What methods of direct observation can best be used to demonstrate the presence of the organisms in host tissues? (Chapter Objective 13)
b. Describe the microscopic appearance of the organisms in tissue specimens. (Chapter Objective 4)

Question

Accepted Answer

∻1 Answer∻ ⚹ The best methods for directly observing Pneumocystis jirovecii in host tissues are immunofluorescence staining and Gomori methenamine silver (GMS) staining. ⚹ ∻Solution∻ ‖ a ⋮ Immunofluorescence staining: This technique uses antibodies tagged with fluorescent dyes that bind specifically to Pneumocystis jirovecii, allowing for visualization under a fluorescence microscope. ‖ ‖ b ⋮ Gomori methenamine silver (GMS) staining: This method stains the fungal cell walls of Pneumocystis jirovecii, making them visible as dark structures against a lighter background in microscopic examination. ‖ ∻Key Concept∻ ⚹ Direct observation of Pneumocystis jirovecii ⚹ ∻Explanation∻ ⚹ Immunofluorescence and GMS staining are reliable methods for the visualization of Pneumocystis jirovecii in tissue specimens. ⚹ ∻2 Answer∻ ⚹ Microscopically, Pneumocystis jirovecii appears as round or cup-shaped cysts that may contain intracystic bodies. ⚹ ∻Solution∻ ‖ a ⋮ Cysts: Pneumocystis jirovecii organisms are typically observed as cysts that are 5-8 micrometers in diameter. ‖ ‖ b ⋮ Intracystic bodies: These cysts may contain one or more dot-like intracystic bodies, which are the remnants of the organism's nuclei. ‖ ∻Key Concept∻ ⚹ Microscopic appearance of Pneumocystis jirovecii ⚹ ∻Explanation∻ ⚹ The organism is identified by its unique cystic form with intracystic bodies when viewed under a microscope after appropriate staining. ⚹◊What are the characteristics of Pneumocystis jirovecii that make it difficult to grow in artificial media?⍭ Generate me a similar question◊

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