Lecture 15 Flashcards
What is airborne transmission?
infection by droplet nuclei in dust
- 1 meter from the host
- sneezing and coughing
What bacteria are in dust particles?
- staphylococci
- streptococci
How does the normal microbiota suppress pathogens of the respiratory system?
competing for nutrients and producing inhibitory substances
Which part of the respiratory system is nearly sterile?
lower part
What is part of the upper respiratory system?
- nose
- pharynx
- middle ear
- eustachian tubes
What protects mucosal surfaces in the upper respiratory system?
- saliva
- tears
What are some examples of microbial diseases in the upper respiratory system?
- pharyngitis: sore throat
- laryngitis
- tonsillitis
- sinusitis
- epiglottitis
Which is the most life-threatening disease of the upper respiratory system?
epiglottitis
What are some examples of the common cold?
over 200 different kinds
- rhinoviruses (30-50%)
- coronavirus (10-15%)
- enterovirus D68
What are symptoms of the common cold?
- sneezing
- nasal secretion
- congestion
- no fever
What can the common cold lead to?
laryngitis and otitis media
How can the common cold be cured?
NOT with antibiotics
- cough suppressants
- antihistamines
What is streptococcal pharyngitis (strep throat) caused by?
streptococcus pyogenes
What is scarlet fever caused by?
streptococcus pyogenes produces erythrogenic toxin
- follow strep throat
What causes measles?
measles virus
What causes rubella?
rubella virus
What causes smallpox?
variola virus
- mostly systemic but can affect respiratory
What causes pertussis (whooping cough)?
bordetella pertussis
What causes influenza?
influenza virus
- start in upper respiratory and progresses
What is diphtheria caused by?
corynebacterium diphtheriae
What is chicken pox caused by?
varicella-zoster virus
- can also affect lower respiratory
What causes shingles?
reactivation of varicella-zoster virus
What are characteristics of streptococcus pyogenes?
- resistant to phagocytosis
- streptokinases lyse clots
- streptolysins are cytotoxic
What are symptoms of strep throat?
- local inflammation
- fever
- tonsillitis
- enlarged lymph nodes