Lecture 25- upper respiratory tract 2

Question 1

bacterial vs viral conjunctivitis

Answer 1

bacterial has more pus and discharge

Question 2

what are the causative agents of bacterial conjunctivitis

Answer 2

• haemophilus influenza- gram neg rod
• streptococcus pneuoniae- pneumococcus
• Moraxella lacunata
• enterobacteria
• N. gonorrhoeae

Question 3

treatment for bacterial conjunctivitis

Answer 3

• gentamicin and ciprofloxacin eye drops

- resistant H. influenza and s. pneumoniae exist locally

Question 4

what are the most common causes of otitis media/sinusitis

Answer 4

Moraxella catarrhalis -gram neg rod

h. influenzae- gram neg rod
s. pneumoniae- causes alpha hemolysis- gram + cocci

Question 5

difference between alpha and beta hemolysis

Answer 5

alpha- doesn’t completely cause hemolysis in agar- looks green
beta- full hemolysis

Question 6

streptococcus pneumoniae

Answer 6

• normal flora except for compromised immune systems

- can cause paranasal sinusitis, middle ear infections, lobar pneumonia, meningitis

Question 7

what are the two types of chlamydia?

Answer 7

• chlamydia- causes trachomatis

- chlamydophila- causes psittaci and pneumoniae = small obligate intracellular parasite

Question 8

what forms can chlamydia come in?

Answer 8

elementary bodies- metabolically inactive, infectious -when cells lyse, the elementary bodies are released and infectious (analogous to a spore)
reticular bodies-metabolically active, NONinfecious- involved in replication and growth of the bacteria

Question 9

Chlamydia trachomatis
causes what?
how does it cause disease?
how does it gain access to host?
symptoms and what is the progression of the disease?

Answer 9

• adult and neonatal conjunctivitis, infant pneumonia
• symptoms caused by overactive and inflammatory host response and damage to tissue when the bacteria replicates
• gains access via abrasions or lacerations
• redness and swelling and eventually blindness- follicular conjunctivitis causes diffuse inflammation across the conjunctiva that leads to scarring and causes the eyelids to turn inward, then the eyelids abrade the cornea causing blindness

Question 10

adult inclusion conjunctivitis

Answer 10

• acute follicular conjunctivitis
• same like genital infections and occurs in sexually active people
• mucopurulent discharge, keratitis, corneal infiltrates
• caused by trachomitis

Question 11

neonatal conjunctivitis

Answer 11

• exposed at birth
• 5-12 days after birth eyes swell and if left untreated after 1 year can lead to scarring
• at risk for infant pneumonia
• caused by trachomitis

Question 12

infant pneumonia

Answer 12

2-3 wks after birth

causes bronchitis with a dry cough and afebrile

Question 13

chlamydophila pneumoniae

Answer 13

• important cause of pneumonia, bronchitis and sinusitis
• most common in adults
• most sever infections involve only 1 lobe

Question 14

what is tricky about diagnosing chamydophila pneumoniae

Answer 14

it cant readily be distringuished from respiratory viruses and mycoplasma neumoniae and legionella pneumophila

Question 15

besides pneumonia, bronchitis, and sinusitis, what is chlamydophila pneumoniae thought to be associated with

Answer 15

atherosclerosis

Question 16

Chlamydophila psittaci
what's it associated with
treatment
-how does the bacteria spread?
-symptoms

Answer 16

-associated with parrots-infection via respiratory tract
-treatment- macrolides (azithromycin and erythromycin), tetrocyclin or lecofloxin
-spreads via respiratory tract and and spreads via reticuloendothelial cells to the liver and spleen causing necrosis
symptoms- due to lymphatic and inflammatory response- get SOB and alveolar inflammation