Streptococci Flashcards
Define streptococcus?
What are disorders of streptococcus?
gram-positive aerobic organisms
cause many disorders, including pharyngitis, pneumonia, wound and skin infections, sepsis, and endocarditis.
What are disorders caused by group A beta hemolytic?
group A beta hemolytic streptococci may include rheumatic fever and glomerulonephritis.
What are classification of streptococcus? Define each of them.
Which media is used for streptococcus
- Beta-hemolytic streptococci produce zones of clear hemolysis around each colony.
- Alpha-hemolytic streptococci (commonly called viridans streptococci) are surrounded by green discoloration resulting from incomplete hemolysis.
- Gamma-hemolytic streptococci are non-hemolytic.
they are grown on sheep blood agar
What is subsequent classification of streptococcus?
And depend on what?
Based on carbohydrates in the cell wall, divides streptococci into Lancefield groups A through H and K through T ( Lancefield Classification).
Some streptococcus don’t response to lancefield classification?
Streptococcus pneumoniae
What is streptococcus virulence factor?
Streptomycins, DNAases, and hyaluronidase
How does streptococcus stimulate immune system?
release exotoxins that activate certain T cells, triggering release of cytokines, including tumor necrosis factor-alpha, interleukins, and other immuno-modulators.
Which streptococcus is most pathogenic and from which class?
S. Pyogenes
which is beta-hemolytic and in Lancefield group A (GABHS)
What are diseases caused by GABHS?
- Pharyngitis
- Skin infections
-rheumati fever, acute glomerulonephritis
How can lymph nodes are affected by GABHS?
GABHS can spread through the affected tissues and along lymphatic channels (causing lymphangitis) to regional lymph nodes (causing lymphadenitis).
What are suppurations complications of GABHS?
GABHS can also cause local suppurative complications, such as peri-tonsillar abscess, otitis media, sinusitis, and bacteremia.
Which streptococcus cause pharyngitis?
GABHS
Define scarlet fever
Scarlet fever is caused by group A streptococcal strains that produce an erythrogenic toxin, leading to a diffuse pink-red cutaneous flush that blanches with pressure.
Explain streptococcal skin infection?
Impetigo is a superficial skin infection that causes crusting or bullae.
Erysipelas is a superficial cellulitis that also involves the lymphatics. Patients have shiny, red, raised, indurated lesion caused by GABHS,
Cellulitis involves the deeper layers of skin and may spread rapidly, toxins produced mainly by group A streptococci.
T/F Necrotizing fasciitis is prevalent among IV drug abusers.
True
What are symptoms of necrotizing fasciitis?
1 Fever 2 exquisite localized pain 3 diffuse and local erythema 4-Thrombosis 5-ischemic necrosis 6 - shock and renal dysfunction.
What is cause of streptococcal toxic shock syndrome?
Is similar to that caused by S. aureus, may result from toxin-producing strains of GABHS and occasionally from other streptococci.
What is rheumatic Fever caused by streptococci?
How to diagnose it?
How to prevent it?
An in flomevertary caused because of untreated GABH5 pharyngitis.
Diagnosis of a first episode is based on a combination of arthritis, carditis, chorea, specific cutaneous manifestations,
One of the most important reasons for treating GABHS pharyngitis (strep throat) is to prevent rheumatic fever.
What is poststreptococcal acute glomeruloneptritis?
What is side effect of treatment glomerulonephritis?
After a throat or skin infection with one of these strains, about 10 to 15% of patients develop acute glomerulonephritis
Antibiotic treatment of GABHS infection has little effect on development of glomerulonephritis.
What IS PANDA syndrome
(pediatric autoimmune neuropsychiatric disorder associated with group A streptococci) refers to a subset of obsessive disorders or tic disorders
T / F
Certain forms of psoriasis (eg, guttate) may also be related to beta-hemolytic streptococcal infections.
True
T/F pneumococcus capsule consists of a complex polysaccharide that determines serologic type and contributes to virulence and pathogenicity.
True
What is most important component of pneumococcus?
What are most important serotype. of pneumococcus?
pneumococcus capsule consists of a complex polysaccharide that determines serologic type
1 Serotype 3 strains, which are more heavily encapsulated and tend to form more mucoid colonies than other serotypes,
2 Serotype 19A, which is highly virulent and multidrugresistant,
Which patients are more susceptible to pneumococcal infection?
1-chronic illness 2-immunosuppression 3-sickle cell disease 4-Smokers 5-Alaskan natives
What is best drug fo uncomplicated or mild infection of streptococcus?
Which drugs used during resistant?
a beta- lactam or macrolide antibiotic.
cephalosporin (eg, ceftriaxone, cefotaxime, ceftaroline), a respiratory fluoroquinolone(eg, moxifloxacin, levofloxacin, gemiflox acin), and/or a tetracycline (eg, omadacycline).
What ‘is drug for severe pneumocaccul pneumonia?
combination therapy (eg, macrolide plus beta-lactam).
Which vaccine is recommended for children to prevent streptococcal infection?.
Routine vaccination with PCV13 is recommended for all children aged 2 months through 6 years
Streptopneumonia causes which disease?
MOPS Meningitis Otitis Pneumonia Sinusitis did
