Which of the following is diagnostic for Neisseria meningitidis?
A) the presence of Gram-negative diplococci in CSF phagocytes
B) a catalase positive reaction
C) the presence of lipid A
D) the lack of lipooligosaccharide
E) the presence of white blood cells in the CSF

Question

Quizplus · Accepted Answer

The presence of Gram-negative diplococci in CSF phagocytes is diagnostic for Neisseria meningitidis. However, this finding alone is not sufficient and must be confirmed with culture and biochemical tests. Catalase positive reaction is a characteristic of most bacteria, including Neisseria meningitidis. Lipid A is a component of lipopolysaccharide and is found in the outer membrane of Gram-negative bacteria. Neisseria meningitidis does contain lipooligosaccharide, which is a modified version of lipopolysaccharide. The presence of white blood cells in the CSF is a nonspecific finding and can be seen in a variety of bacterial and viral infections as well as non-infectious conditions.

Which of the Following Is Diagnostic for Neisseria Meningitidis