Bactereial URIs

Question 1

Professional vs opportunistic infections

Answer 1

Professionals:
- infect everyone equally

Opportunistic:
- infect immunocompromised patients or as a secondary infection to healthy people

Question 2

Most common bacterial pathogens of the upper respiratory tract

Answer 2

GAS/GCS

Bordatella pertussis (whooping cough)

Haemophilus influenza (flu B)

Corynebacterium diphtheria (diptheria)

Neisseria gonorrhoeae (gonno)

Chlamydia pneumoniae

Question 3

Bacterial rhinitis

Answer 3

Pretty rare and usually occurs as a secondary infection to a post-acute viral rhinitis (common cold)

Typical pathogens include:

• GAS (more common and not-self limiting)
• GCS (usually self-limiting
• flu B
• moraxella catarrhalis

Question 4

Pharyngitis

Answer 4

Sore throat that is either viral or bacterial.

Bacterial specific sore throat:

• swollen uvula
• gray furry tongue
• white spots are present

Viral and bacterial both have
- red swollen tongue and tonsils

Question 5

GAS strep

Answer 5

Primarily includes streptococcus pyogenes
- primary pathogen in bacterial strep throat

Can cause middle ear infections

Very painful w/ pus often

Virulence factors:

• encapsulated
• disrupts gap junctions
• M protiens (inhibits complement and IgA and is the cardinal virulence factor)
• superantigens (if untreated and chronic)

Question 6

Complications of GAS infections

Answer 6

Scarlet fever

• circum-oral rash
• epidermis sandpaper rash
• strawberry tongue
• super high fever
• cervical lymphadenopathy

Rheumatic heart disease
- antibodies to the M protein in GAS are self-reactive to cardiac tissue

Post-streptococcal glomerulonephritis (PSGN)
- devolpment 1-5 wks after acute pharyngitis (GAS strep)
- deposition of immune complexes in kidneys
- hemouria and proteinuria
- hypertension
- cant pee
- oliguria
- edema
Usually self-limiting w/ proper palatine care

Question 7

Bordatella pertussis

Answer 7

Encapsulated gram- (-) coccobacilli
- works to stasis cillia in respiratory epithelium

Tests:

• Oxidase and catalase (+)
• nitrate (-)
• citrate (-)
• urea (-)

Question 8

2 stages of whooping cough

Answer 8

Catarrhal stage

• 2 weeks long
• asymptomatic but infectious

Paroxysmal stage

• 2-10 weeks long
• whoop on inhalation
• vomiting/cyanosis/convulsions
• very dangerous to kids
• treatment at this stage is not very effective

Question 9

Epiglottis

Answer 9

Dangerous since it closes the airway
- must be intubated

Caused by flu B
- vaccine is present and easy to cure as long as you catch it

Question 10

Corynebacterium diphtheria

Answer 10

Clubbed, gram (+) coryneform bacteria (look like barbells)

Secrete diphtheria toxin

• blocks elongation factor again
• causes necrotizing epithelium

Generates a grayish pseudo membrane in infections that is visible upon inspection