Chapter 22

Streptococcus pyogenes respiratory diseases

Streptococcal pharyngitis (strep throat)

Scarlet fever

Strep throat virulence factors

Streptolysins, cytotoxic to many cell types

streptokinases, lyse fibrin clots

M protein, inhibits compliment system

Capsule, inhibits phagocytosis

strep throat signs and symptoms

sore throat, fever, tonsillitis

Scarlet fever virulence factor

erythrogenic toxin

Diphtheria etio agent

Corynebacterium diptheriae

gram positve pleomorphic rod

resistant to drying

diphtheria virulence factor

pathogenic strains are toxinogenic very low LD50

diphtheria syndromes

toxemia (kidney and heart damage)

sore throat and fever

swelling in airways

Pertussis etio agent

Bordetella pertussis (whooping cough(

pertussis virulence factors

capsule,

pertussis toxin

tracheal toxin kills ciliated cells

TB etiological agent

mycobacterium tuberculosis

obligate aerobe,

TB virulence factors

resistant to drying up and chemicals

mycolic acid cell wall

multiplies in macrophages

TB syndromes

activated macrophages for tubercules in lung tissue followed by systemic innfection

long term: persistent fever, blood in cough, weight loss and weakness

Pneumococcal pneumonia etio agent

streptococcus pneumoniae

gram + cocci, large capsules

pneumococcal pneumonia virulence factor

capsule

pneumococcal pneumonia syndrome

quick onset high fever, heavy breathing, chest pain, fluid in the lungs

Mycoplasma pneumonia etiological agent

mycoplasma pneumoniae

(wall less pleiomorphic)

mycoplasma pneumonia symptoms

mild but persistent respiratory symptoms, low fever, cough, headache

"walking pneumonia"

Legionnaires diseases etiological agent

legionella pneumophila

(gram - rod, multiply in water bound amoeba)

Legionnaire's portal of entry

aerosols, (AC units), not human to human

Legionnaire's syndromes

potentially fatal pneumonia tends to affect smokers and drinkers