Respiratory Micro- Debiel/Zimmer Flashcards
What is the point of the turbinate bones (Baffle plates)?
Force air to swirl as it passes over them, causing potential pathogens to make contact with nasal mucus
Are bacteria or viruses more common in causing upper respiratory tract infecitons?
VIRUSES! By far!!
What is the mucociliary escalator?
What are its 2 basic parts?
covers most of the bronchi, bronchioles, and nose
- Mucus-producing goblet cells
- Ciliated epithelium
What do the ciliated epithelium do?
Continually beat, pushing mucus up and out into the thorat
Describe the pathogenesis of rhinovirus and how that can lead to a bacterial sinusitis
- virus binds to ICAM-1 on upper respiratory epithelial cells
- Replicates inside cells and spreads to surrounding tissues without killing it
- Local inflammation causes exudate and increased ICAM-1 expression
- Actually ENHANCES ability of virus to spread and causes further infection
- Exudate produces blocks air passageways which can lead to bacterial sinusitis or otitis media
What is sinusitis?
A bacterial secondary infection (a complication of a viral infection)
Common cold lasts what duration?
One week or less!
What are the two common causes of sinusitis?
- Streptococcus pneumoniae
2. Haemophilus influenzae
In what age group is Strep Pyogenes the most common cause of pharyngitis?
age 5-15 strep pyogenes is the most common cause, followed by viruses
Describe the pathogenesis of rhinovirus and how that can lead to a bacterial sinusitis
- virus binds to ICAM-1 on upper respiratory epithelial cells
- Replicates inside cells and spreads to surrounding tissues without killing it
- Local inflammation causes exudate and increased ICAM-1 expression
- Actually ENHANCES ability of virus to spread and causes further infection
- Exudate produces blocks air passageways which can lead to bacterial sinusitis or otitis media
What are the the 2 important bacterial infections for Pharyngitis?
S. pyogenes
C. diptheriae
What bug causes pneumonia in kids and a moderately severe common cold in adults?
Paramyxovirus (Parainfluenza virus)
Describe the viral characteristics of Rhinovirus?
RNA
Icosahedral nucleocapsid
Nonenveloped
+ssRNA nonsegmented (class IV)
What are the most common causes of aseptic meningitis?
Coxsackievirus
Echovirus
Mumps virus
When do symptoms reach their peak post-infection?
2-5 days
At what point are cells completely regenerated post Rhinovirus infection?
14 days
What is the most common cause of pneumonia in young children?
What does this cause in adults?
Paramyxovirus (Parainfluenza)
Moderately severe Common Cold
Describe the viral characteristics of Rhinovirus?
RNA
Icosahedral nucleocapsid
+ssRNA (class IV)
What are the 2 most common causes of acute bacterial rhinosinusitis?
Strep pneumo
H. influenzae
What are the most common causes of palm and sole rash?
Syphillis
RMSF
Coxsackievirus
What are the most common causes of conjunctivitis?
H. influenzae
Adenovirus
S. pneumo
What is the only DNA virus that causes Common Cold?
Adenovirus
What is the treatment for bacterial Rhinosinusitis?
Amoxicillin or azithromycin
What are the 2 most common causes of acute bacterial rhinosinusitis?
Strep pneumo
H. influenzae
What is the most common cause of fungal Sinusitis?
Aspergillus fumigatus
How do you treat fungal sinusitis?
Mechanical removal of fungal pathogen
If a patient has a fever greater than 102 and facial pain, are you thinking viral or bacterial?
BACTERIAL
What is the treatment for bacterial Rhinosinusitis?
Amoxicillin or azithromycin
Treatment of strep pyogenes pharyngitis should start within what time frame of first signs of infection?
9 days
What are the common findings in patients with viral and bacterial causes of pharyngitis?
Fever
Sore throat
Edema
Hyperemia of tonsils and pharyngeal walls
What symptoms strongly suggest a viral cause of Pharyngitis?
Conjunctivitis Cough Hoarseness Inflammation of mucus membrane Diarrhea
What symptoms may be present if someone has Strep pyogenes pharyngitis (strep throat)?
Headache
Nausea
Vomiting
Abdominal pain
What is required if you suspect S. pyogenes pharyngitis?
Rapid strep test
Treatment of strep pyogenes pharyngitis should start within what time frame of first signs of infection?
9 days
What is the only cause of pharyngitis that should be treated?
Streptococcus pyogenes because it can lead to several serious complications.
What is the most common cause of pharyngitis? (broad)
Virus
If a patient presents with bumps and film on their tongue along with a skin rash, what are you thinking?
Scarlet Fever
What is Strep pyogenes capsule made out of?
What does it do for the bacteria?
Hyaluronic Acid (HA) Prevents phagocytosis by macrophages
What 2 virulence factors does strep pyogenes use for invasion?
Protease
Hyaluronidase
How does Diptheria Toxin work?
Part B binds to cells to allow its entry into an endocytic vacuole.
The vacuole acidifies.
Then the active part A gets into the cells and screws up translation so the cells die!
What is the major treatment for S. pyogenes pharyngitis?
Penicillin
Erythromycin if allergic to penicillin
What can certain strains of S. pyogenes secrete to cause Scarlet Fever?
Exotoxins:
ssa, speA, speC
These are Superantigens!
If a patient presents with bumps and film on their tongue along with a skin rash, what are you thinking?
Scarlet Fever
Is strep pyogenes catalase + or -?
NEGATIVE
What is the most common cause of pneumonia in young children?
RSV
How does Diptheria Toxin work?
Part B binds to cells to allow its entry into an endocytic vacuole.
The vacuole acidifies.
Then the active part A gets into the cells and screws up translation so the cells die!
Describe the bacterial properties of C. diptheriae.
Gram + Bacilli
What is the signature symptom of Croup?
Bark-like cough
When do croup symptoms peak?
When do they resolve?
peak 3-5 days
resolve 4-7 days
What does RSV have that causes cell membranes of nearby cells to fuse?
What do you call the result of multiple cells fusing?
F protein
Syncytium
What is the most common cause of pneumonia in young children?
RSV
What causes Life-threatning Epiglottitis?
Looking for 2 things
Beta Hemolytic strep
Haemophilus influenzae type b (Hib)
Common cold symptoms.
Nasal discharge
mild sore throat
cough
LACK OF FEVER (children may have fever)
What are 3 classic components of sinusitis?
FEVER
Purulent nasal discharge
Sinus Tenderness
Most common cause of pharyngitis in young kids and adults?
viruses
Most common cause of pharyngitis in kids age 5-15?
Strep pyogenes
What is the most serious risk of Laryngitis/Croup?
Airway obstruction
2nd most common cause of common cold?
Coronavirus
What normally causes Severe Acute Respiratory Syndrome?
Coronavirus
couldn’t you use a Corona right about now?;)
Describe the pathogenesis of Influenza C causing the common cold.
Viral Hemagglutinin A contacts the mucosas sialic acid and is endocytosed. Viral neurominidase (NA) cleaves HA bound to sialic acid and permits viral spread
Immune system produces IL-1 and IFN-gamma in response!
What is a cause of common cold and also causes 50 % of cases of viral myocarditis?
Cocsackie B
Strep pyogenes: 4 major virulence factors
Streptokinase (plasminogen-->plasmin) M protein (resists phagocytosis) Hyaluronidase (breaks down connective tissue) DNase (breaks down DNA)
What antibodies can you look for in a person with strep pyogenes infection?
Anti-Streptolysin O antibodies
Black bacteria makes you think of what bacteria?
Diptheria!
What does Strep pyogenes use for attachment? 3 things
M protein
Lipoteichoic acid
Fibronectin binding protein (protein F)
Why is strep pyogenes not phagocytosed?
Hyaluronic Acid capsule
What does adenovirus use to bind mucosa cells?
Hemagluttinin A
2nd most common cause of bacterial pneumonia in COPD patients?
Moraxella catarrhalis
Gray pseudomembrane
Airway obstruction
What bug ya thinking?
Corynebacterium diptheriae
What does C. diptheriae ribosylate to prevent protein synthesis?
EF-2
What 2 bacteria did we learn that are Quellung +?
Strep pneumo
Hib
What are the 2 major virulence factors of RSV?
G protein-attachment
F protein-Synctium
What bugs forms a syncytium?
RSV
What viruses bind using Hemagluttinin A?
Influenza C
Adenovirus
Parainfluenza
What cleaves HA from sialic acid?
Neuroaminidase
Treatment for C. diptheriae?
Antitoxin
Penicillin (or erythromycin)
What condition shares a similarity in symptomology with RSV?
What is the symptom?
Asthma
Wheezing
What bugs have an IgA protease?
Strep pneumo
Hib
MOST COMMON CAUSE OF EPIGLOTTITIS
H influenza type b
MOST COMMON CAUSE OF CROUP
Parainfluenza virus
Gram + Bacilli
Aerobic
Black colonies on potassium tellurite
C diptheriae
Tx for Hib?
Close contacts of infected person?
3rd Gen cephalosporins
(Hib vaccine for prevention)
Rifampin for close contacts
Gram +
Diplococci
alpha hemolytic
Strep pneumo
Helical
Enveloped
Class IV
Coronavirus
Nonenveloped
Icosahedral
Class IV
Rhinovirus
Tongue paralysis in young immigrant girl
DIPTHERIA!
Gram - coccobacilli
H flu
Factors V and X required for growth
H flu
