Chapter 19: Respiratory System Infections-Part 1 Flashcards
Upper respiratory tract
Mouth Nose, nasal cavity Pharynx Epiglottis Larynx
Lower respiratory tract
Trachea
Bronchi
Bronchioles
Alveoli
The respiratory tract is the most common…
Portal of entry for microbes
First line defenses of respiratory system
Nasal hairs
Cilia
Second line defenses of respiratory system
Macrophages
Third line defenses of respiratory system
Pathogen-specific secretory IgA
IgA is primarily fond in..
Mucosal regions of the body
Normal biota are mainly found in the _____ respiratory tract
Upper
Gram _______ bacteria are common in the normal biota of the respiratory tract
Positive
Streptococci and staphylococci
Pathogenic strains of bacteria are kept in check by..
Other non pathogenic strains
Candida albicans
(Yeast), colonizes the oral mucosa
Streptococcal pharyngitis
Strep throat, on of most common diseases of URT
Symptoms of streptococcal pharyngitis
Difficulty swallowing, fever, red throat with pus patches, enlarged and tender lymph nodes
(localized to neck)
Causative agent of streptococcal pharyngitis
Streptococcus pyogenes
Streptococcus pyogenes characteristics
Gram positive
Coccus in chains
Beta hemolytic
Streptococcus progenies is commonly referred to as..
Group A streptococcus
Why is streptococcus progenies commonly referred to as group A streptococcus?
Due to group A carbohydrate in cell wall, basis for identification from other organisms
Pathogenesis of streptococcal pharyngitis is due to..
Numerous virulence factors
Streptococcal pharyngitis virulence factors
Streptolysin O and S
Protein G
More used in other diseases
Streptolysin O and S
Cause hemolysis
Protein G
Used to inactivate antibody
Complications of streptococcal pharyngitis infection
sequella
Scarlet fever
Acute glomerulonephritis
Acute rheumatic fever
Scarlet fever
Red rash and white coating on tongue
Rheumatic fever
Ab-Ag complexes
Streptococcal toxic shock syndrome
Super antigens cause cytokines and mass inflammatory response to occur
Acute glomerulonephritis and others can have..
Production of antibodies that accidentally cross react with heart valves and leave you with an auto immune disease
Rapid diagnostic tests (S pyognes)
On pharyngeal swab specimens
How do the rapid diagnostic tests work?
Use antibodies to detect group A streptococci
Bind to group A carbohydrate
Culturing
Of pharyngeal swab specimens
How does culturing of streptococcus pyogenes work?
- Plated on sheep blood agar
- S pyogenes causes beta-hemolysis
- Bacitracin disc test
What must be distinguished with the S. progenies culture?
Distinguish from beta-hemolytic group B streptococci and enerococci
Treatment for Strep
Penicillin as many group A streptococci resistant to erythromycin
What should you use for patients with penicillin allergies?
First generation cephalosporin
Prevention of strep
No vaccine
Hand washing
Common cold symptoms
Malaise Mild sore throat Runny nose Cough and hoarseness Nasal secretion
Common cold symptoms disappear in about..
1 week
Causative agent of common cold
30% - 50% caused by rhinoviruses
Rhinoviruses refer to the..
Nose
Characteristics of rhinoviruses
Non-enveloped, single-stranded RNA genome
First step in common cold pathogenesis
Virus attaches to specific receptors on respiratory epithelial cells and multiply in cells
What happens after viruses are released from infected cells in the common cold?
Injured cells cause inflammation which stimulates nasal secretion, sneezing and tissue swelling
Common cold infection is halted by..
Inflammatory response, interferon release and immune response
Common cold treatment
Supportive with OTC medications
