Respiratory Tract Infections 3

Question 1

Strep pyogenes will depict a pattern of ____ hemolysis on blood agar which is caused by the production of ________

Answer 1

β hemolysis; caused by the production of streptolysin S

Question 2

scraping of the pseudomembrane due to C. diphtheria will result in _____-

Answer 2

bleeding

Question 3

Group A strep (GAS) induces pus formation due to ______ production

Answer 3

leukocidin

Question 4

__________ of EF-2 will inactivate EF-2 and present protein synthesis and thus causes cell death

Answer 4

ribosylation

Question 5

“thumb sign” on X ray is indicative of _________

Answer 5

enlarged epiglottis; (most common cause is H. influenza)

Question 6

what are some clinical symptoms of someone suffering from respiratory diphtheria

Answer 6

• exudative pharyngitis, sore throat, fever
• respiratory obstruction due to pseudomembrane
• carditis and recurrent laryngeal nerve palsy

Question 7

because diphtheria is part of the normal flora, how does it acquire toxin producing genes?

Answer 7

via β prophage carrying genes for the toxin (lysogeny)

- the phage from one patient can infect the normal nontoxigenic diphtheroid of another

Question 8

what is the main virulence factor of corynebacterium diptheriae

Answer 8

diphtheria EXOtoxin (genes for the toxin is acquired via lysogenic conversion)

Question 9

thick pseudomembrane developing over the pharynx causing respiratory obstruction is a feature of what pathogen

Answer 9

Cornybacterium diptheriae

Question 10

what is the use of the Elek test?

Answer 10

used to test for toxigenicity; the filter paper contains antitoxin and there are two lines perpendicular to it: one that is the control ad the second is the clinical isolate with the toxin

Question 11

what are some bacterial causes of sinusitis and acute otitis media? (3)

Answer 11

• strep pneumoniae
• H. influenza
• Moraxella catarrhalis

Question 12

metachromatically staining on Loeffler’s coagulated serum is a distinguishing feature of what bacteria?

Answer 12

corynebacterium diptheriae

Question 13

streptolysin S and streptolysin O are toxins associated with ________ (bacteria)

Answer 13

Group A Strep ( Strep pyogenes)

Question 14

describe the biology of corynebacterium

Answer 14

gram POSITIVE rods, non spore forming, aerobic

Question 15

the capsule on H. influenza is composed of ______

Answer 15

PRP (polyribose ribitol phosphate)

Question 16

what is the growth requirements for H. influenza

Answer 16

• chocolate agar with factor X and factor V

Question 17

______ is the most common cause of epiglottitis

Answer 17

H. influenza

Question 18

describe the biology of H. influenza

Answer 18

it is a GRAM NEGATIVE BACTERIA

• pleomorphic
• coccobacillus
• facultative anaerobe

Question 19

describe the rash seen in scarlet fever

Answer 19

• begins on the chest and spreads to the extremities

SPARES PALMS AND SOLES

Question 20

EF (elongation factor) -2 is inactivated by the A subunit of the ________ toxin by ribosylation

Answer 20

diphtheria

Question 21

group A strep’s capsule is made of _______

Answer 21

hyaluronic acid

Question 22

club shaped, “Chinese letters” arrangement or picket fence pattern is used to describe what genus of bacteria?

Answer 22

corynebacterium

Question 23

inactivation of EF-2 is seen in the pathogenesis of what bacteria?

Answer 23

corynebacterium diptheriae

Question 24

what are some clinical syndromes associated with H. influenza?

Answer 24

• epiglottitis
• otitis media
• pneumonia
• meningitis

Question 25

Corynebacterium diphtheria is grown on _____ agar

Answer 25

tellurite agar because it has the enzyme tellurite reductase which allows it to grow on it

Question 26

what is the Quellung reaction and what is an example of a bacteria is it used for?

Answer 26

• put in the bacteria in a serum that has antibodies against its capsule. will see the bacterial swell.

used for strep pneumonia because that is one of the strep’s that couldn’t be grouped using the Lancefield method

Question 27

there is a vaccine for H influenza, specifically type ___

Answer 27

type b

Question 28

type ____ of H influenza is associated with invasive disease

Answer 28

type b

Question 29

P-2 outer membrane protein that attaches to __________ is a virulence factor for _____

Answer 29

sialic acid containing mucin oligosaccharides;

H. influenza

Question 30

______ can be heard on patients with airflow obstruction of the larger airways

Answer 30

stridor; seen in C. diphtheria patients in who the pseudomembrane blocks the airway

Question 31

Quellung reaction is used to serotype which organisms? (4)

Answer 31

• Strep pneumonia
• Klebsiella pneumoniae
• H. influenza
• Neisseria meningitides

Question 32

which bacteria as a PRP containing capsule

Answer 32

H. influenza