Bacteria: Gram Negative Bacilli - Respiratory Tract

Question 1

List the three gram negative bacilli of the respiratory tract

Answer 1

1. Bordetella pertusis
2. Haemophilius infleunza
3. Legionella Pneumophilia

Question 2

Bordetella pertussis

Answer 2

1. gram-negative

2. bacterium

Question 3

Bordetella pertussis bacteria have f

Answer 3

ilamentous hemagglutinin, an adhesin that binds to respiratory epithelium of hosts

Question 4

The pertussis toxin of Bordetella pertussis

Answer 4

ribosylates Gi proteins, disabling them (leading to an overproduction of cAMP)

Question 5

In Pertussis cAMP is overproduced due to

Answer 5

the deactivation of inhibitory Gi proteins by the pertussis toxin of Bordetella pertussis

Question 6

Massive lymphocytosis results due to the

Answer 6

ribosylation (deactivation) of inhibitory Gi proteins by the pertussis toxin of Bordetella pertussis (which blocks signaling via the chemokine receptors of lymphocytes, disabling lymphocyte entry into lymphoid tissue)

Question 7

In Bordetella pertussis the mechanism of the adenylate cyclase toxin

Answer 7

(mimics adenylate cyclase → increase in cAMP) of Bordetella pertussis is identical to that of the edema factor protein of Bacillus anthracis

Question 8

The tracheal cytotoxin of Bordetella pertussis

Answer 8

destroys ciliated respiratory epithelial cells

Question 9

The second stage of Bordetella pertussis infection (the paroxysmal stage)

Answer 9

can last from 2-6 weeks or longer and presents with a characteristic “whooping” cough

Question 10

A Bordetella pertussis infection

Answer 10

A Bordetella pertussis infection (which consists of three stages: catarrhal, paroxysmal, convalescent) can last for months and is sometimes referred to as the “100-day” cough

Question 11

Treatment of pertussis

Answer 11

macrolides are effective against Bordetella pertussis, but are not as useful for improving symptoms once bacterial toxins are already circulating throughout the body

Question 12

Whooping cough is transmitted via

Answer 12

respiratory droplets

Question 13

The DTaP vaccine includes

Answer 13

acellular Bordetella pertussis antigens and is typically administered in childhood to prevent whooping cough

Question 14

Haemophilus influenzae

Answer 14

1. gram negative

2. coccobacilli

Question 15

______ ______ is the standard culture medium for growth of Haemophilus influenzae

Answer 15

chocolate agar

Question 16

What is required for growth of Haemophilus influenzae

Answer 16

1. factor V (nicotinamide adenine dinucleotide)

2. factor X (hematin)

Question 17

Haemophilus influenzae is transmitted via

Answer 17

respiratory droplets

Question 18

Haemophilus influenzae infection can lead to

Answer 18

1. epiglottitis
2. Otitis Media
3. meningitis

Question 19

In H. influenzae the epiglottis is often described as a

Answer 19

cherry red epiglottis

Question 20

Epiglottitis from H. influenzae presents with

Answer 20

1. dysphagia
2. drooling
3. inspiratory stridor

Question 21

Haemophilus influenzae strains with the type b capsule can cause

Answer 21

meningitis

Question 22

Meningitis caused by Haemophilus influenzae type b leads to

Answer 22

classic symptoms of headache and neck stiffness (meningismus)

Question 23

sickle cell and asplenic patients are at a higher risk of infection from

Answer 23

encapsulated bacteria, such as Haemophilus influenzae

Question 24

the Haemophilus influenzae b (Hib) vaccine should be administered to

Answer 24

infants to prevent serious infection

Question 25

the Haemophilus influenzae b (Hib) vaccine includes an

Answer 25

Hib polysaccharide antigen conjugated to diphtheria toxoid

Question 26

the Haemophilus influenzae b (Hib) vaccine is administered to infants in

Answer 26

a series of vaccinations between the ages of 2-18 months

Question 27

______ is used to treat Haemophilus influenzae type b meningitis or systemic disease

Answer 27

ceftriaxone

Question 28

_____ prophylaxis is given to close contacts of children with Haemophilus influenzae type b (Hib) infection

Answer 28

rifampin

Question 29

Legionella pneumophila bacteria stain

Answer 29

weakly gram-negative and require a silver stain for proper visualization

Question 30

What is the primary medium used to culture Legionella Pneumophilia bacteria

Answer 30

buffered charcoal yeast extract (BCYE) agar is the primary medium used to culture Legionella pneumophila bacteria

Question 31

______ and ______ are required for the growth of Legionella pneumophila bacteria

Answer 31

cysterine and iron

Question 32

Pontiac fever is an

Answer 32

acute, self-limiting respiratory disease that presents with mild flu-like symptoms

Question 33

smoking is a risk factor for

Answer 33

Legionnaires’ disease

Question 34

chest X-ray in Legionnaires’ disease often shows

Answer 34

patchy unilobar infiltrates that progress to consolidation

Question 35

patients with Legionnaires’ disease may present with

Answer 35

1. hyponatremia
2. neurological symptoms such as headache and confusion
3. diarrhea (pneumonia with diarrhea is highly suggestive of Legionnaires’ disease)

Question 36

patients with Legionnaires’ disease may develop

Answer 36

a high fever (usually > 39°C)

Question 37

Legionella pneumophila infection is diagnosed using a

Answer 37

urine antigen test

Question 38

______ are effective against Legionella pneumophila

Answer 38

1. macrolides

2. fluoroquinolones

Question 39

Legionella pneumophila bacteria are

Answer 39

1. oxidase positive
2. weakly gram negative
3. bacilli