Wed Respiratory infectious disease

Question 1

two main obstacles that bacteria has to avoid in order to colonize the respiratory tract

Answer 1

overcome the mucus (would make them go to the stomach)

overcome phagocytosis

Question 2

what cells in the respiratory tract produce mucus

Answer 2

goblet cells

Question 3

common causes of bacterial sinusitis

Answer 3

s. pneumo, H. flu

Question 4

adhesion molecule that rhinoviruses use to infect the cells lining the nasal passages

Answer 4

binds to ICAM-1 on the cells

(intercellular adhesion mollecule

Question 5

details of a rhinovirus

Answer 5

Class IV RNA (ss+)
icosahedral
nonenveloped
picornavirde

Question 6

the one virus that causes common colds that is a DNA virus

Answer 6

adenovirus

Question 7

3 most common organisms in conjunctivitis

Answer 7

h. flu
Adeno
S. pneumo

Question 8

common antibiotic prescribed for bacterial sinusitis

Answer 8

amox

azith

Question 9

What bacteria is alpha hemolytic and optochin sensitive

Answer 9

strep pneumo

Question 10

what are the virulence factors associated with s. pyogenes binding to mucosal epithelial cells

what is the capsule made out of?

Answer 10

M protein, lipoteichoic acid, fibronectin-binding protein (protein F)

hyaluronic acid - prevents phagocytosis by macrophages

Question 11

group A and group B beta hemolytic strep

what antibiotic can you introduce to cultures in order to tell them apart

Answer 11

group A - strep pyo (bacitracin sensitive)

group b - strep agalactiae (bacitracin resistant)

Question 12

classification of diptheriae

Answer 12

gram +
bacilli
non spore formin
non motile

Question 13

how do you get scarlet fever

Sx?

Answer 13

certain groups of s. pyo that secrete exotoxins (ssa, speA, speC)

scarlet rash with sandpaper-like texture, strawberry tongue, cercumoral pallor

Question 14

croup

Answer 14

low fever, barklike cough, begins with common cold like Sx

Question 15

RSV

what is it

what do you see histiologically

Answer 15

respiratory syncytial virus

it is a Paramyxovirus

(PaRaMyxo - parainfluenza (croup), RSV, Measles, Mumps)

see multinucleated cells

Question 16

What does rhinovius bind to

Answer 16

icam -1

Question 17

parainfluenza virus uses what to infect

causes what disease

Answer 17

viral fusion F surface proteins for fusion and causes multinucleated giant cells in croup

Inhaled through aerosols. Infects the larynx mucosa via contact of the viral hemagglutinin (HA) envelope protein with sialic acid on cell surfaces (leads to endocytosis). The viral neurominidase (NA) envelope protein is important for cleaving HA bound to sialic acid, this permits viral spread.

Question 18

coxsackie a and b

how do you get it

Answer 18

A: Hand-foot-and-mouth disease can be seen as vesicles on the hands, feet, and mouth and typically occurs in young children. herpangia - fever, sore throat, red oropharynx vesicles

Coxsackie B virus is associated with 50% of cases of viral myocarditis. pleurodynia (pain when breathing)

fecal oral

Question 19

what are you thinkning if you see conjuctivitis with the common cold

Answer 19

adenovirus

Question 20

major virulence factors of strep pyo

Answer 20

streptokinase (converts plasminogen to plasmin  fibrinolysis), M protein (resists phagocytosis), hyaluronidase (breaks down connective tissue), DNase (breaks down DNA).

Question 21

what are you thinking if you see erysipelas

Answer 21

aka st. anthony’s fire.

caused by group A strep (strep pyo)

Question 22

what strep is bacitracin sensitive? what is resistant

Answer 22

Strep pyo - sensitive

Strep agalactiae - resistant

Question 23

biochemical factors that can aid in diagnosis of moraxella

Answer 23

hydrolyzes tributyrin, produces DNase, reduces nitrite and nitrate, does not ferment sucrose, glucose, maltose, or lactose.

Tx - augmentin (95% of cases are beta lactamase positive)

Question 24

what does diphtheria toxin do

Answer 24

it is an AB toxin that ADP rybosylates EF-2 and prevents protein synthesis in all cells

Question 25

general bacterial characteristics of diptheriae

Answer 25

gram + rod, aerobic, black colonies on potassium tellurite

may look like chinese characters under the microscope

Question 26

clinical presentation of diphteriae

Answer 26

pseudomembrane on the nasopharynx. systemic = myocarditis and polyneuritis

Question 27

what is meant by quellung +

Answer 27

bacteria has an antiphagocytic capsule

Question 28

general identifiers of strep pneumo

Answer 28

gram (+) diplococcic, α-hemolytic, catalase (-), susceptible to optochin (virdans is resistant)

Question 29

what type of H flu has a capsule

Answer 29

type B

types with capsule are more likely to go systemic.

non typable are usually just local infections

Question 30

H flu can go systemic much more easily if you don’t have this organ

Answer 30

spleen

the spleen is where opsonized bacteria get digested

Question 31

what bacteria has an IgA protease

Answer 31

H flu

Question 32

general bacterial characteristics of H flu

Answer 32

gram -, requires hemin (x factor) and NAD (V factor) on chocolate agar, + Quellung test

Question 33

respiratory syncytial virus virulence factors

Answer 33

g surface protein important for attachment to host cells. F surface protein causes infected cells to fuse (aka form syncytia)

Question 34

respiratory syncytial virus presents as

Answer 34

bronchiolitis, pneumonia in children

common cold in adults with weezing like asthma

worldwide outbreaks occur every winter

Question 35

what do you give for severe cases of RSV

Answer 35

ribavirin

Question 36

virulence factors of influenza C

Answer 36

HA (hemeagglutinin)

NA neuroaminidase