URT infections

Question 1

At what point is the UTR and LTR divides

Answer 1

Vocal chords

Question 2

Microbiata of the URT is complex or sterile

Answer 2

Complex resident microbiota

Question 3

UTR is usually sterile or full of bacteria?

Answer 3

Sterile

Question 4

Infections of LTR

Answer 4

• Trachea – tracheitis
• Bronchi- bronchitis
• Bronchioles- bronchiolitis
• Alveoli- pneumonia

Question 5

Host defences of upper airway

Answer 5

• Air filtration – hairs in the nose, mucus.
• Epiglottic reflex – prevents aspirating (Swallowing the wrong way)
• Cough
• Mucociliary clearance – move mucus to reach oesophagus
• Secretory IgA

Question 6

The eppiglottic reflex prevents what

Answer 6

Aspirating, swallowing the wrong way

Question 7

Mucociliary escelator does what

Answer 7

Move mucus to reach oesophagus

Question 8

Why does a tracheotomy impair host defences

Answer 8

Bypasses mechanisms

Question 9

What does alcohol impair of the host defenses

Answer 9

Epiglottic reflex

Question 10

How do foreign bodies impact host defenses

Answer 10

impair mucus, cough, secretory IgA. Have pathogens on them. Impact mucociliary escalator.

Question 11

What type of disease can increase pathogen capture by mucus leading to defense impariement

Answer 11

CF

Question 12

What are UTRs mostly caused by

Answer 12

Viruses

Question 13

Medical term for sore throat

Answer 13

Pharyngitis

Question 14

The tonsils are a collection of what tissue

Answer 14

Lymphoid tissue

Question 15

What bacteria causes acute pharyngitis and tonsilitis

Answer 15

Group A strep and S. pyogenes

Question 16

More minor bacterial causes of acute pharyngitis and tonsilitis

Answer 16

• Mycoplasma pneumoniae
• Chlamydophila pneumoniae
• Corynebacterium diphtheriae
• Neisseria gonorrhoeae

Question 17

What is Quinsy

Answer 17

Peritonsillar abcesses in the tonsils

Question 18

What antibiotics well against streptococcal sore throats so why is it used

Answer 18

Beta-lactam (don’t produce beta lactamases)
Macrolides

Question 19

Complications of strep infections

Answer 19

Non-infectious sequelae
Post-strep glomerulonephritis
Rheumatic fever

Question 20

What is Post-streptococcus glomerulonephritis

Answer 20

• Acute inflammation of the glomeruli in the kidney (small capillaries in kidney)

Question 21

What is a consequence of Post-streptococcus glomerulonephritis:

Answer 21

• Consequence of trapped immune complexes -> hypersensitivity. Antigen produced by the bacteria forms complexes which are very large leading to blockage in capillaries leading to inflammation.

Question 22

Rheumatic fever is what type of hypersensitivity

Answer 22

Type II

Question 23

Rheumatic fever: M protein produced by what genus

Answer 23

Streptococcus

Question 24

MOA of rhuematic fever M-protein in a hypersensetivity reaction

Answer 24

* Antibodies raised against M-protein also react with cardiac tissue. M protein is a virulence factor produced by strep, it is similar to many tissues including cardiac tissue, cross-reactivity

Question 25

Symptoms of rheumatic fever

Answer 25

* Poly arthritis * Chorea: jerky movements * Erythema marginatum: red rash rings

Question 26

How are UTR infections diagnosed, clinic and lab

Answer 26

Clinic: Scoring approaches like FeverPain and Centor Diagnostic lab: Culture/Ag testing of throat swab. Serology. Tests for other organisms like Mycoplasma and Chlamydophilias spp.

Question 27

Dipetheria toxin is p------ encoded

Answer 27

Phage

Question 28

What concentration of iron does diptheria need to produce

Answer 28

Low EC iron

Question 29

MOA of diptheria toxin

Answer 29

DT binds into a clathrin coated pit which is taken in via receptor mediated endocytosis, endosome, pH lowers. Endosomal escape and so active A subunit coverts NAD to nicotinamide which fuels the ribosylation of EF-2 which tags it with ADP ribosome leading to ribosome recycling and so cell death

Question 30

What type of toxin is diptheria toxin

Answer 30

AB

Question 31

What agar to use to diagnose diptheria

Answer 31

Blood tellurite agar, selective

Question 32

Toxin detection test for dipetheria

Answer 32

Elek test, production of precipitin, reaction of toxin and antitoxin

Question 33

What bacteria causes epiglottitis

Answer 33

Haemophilus infleunzae TypeB

Question 34

Why is epiglottitis now rare in the UK

Answer 34

vaccination

Question 35

In what age group is epiglottitis seen usually

Answer 35

Young kids

Question 36

Are the ears included in the URT

Answer 36

YES

Question 37

What causes a middle ear infection

Answer 37

S.pneuomiae H. influenzae S. pyogenes

Question 38

Symptoms of middle ear infection

Answer 38

Otalgia (earache), pus

Question 39

How to treat middle ear infection

Answer 39

Myringotomy + antibiotics

Question 40

Sinusitis definition

Answer 40

Inflammation of the mucous membrane lining the paranasal sinuses

Question 41

Bacterial causes of sinusitis

Answer 41

* S. pneumoniae * H. influenzae * Moraxella catarrhalis * Staphylococci (chronic infection)  biofilm, bad if its MRSA, possible bacteriophage therapy.