Term
|
Definition
STREP:partial breakdown
translucent green zone in the blood agar
surrounding the α-hemolytic colony. |
|
|
Term
|
Definition
STREP:is a complete breakdown
clear zone surrounding beta-hemolytic colony |
|
|
Term
|
Definition
|
|
Term
the most common
cause of streptococcal diseases in humans. |
|
Definition
STREP:Group A streptococci consist of a single species called
Streptococcus pyogenes.
Lancefield groups |
|
|
Term
| (Lancefield groups A & B) are |
|
Definition
|
|
Term
|
Definition
STREP:covers the surface of Group A strep cells
and prevents their peptidoglycan from activating the
alternate complement pathway & being opsonized by C3b |
|
|
Term
|
Definition
helps Group A streptococcus
cells evade phagocytosis in 2 ways.
1) It covers Group A streptococcus cells and prevents their
peptidoglycan from activating the alternate complement
pathway (ACP) and being opsonized by C3b.
2) It camouflages the bacterial cells from host phagocytes
because hyaluronic acid is a normal component of
connective tissue. |
|
|
Term
| Two distinct streptokinases |
|
Definition
STREP: enzymes that
dissolve blood clots.
1) They allow Group A streptococcal cells to invade
small wounds in skin by dissolving the clot. |
|
|
Term
|
Definition
STREP:deoxynuclease that breaks
down DNA. |
|
|
Term
|
Definition
STREP:a protease that inactivates C5a
(a potent chemotactic factor and phagocyte activator). |
|
|
Term
|
Definition
STREP: and STAPH:dissolves hyaluronic acid (the
major component of the intercellular matrix in
connective tissue).
1) It enables Group A streptococci to spread in tissue. |
|
|
Term
| Pyrogenic (erythrogenic) toxins A, B and C, |
|
Definition
STREP: superantigens that non-specifically activate T cells to synthesize and release inflammatory cytokines such as
TNF-α. The superantigens enter the circulation and cause
the red skin rash of scarlet fever, fever and shock. |
|
|
Term
|
Definition
STREP:which lyse red blood cells, white
blood cells and platelets. |
|
|
Term
|
Definition
| STREP:kills white blood cells |
|
|
Term
|
Definition
STREP: (Impetigo)
\superficial, pus-producing
skin infection that forms crusty
sores on the face, arms or legs.
2. Is a common infection in
children.
Is readily treated with
antibiotics, and should be
treated promptly.
4. *Group A streptococci are the
most common cause of
impetigo in individuals over
2 years of age.* |
|
|
Term
|
Definition
STREP:
spreading infection in
the deep layer of skin caused by
group A streptococcus
intense inflammation and fever, and
must be treated promptly with
antibiotics to prevent dissemination
of Group A strep to deeper tissues
and organs. |
|
|
Term
|
Definition
STREP:begins as a Group A strep throat
infection (group A strep pharyngitis).
High fever develops, the tongue turns
bright red and a rash spreads across
the body, especially the lower trunk.
3. Scarlet fever is caused by group A
strep *pyrogenic toxins* that enter the |
|
|
Term
| Group A Streptococcus Toxic Shock Syndrome |
|
Definition
STREP:
life-threatening septicemia with invasive *pyrogenic toxin* producing Group A strep strains
associated
with certain M protein types (1 and 3). |
|
|
Term
|
Definition
STREP:. Is a rapidly spreading, life-
threatening infection of
fascia, the connective tissue
covering muscle.
*the flesh-eating infection.*
3. It can be initiated by getting a
small cut or bruise on skin
harboring Group A strep.
4. Amputation is usually the only treatment.
5. Invasive Group A streptococcus infections are a reportable
disease. There are about 5,000 cases per year in the U.S. |
|
|
Term
|
Definition
STREP:
autoimmune disease
caused by the formation of
antibodies to a Group A
streptococcus antigen that
also cross-react with (bind)
antigens present in the human
heart and other tissues
characterized by carditis,
arthritis, formation of skin
nodules, chorea and fever.
3. It causes permanent damage to
heart valves and heart muscle,
and a life long susceptibility to
getting infective endocarditis
Painful arthritis and formation
of subcutaneous nodules called
rheumatoid nodules are common
sequela to carditis (heart muscle
inflammation) in the acute phase
of rheumatic fever.
(sponateously deissolve 3-6 months)
Group A streptococcus rheumatic fever and scarlet
fever infections were the #1 infectious killer of
children in the U.S. in the early 20th century.
A. Mandatory milk pasteurization and the discovery and
use of penicillin have virtually eliminated these
diseases from the U.S |
|
|
Term
|
Definition
caused by the formation of soluble circulating
antigen-antibody complexes containing group A
streptococcus antigens in the bloodstream that
become trapped in renal glomeruli in the kidneys
inflammation and Type III hypersensitivity in the
renal glomeruli, causing the glomeruli to fail to
filter blood normally.
Severe cases of streptococcal glomerulonephritis
destroy the glomeruli and cause kidney failure. |
|
|
Term
| Treatment of Group A Strep Infections |
|
Definition
Penicillin is the antibiotic of choice
Erythromycin is used in hosts allergic to penicillin. |
|
|
Term
| Group B Streptococcus: Streptococcus agalactiae |
|
Definition
Are not inhibited by bacitracin (the A taxo disk).
normally
colonize the vagina, urinary tract and lower G.I. tract of humans.
causes infections primarily in neonates who
are born to mothers who have not formed IgG antibodies
to S. agalactiae
septicemia, meningitis and pneumonia in neonates.
1) 60% of neonates are infected during birth.
2) This infection is life-threatening in 3/1000. There is a
5% mortality rate in this 3/1000 group and 25% suffer |
|
|
Term
| Subacute infective endocarditis |
|
Definition
Viridans streptococci enter blood during dental
procedures that cause bleeding, and are the
leading cause of subacute infective endocarditis
characterized by the
formation of vegetative growths of bacteria and fibrin on
heart valves,
The valves do not close properly or pump blood efficiently,
& produce a backflow of blood that causes a heart murmur |
|
|
Term
|
Definition
The major species are S. mitis, S. salivarius, S.
sanguis, S. milleri and S. mutans.
normal inhabitants of the mouth,
pharynx, GI tract, genital tract and urinary tract.
5. Viridans streptococci have low pathogenic potential, but can cause opportunistic infections such as Dental abscesses Dental caries
Infective endocarditis
Subacute infective endocarditis |
|
|
Term
| Factors That Enable S. pneumoniae to Cause Disease |
|
Definition
Phosphorylcholine in its cell wall stimulates host
epithelial cells in the lungs, meninges and blood
vessels to phagocytize S. pneumoniae cells.
A. This enables S. pneumoniae cells to multiply inside
epithelial cells, protected from host phagocytes.
2. It produces a polysaccharide capsule that protects
it from ingestion and killing by host phagocytes.
It has a protein adhesin in its cell wall that
mediates its attachment to epithelial cells in the
pharynx, enabling it to colonize the pharynx
4. S. pneumoniae secretes a secretory IgA protease that
destroys secretory IgA.
Pneumolysin is a toxin that lyses ciliated epithelial
cells and inhibits the killing of phagocytized S.
pneumoniae cells by disrupting lysosomes |
|
|
Term
|
Definition
Is a life-threatening infection caused
by aspiration of S. pneumoniae into
the lungs. S. pneumoniae multiplies in
the alveoli causing inflammation, pus
formation and damage to the alveoli.
S. pneumoniae accounts for 60% of
pneumonia cases needing hospitalization.
A. Most cases occur in elderly or very
young hosts after a viral infection. |
|
|
Term
|
Definition
1. Sinusitis is inflammation of a sinus cavity.
A. Sinusitis is characterized by inflammation and swelling
of the mucous membranes in the sinus, causing closure of
the sinus cavity, pressure and pain in the sinus.
2. Viral infection is the most common cause of
sinusitis (>90% of cases), but it can also be caused
by bacterial infection and allergy.
3. S. pneumoniae is one of the most common causes of
bacterial sinusitis.
4. Bacterial sinusitis is usually a secondary infection
that follows a viral infection of the sinuses. |
|
|
Term
| Pneumococcal Otitis Media |
|
Definition
Otitis media is an infection of the middle ear.
A. Otitis media is characterized by inflammation and
swelling of the mucous membranes in the middle ear,
causing pressure and pain in the middle ear.
2. S. pneumoniae is the most common cause of otitis
media, which is a common disease in children. It is
usually a self-limiting disease, lasting 4 to 6 weeks.
3. Antibiotic treatment rarely affects the outcome of
otitis media, but they are frequently prescribed
because parents demand it and it may help prevent
spread of the pathogen to other sites in the body.
A. Unfortunately this practice has resulted in the emergence
of antibiotic-resistant S. pneumoniae strains. |
|
|
Term
|
Definition
If S. pneumoniae enters
the bloodstream, it can: enter cerebral spinal fluid and cause meningitis
S. pneumoniae meningitis is a life-threatening
infection of the meninges & has a high mortality rate.
A. The symptoms of meningitis are severe headache, fever,
pain & stiffness in the neck, nausea and vomiting. Coma
and death occur in 1-2 days without antibiotic treatment.
B. S. pneumoniae is currently the most common cause of
meningitis in the U.S., causing about 5,300 cases/year.
Half of the cases are in children <5 years of age. It is why
the pneumococcal vaccine is now given to all children. |
|
|
