Lecture 53 - Bacterial Diseases of the CNS

Question 1

A good way to distinguish between bacterial meningitis and viral meningitis is by looking at the Cell Count, Cell Type, Glucose level, Protein level, and Lactate level in the CSF. How do these values compare between bacterial and viral meningitis?

Answer 1

Cell Count –> in the thousands for BACTERIAL, but only 50-500 for Viral.

Cell Type –> PMNs for BACTERIAL, and Lymphocytes for VIRAL

Glucose Level –> Reduced in BACTERIAL, Normal in VIRAL

Protein Level –> highly Increased in BACTERIAL (increase BBB permeability), Normal to slightly increased in VIRAL

Lactate level –> Elevated in BACTERIAL, Normal in Viral.

Question 2

Causes of bacterial Meningitis in different age groups is as follows:

N. meningitidis –> ______ and young adults

H. influenzae –> young children where _____ not used.

S. pneumoniae –> young children where _____ is used, and in adults.

All three of these bacteria have _______ that help them evade opsonizaton and host immunity in the blood –> hence why they can get into the CSF

Answer 2

Adolescents

Vaccine is not used

Vaccine is used

Capsules

Question 3

N. meningitidis is a Gram ___ diplococcus that is part of the normal flora of the ______. Which 5 capsule antigens are associated with disease?

Answer 3

Gram -

Nasopharynx

A, B, C, y, W135

Question 4

N. meningitidis virulence factors include its capsule, a secratory _____ protease which promotes adhesion, Pili which promote adhesion, and _____________ (LOS) that is highly endotoxic

Answer 4

IgA protease

Lipooligosaccharide

Question 5

N. meningitidis can cause symptoms on the skin, including ____ rash and Purpura. It can also cause massive hemorrhage and necrosis of the andrenal glands, called ________-Friderichsen syndrome. Common sequelae post N. meningitidis infection include ______ loss and mental retardation.

Answer 5

Petichial rash and Purpura

Waterhouse-Friderichsen syndrome

Hearing loss and mental retardation

Question 6

N. meningitidis infection can be diagnosed by gram staining a sample of the patient’s CSF, culturing the sample on _____ agar with 5% CO2, testing for the presence of ______ (N. meningitidis is positive for it), and a fermentation test to distinguish between meningitidis and gonorrheae (which one can ferment maltose?)

Answer 6

Chocolate agar

Oxidase

N. meningitidis can ferment Maltose

Question 7

H. influenzae is a Gram ____ coccobacillus with a _____. There are 6 capsule types (a-f) but type ____ is the virulent type. Along with meningitis, H. influenzae infection can cause ______ (croup), conjunctivitis, and septicemia. It is the second leading cause of _______ and _____ media (2nd to S. pneumoniae), and its sequelae include ____ loss and ____ _____ (just like meningitidis).

Answer 7

Gram - coccobacillus

Type B

Epiglottitis

Pneumonia

Hearing loss and Mental Retardation

Question 8

H. influenzae also grows well on ______ agar with 5% CO2, and it requires factors ___ and ___.

Answer 8

Chocolate agar

Factors X and V

Question 9

The vaccine for H. influenzae is a ____ vaccine (carb bound to protein.)

Answer 9

Conjugate

Question 10

S. pneumoniae can cause meningitis and is often seen more in which seasons?

Pneumovax and Prevnar are available vaccines. Which is given to people over 65 and which is given to children less than 2 years old?

Answer 10

Winter and spring

Pneumovax for old, Prevnar for young

Question 11

S. agalactiae is a main cause of meningitis in ______, because it is part of the normal flora in the mother’s vagina. Mothers are given _____ DURING labor as prophylaxis for their child.

Answer 11

Neonates

Penicillin

Question 12

Listeria monocytogenies is a Gram ____ bacillus that can grow at _____ temperatures. It is an important cause of meningitis in immunosuppressed populations (including neonates). The treatment is ______.

Answer 12

Gram +

Low temperatures

Penicillin