Unit 6b Flashcards
streptococci is classified based on
colony morphology and hemolytic reactions on blood agar
based on the antigenic nature of cell wall carbohydrates
Lancefield classification
developed Lancefield classification in the 1930’s
Rebecca C. Lancefield
best defined virulence of factor in S. pyogenes
M protein
M protein is encoded by the gene
emm
prevents opsonized phagocytosis by neutrophils or macrophages
hyaluronic acid capsule
may favor the spread of the organism through the tissues
hyaluronidase
causes the lysis of fibrin clots
streptokinase
rash caused by S.pyogenes
scarlet fever
incubation period of pharyngitis
1-4 days
a localized skin disease
impetigo
a rare infection of the skin and subcutaneous tissues observed frequently in elderly patients
erysipelas
can develop following deeper invasion by streptococci
cellulitis
characterized by a diffuse red rash that appears on the upper chest and spreads to the trunk and extremities
scarlet fever
an invasive infection characterized by rapidly progressing inflammation of necrosis
necrotizing fascitis
a condition in which the entire organ system collapses, leading to death
Streptococcal Toxic Shock Syndrome
typically follows S.pyogenes pharyngitis
rheumatic fever
characterized by fever and inflammation of hearts, joints, blood vessels, and subcutaneous tissues
rheumatic fever
colonis of S.pyogenes on blood agar are what?
small, transparent and smooth
it may be found as normal flora in the genitourinary tract
Streptococcus agalactiae
important virulence factor in infections with group B streptococci
capsule
appears to be the most significant component of the capsule and a critical virulence determinant
sialic acid
commonly infects newborns and pregnant women
Streptococcus agalactiae
occurs soon after birth
neonatal sepsis
the most important factor in infection is the?
presence of group B streptococcus in the vagina
drug of choice for neonatal sepsis
penicillin g or cefazolin
group b streptococci grown on blood agar as?
grayish white mucoid
normal flora of the respiratory tract
streptococcus pneumoniae
drug of choice for pneumoniae
penicillin or erithromycin
young cultures for strep pneuomoniae
round,glistening,wet,mucoid, dome-shaped
normal flora for the upper respiratory tract
Viridans streptococci
viridans means
green
endocarditis
infection of heart values
dental carries
strep. sanguis and strep. mutans
natural inhabitants of intestinal tract
enterococcus
most common species of enterococcus
E.faecium followed by E.faecalis
E.faecalis also produces a two-subunit toxin called as
cytotoxin
the most common infection for enterococcus
uti
often observed in patients receiving hemodialysis
entorococcal bacteremia
seen mainly in elderly patients with prosthetic heart valves
endocarditis
drug of choice for endocarditis
aminoglycoside with ampicillin or penicillin
encoded the emergence of vancomycin-resistant Enterococcus
vanAgene
lab identification for Enterococci
positive for bile esculin
often used for treatment of infections caused by vancomycin-resistant enterococci
linezolid
very similar to enterococcus on blood agar
aerococcus
a very similar to viridans streptococci on blood agar
leuconostoc
is aerococcus resistant or susceptible to vancomycin?
susceptible
is leuconostoc resistant or susceptible to vancomycin?
resistant
rare isolate in patients who have septicemia
pediococcus
is pediococcus resitant or susceptible to vancomycin?
resistant
