Ch. 24: Microbial Diseases of Respiratory System Flashcards
What is the primary cause of respiratory infections or follow a viral infection
Bacteria
What is streptococcus pyogens
streptococcal pharyngitis (strep throat); scarlet fever
(β-hemolytic strep —> S. pyogenes)
What are the upper respiratory tract infections?
-streptococcal; pharyngitis
-scarlet fever
-Diphtheria
What is scarlet fever
-erythrogenic toxin produced by lysogenized S. Pyogenes
-causes pinkish-red skin rash & fever
Is diphtheria uniform in shape?
No
What is corynebacterium diphtheria
Gram-positive, club-shaped rods/ pleomorphic; diphtheria; toxin producer; DTaP vaccine
What is streptococcal pharyngitis resistant to
-streptokinases lyse clots
-streptolysins are cytotoxic
How does the Diphtheria disease spread
begins with a sore throat & fever; spread by droplet transmission
In diphtheria what membrane forms
pseudomembrane
What is the pseudomembrane
tough, grayish membrane in the throat that can restrict airflow
What is a toxin producer
toxin circulates in the bloodstream, and interferes with protein synthesis
What immunization has limited Diphtheria cases to <5/year
DTaP vaccine
Diphtheria is what type of disease
cutaneous (infects the skin)
What are the lower respiratory tract diseases
streptococcus pneumonia, Legionella pneumophila, Bordetella pertusis
What is pneumonia
a disease, not a specific infection, caused by many types of microbes
What is streptococcus pneumonia (α-hemolytic)
typically a secondary infection
How is streptococcus pneumonia spread
airborne droplets
Streptococcus pneumonia has a capsule that prevents what
phagocytosis
Where does streptococcus pneumonia proliferate
alveolar spaces (like the bronchi; fluid build-up occurs)
Streptococcus pneumonia can spread to what
bloodstream & brain (meningitis)
What is the vaccine for streptococcus pneumonia
Pneumococcal polysaccharide vaccine (PPV)
What is legionella pneumophila
gram-negative, non-encapsulated, aerobic bacillus with a single, polar flagellum
Where is legionella pneumophila found
In fresh water
What type of parasite is legionella pneumophila
intracellular parasite invades and replicates amoeba in the environment (ubiquitous in nature)
In humans, L pneumophila invades and replicates inside what
macrophages via invasins
what is the the human infection of Legionella pneumophila
Inhalation of aerosols provided by cooling towers, air conditioners, hot tubs
What are the signs and symptoms of legionnaires disease
cough, shortness of breath, high fever, muscle pains, headaches; may have nausea & vomiting
What is the diagnosis of legionnaires disease
urinary antigen test & sputum culture
What is the prevention of legionella pneumophila
good maintenance of water systems
What is then treatment of legionnaires disease
with antibiotics
What is Bordetella pertussis
aerobic, Gram-negative coccobacillus
What does the Bordetella pertussis inhibit
the mucociliary escalator by binding to lung ciliated cells in the trachea, then progressively destroying them
What is the virulence factors of Bordetella pertusis
capsule; toxins
what is pertussis toxin
enters blood, results in systemic symptoms of disease
What is the catarrhal stage in Bordetella pertussis
resembles common cold
What is the paroxysmal stage
violent coughing; gasping for air; 1-6 weeks
What is the convalescence stage
months
What is the vaccine for Bordetella pertussis
DTaP vaccine
