Haemophilus Species & Moraxella Catarrhalis Flashcards Preview

Term 4: Infectious Diseases > Haemophilus Species & Moraxella Catarrhalis > Flashcards

Flashcards in Haemophilus Species & Moraxella Catarrhalis Deck (29):
1

What is PAGE?

-polyacrylamide gel electrophoresis.

-used to identify outer membrane proteins (on Gm- bacteria?)

2

What portion of the H. Flu type B capsule is used in the HIB vaccine?

-polyribosyl ribitol phosphate

3

What is lipooligosaccharide (LOS)?

-present in H. influenzae

-like LPS, but much shorter side chain

-damages tissues and stimulates inflammatory response

4

H. Flu requires X factor to grow. What is X factor?

-hematin, released by lysed RBC's

-present in chocolate agar

5

How is chocolate agar made?

-by heating blood

6

H. Flu requires V factor to grow. What is V factor?

-NAD+ (nicotinamide adenine dinucleotide) 

-diffuses from RBC's -present in chocolate agar

7

How are H. parainfluenzae and H. Influenzae different in their agar growth requirements?

-parainfluenzae needs only V factor, and can grow on blood agar.

-influenzae grows only on chocolate agar and also needs X factor

8

What exotoxins are produced by H. influenzae?

-none recognized

-LOS causes inflammation and damages tissues though

9

How does HITB cause meningitis?

-directly enters CNA via veins or lymphatics

-hematogenously, settling in choroid plexus

10

What is polyribosyl phosphate?

-located in HITB capsule

-causes high level of resistance to phagocytosis

11

What is the host immune response to H. influenza type B?

-Antibody to PRP capsule opsonizes for phagocytosis & is bactericidal

-antibodies to LOS and outer membrane proteins are bactericidal to a lesser extent

12

What is the host immune response to NTHI?

-children who develop otitis initially lack IgG to outer proteins, but develop it

-some antibodies are protective

13

What is "exacerbation of COPD?"

-tracheobronchitis and pneumonia in persons with pre-existing chronic lung disease

#1 NTHI

#2 Moraxella catarrhalis

14

What two factors are present in chocolate agar that allows H. Influenzae to grow?

-X factor   (Hematin)

-V factor   (NAD+)

15

What give HITB high resistance to phagocytosis?

-polyribosyl phosphate located in its capsule

16

What indicates a highly virulent organism?

-high proportion of colonizations invade

-a high proportion of those who are infected have serious disease

17

What is puerperal fever?

-infection during birth causing fever

-from organisms in vagina

18

What diseases are caused by Haemophilus Influenza Type B (HITB)?

  1. Mningitis
  2. Acute Epiglottitis
  3. Septic Arthritis
  4. Sepsis
  5. Otitis media

19

Who is at risk for sepsis caused by HITB?

Children with abent or non-functioning spleens (sickle cell)

*HITB is encapsulated

20

How do we treat HITB?

For serious infections = 3dr generation cephalosporin

Otitis media = ampicillin/amoxicillin

21

What disease is caused by H. influenza biogroup aegyptius?

-Brazilian hemorrhagic fever (epidemic)

22

"cherry red epiglottis"

HITB epiglottitis

23

Where does HITB colonize?

Nasopharynx

24

What disease is caused by Haemophilus ducreyi?

-Chancroid

=venerial ulcers

25

How do we tell apart ulcers that are caused by H. ducreyi vs. T. pallidum (syphilis)?

Syphilis ulcers are not painful, ducreyi chancroids are 

26

Rank in order of virulence:  Moraxella, NTHI, HITB, H. parainfluenzae

HITB >> NTHI > Moraxella > H. parainfluenzae

27

What diseases are caused by Moraxella catarrhalis?

#2 exacerbation of COPD

#3 otitis media & sinusitis

28

What is the most common cause of exacerbation of COPD?

Non-typable H. influenza

29

How is H. influenza transmitted?

aerosolized