Diebel: Causative Microorganisms of LRT Infections

Question 1

How many RNA segments do influenza A and B have vs. C?

Answer 1

And B- 8

C- 7

Question 2

How are influenza C infections different in terms of sxs?

Answer 2

Much less virulent than A and B and many infections are ASYMPTOMATIC

Question 3

Which influenza viruses have NO antigenic shifts?

Answer 3

B and C ( no animal reservoir)

Question 4

Which influenza viruses are unresponsive to amantadine or rimantadine?

Answer 4

B and C

Question 5

Which influenzas go through antigenic drift?

Answer 5

ALL

Question 6

Which influenza exhibits antigenic shift and drift?

Answer 6

Type A

Question 7

What is the clinical presentation of influenza?

Answer 7

Common cold and flu that can lead to

SECONDARY bacterial pneumonia

Question 8

Describe the pathology of the influenza virus.

Answer 8

Aersols> infects the larynx mucosa>
Viral HA protein contacts SIALIC ACID on cell surfaces>
endocytosis>
NA cleaves HA bound to sialic acid>
viral spread

Question 9

How does influenza cuase damage?

Answer 9

Viral replication in host cells>
death of host cell>
tissue damage/ disease

IR produces IL-1 and IFN y

Question 10

How do you diagnose influenza?

Answer 10

pt sxs

Question 11

How do you confirm influenza?

Answer 11

Rapid antigen test on nasophyrngeal swab

Culture swab to detect HA type and RBC agglutination test

Question 12

What vaccines are available for influenza?

Answer 12

Inactivated type A and B virus HA and NA ags

Question 13

What is the clinical presentation of bordatella pertussis?

Answer 13

Whooping cough

Question 14

What is the pathogenesis of pertussis?

Answer 14

Airborne transmission>
adheres to CILIA of RT via FHA>
release of toxins>
disease

Question 15

What is the pertussis toxin?

Answer 15

AB toxin>
inactivates Gi proteins>
increase in cAMP>
increase in lymphoctye numbers
impairs phagocytosis

Question 16

What is tracheal cytotoxin?

Answer 16

Kills epithelial cells and impairs mucous clearance

Question 17

What are the three stages of whooping cough?

Answer 17

1. Catarrhal (1-2 weeks)
2. Paroxysmal ( 3rd week to 2 mos)
3. Recovery (2-3rd month)

Question 18

What sxs are associated w/ the catarrhal stage?

Answer 18

flulike sxs

highly contagious

Question 19

What sxs are associated with the paroxysmal stage?

Answer 19

Coughing bouts w/ whooping inspiration

Question 20

What characterizes the recovery stage?

Answer 20

coughing subsides

Question 21

Gram - coccobacillia

Bordet gengou medium

Answer 21

Bordatella pertussis

Question 22

How do you prevent whooping cough?

Answer 22

DTaP

Question 23

How do you tx whooping cough?

Answer 23

Erythromycin for STAGE 1 only

Question 24

What can strep. agalactiae cause?

Answer 24

Neonatal pneumonia a day after birth

Question 25

How does strep. agalactiae colonize?

Answer 25

Carried in the maternal GI tract> obstetric complication> colonization of neonate

Question 26

Neonatal pneumonia caused by... Gram + Beta hemolytic Bacitractin resistant

Answer 26

strep. agalactiae

Question 27

How do you treat strep. agalactiae?

Answer 27

Penicillin G

Question 28

What microorganism most commonly affects young people that live in close quarters?

Answer 28

Mycoplasma pneumoniae

Question 29

``` What is the microorganism: No cell wall Marked pleomorphism Resistant to Beta lactam antibiotics NO gram stain ```

Answer 29

Mycoplasma pneumoniae

Question 30

What microorg causes tracheobronchitis and atypical pneumonia?

Answer 30

Mycoplasma pneumoniae

Question 31

This bacteria adheres to the respiratory epithelium, inhibits ciliary motion and destroys mucosa. B cell response to the infection causes IgM cold agglutinatinins.

Answer 31

Mycoplasma pneumoniae

Question 32

How do you treat Mycoplasma pneumoniae?

Answer 32

Erythromyacin | Tetracycline

Question 33

Chlamydia pneumoniae (TWAR) most commonly infects what population?

Answer 33

Young adults

Question 34

How does TWAR usually present?

Answer 34

Atypical pneumonia

Question 35

What is the pathogenesis of TWAR?

Answer 35

``` Obligate intracellular parasite> enters URT> phagocytosed by mphages> lymphocytes infiltrate> pulmonary edema, necrosis and hemorrhage ```

Question 36

What is the infective form of TWAR?

Answer 36

EB

Question 37

How do you diagnose TWAR?

Answer 37

Giemsa stain to visualize INTRACYTOPLASMIC inclusions

Question 38

How do you treat TWAR?

Answer 38

Doxycyline

Question 39

What respiratory disease can s. Aureus cause?

Answer 39

Pneumonia w/ cavitations

Question 40

How does S. Aureus cause Pneumonia?

Answer 40

Bacteria colonize nasopharynx> neutrophils localize to site of infection> purulent abscess forms> Pneumonia

Question 41

How does s. aureus evade host defenses?

Answer 41

Protein A coagulase hemolysins leukocidins

Question 42

A bacteria that has gram + clusters, catalase + and coagulase + is?

Answer 42

s. aureus

Question 43

How do you treat pneumonia caused by s. aureus?

Answer 43

penicillinase resistant penicillins | vancomycin

Question 44

What is an important cause of community acquired pneumonia in elderly smokers?

Answer 44

Legionella pneumophillia

Question 45

What is the clinical presentation of legionella pneumophillia?

Answer 45

Legionnaire's disease (atypical pneumonia)

Question 46

How does legionella cause pneumonia?

Answer 46

``` Inhaled> adheres to RT via pili> phaygocytosed by alveolar mphages> mphages secrete neutrophil attractants> neutrophils arrive from microabscess> severe atypical pneumonoia ```

Question 47

Silver stain, charcoal yeast extract, and Urinary antigen are used to detect...

Answer 47

Legionella

Question 48

How do you treat legionalla pnepumophila?

Answer 48

Erythromycin

Question 49

What causes pneumocystis pneumonia?

Answer 49

Pneumocystis jirovecii

Question 50

What is the pathogenesis of PCP?

Answer 50

cyst inhaled in childhood> stays latent in lungs> mild/asymptomatic pneumonia

Question 51

How do you diagnose PCP?

Answer 51

silver stain | cysts form dark oval bodies

Question 52

How do you treat PCP?

Answer 52

TMP-SMX or pentamide

Question 53

What bacteria can cause pneumonia in immunocompromised pts and resembles TB in presentation?

Answer 53

Nocardia asteroides

Question 54

What bacteria causes a pneumonia w/ cavitations that can lead so abscesses in the kidneys and brain?

Answer 54

Nocardia asteroides

Question 55

``` What bacteria is: gram + aerobic beaded filaments w/ a filamentous growth weakly acid fast? ```

Answer 55

Nocardia asteroides

Question 56

How do you treat nocardia asteroides?

Answer 56

TMP SMX drain the surgical abscesses