PATHOLOGY MCQ
INFECTION
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Mycobacterium tuberculosis
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Corynebacterium diphtheriae
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Staphylococcus aureus
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Escherichia coli
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Detailed explanation-1: -name does not imply that Mycobacterium are fungi; rather it describes the way that the tubercle bacillus grows on the surface of liquid media as mold-like pellicles (Gangadharam & Jenkins, 1998).
Detailed explanation-2: -Mycobacteria are immobile, slow-growing rod-shaped, gram-positive bacteria with high genomic G+C content (61-71%). Due to their special staining characteristics under the microscope, which is mediated by mycolic acid in the cell wall, they are called acid-fast. This is also the reason for the hardiness of mycobacteria.
Detailed explanation-3: -The purple rod-shaped organism is a TB bacterium. This name, meaning ‘fungus-bacteria’ refers to shape of the bacillus when it grows in a laboratory: when seen through a microscope it forms heaps of small rods with protective layers around them, and thus looks like a fungus.