A nurse is putting together a presentation on meningitis. Which of the following microorganisms has not been linked to meningitis in humans?
A. S. pneumoniae
B. H. influenzae
C. N. meningitidis
D. Cl. difficile
Correct Answer: D. Cl. difficile
Cl. difficile has not been linked to meningitis. Clostridium difficile (C. diff ) is a germ (bacteria) that causes life-threatening diarrhea. It is usually a side-effect of taking antibiotics.
Option A: Pneumococcal meningitis is caused by Streptococcus pneumoniae. The most common route of infection starts by nasopharyngeal colonization by Streptococcus pneumoniae, which must avoid mucosal entrapment and evade the host immune system after local activation.
Option B: H influenzae meningitis is caused by Haemophilus influenzae type B bacteria. It is the leading cause of bacterial meningitis in children under age 5. Haemophilus species are small oxidase-positive pleomorphic gram-negative aerobic or facultative anaerobic coccobacilli. Humans are the only known host for Haemophilus influenza.
Option C: Bacteria called Neisseria meningitidis cause meningococcal disease. About 1 in 10 people have these bacteria in the back of their nose and throat without being ill.