Respiratory Micro

Question 1

What are the 6 defenses of the respiratory system against microbes?

Answer 1

1 mucociliary lining
2 change in direction of airway 
3 mucociliary elevator
4 normal flora
5 alveolar macrophages
6 IgA mucosal secretion

Question 2

What are the pathogenic “requirements” to colonize the respiratory system?

Answer 2

1 sufficient dose
2 airborne
3 viable in air
4 tissue susceptible to infection

Question 3

What are the #1 and #2 causes of the common cold and describe their genomes?

Answer 3

1 rhinovirus: ss + RNA

2 coronavirus: ss + RNA

Question 4

What are the #1 and #2 causes of sinusitis?

Answer 4

#1 haemophilus influenza
#2 strep pneumo

Question 5

Describe the clinical course of sinusitus

Answer 5

viral cause lasts 5-7 days of sneezing, runny nose, nasal congestion, post-nasal drip, facial pressure, aural fullness, sore throat, fever; bacterial cause greater than 5-7 days with facial swelling and tooth pain

Question 6

How should you treat sinusitus?

Answer 6

viral - supportive

bacterial- amoxicillin, azithromycin

Question 7

In which age group is group A strep the most likely cause of pharyngitis and what complications would you need to look out for?

Answer 7

kids 5-15 yrs, treat w/in 9 days w/ penecillin/azithromycin to prevent glomerulonephritis and/or rheumatic fever

Question 8

What is the cause of diptheria and how do you treat it?

Answer 8

Corynebacterium diptheriae (gram + rods), antitoxin, antibiotic, vaccine

Question 9

What are the three causes of croup/laryngitis?

Answer 9

parainfluenza
influenza
RSV

Question 10

What is the most common age group for croup and what are the hallmark symptoms?

Answer 10

kids 6 mo - 3 years, inspiratory stridor, barking cough, accessory muscle breathing

Question 11

What is the most important virulence factor at work in Rhinovirus colonization and what does it do?

Answer 11

I-CAM 1 : adhesion, upregulated by host inflammatory factors

Question 12

Which respiratory pathogen’s genomes encode for the F viral fusion protein and what illnesses do they cause?

Answer 12

Parainfluenza (ss - RNA)- croup, common cold

Respiratory syncytial virus (ss - RNA) - pneumonia, bronchiolytis, common cold, croup

Question 13

How do you diagnose Corynebacterium diptheriae?

Answer 13

gram stain: gram + rod
KTeO3 agar culture –> black Te (+)
pseudomembrane with gray fibrinous exudate in pharnyx

Question 14

How does the diptheria toxin work?

Answer 14

it’s an A-B toxin that inhibits E2-F activity, preventing protein translation

Question 15

What are the 2 respiratory pathogens which have a fecal to oral transmission route and what illnesses do they cause?

Answer 15

Coxsackie A/B - common cold/Hand-Foot-Mouth/Myocarditis/pericarditis
Adenovirus- common cold/hemorrhagic cystitis/conjunctivitis/gastroenteritis

Question 16

How do you treat a Moraxella catarrhalis pneumonia or sinusitis?

Answer 16

amoxicillin-clavulanate, second or third gen. cephalosporins, TMP-SMX

Question 17

What are Moraxella’s most notable virulence factors and how would you diagnose an infection?

Answer 17

VF: pili, antigenic variation, endotoxin, capsule
Dx: gram stain (-), tributyrine hydrolysis, DNAse, nitrate reduction, no lactose reduction

Question 18

Name the 3 single stranded RNA viruses that cause the common cold

Answer 18

Rhinovirus, Coronovirus, Coxsackie A and B

Question 19

Top 5 causes of pneumonia in kids?

Answer 19

Strep pneumo (amox, cephalsporin)
mycoplasma pneumo (Erythro, Tetra)
chlamdia pneumo (Doxy)
Influenza
RSV

Question 20

What are the common causes of bronchitis?

Answer 20

Rhinovirus, Parainfluenza, Influenza, CoxSackie, Adenovirus, RSV, Mycoplasma, Chlamydia. Bacterial after 14 days

Question 21

What are the causes of pharyngitis?

Answer 21

in Kids - GAS

Adults - Viral- rhino, corona, para, influenza, adeno, RSV, EBV

Question 22

How do you treat nocardia asteroides?

Answer 22

TMP-SMX + drain abcesses

Question 23

How do you treat an HIV positive patient for Pneumonia?

Answer 23

TMP-SMX and pentamidine

Question 24

Name the respiratory pathogens which have hemagglutinin and explain how it works

Answer 24

Influenza, parainfluenza, adenovirus, bordatella pertussis, mycoplasma pneumo (cold hemagglutinin)

Question 25

Name the respiratory pathogens with IgA protease

Answer 25

Strep pneumo, Hib

Question 26

If you find inclusion bodies in a gram negative sample from a 15 year old with pneumonia, how would you treat them?

Answer 26

Doxy