Shared Flashcard Set

Details

Streptococci
3/2/2011
39
Microbiology
Undergraduate 3
04/04/2011

Additional Microbiology Flashcards

 


 

Cards

Term
classification of streptococci is done by looking at
Definition

hemolytic pattern

alpha: producing hydrogen peroxide

none (gamma)

beta: completely lysing blood cell

Term

beta hemolytic pattern is further classified into__

based on __

Definition

Lancefield groups

group-sepcific carbohydrate

this binds to specific antigen on bacteria surface

Term
lancefield grop A represntative species is/are
Definition
Streptococci pyogenes
Term

lancefield group A s. pyogenes 

 localized infections include

Definition

pharyngitis "strep throat"

impetigo (superficial skin infection)

cellulitis/ erysipelas (deeper skin infection)

skin/soft tissue infection

scarlet fever rash

 

Term

lancefield group A s. pyogenes 

invasice infections include

Definition

necrotizing fasciitis

"flesh-eating infections"

 

bacteremia

steptococcal toxic chock syndrome

 

Term
symptoms of s. pyogenes incfections are/is
Definition

asymptomatic colonization is common

 

in respitory tract, nouth, skin

Term
risk group for s. pyogenes:
Definition
children in 1-15 yo
Term
transmission method for s. pyogenes
Definition
vis droplets in a shared environment
Term
major virulent factor of steptococci
Definition

M protein

 

(anti-phagocytic)

Term
what is the function of capsule in s. pyogenes?
Definition

virulent factor

protects against complement-mediated phagocytic killing

Term

one of the hemolysins

family of large, growing toxins

cholesterol-dependent

pore forming

oxygen-labile hemolysin

Definition
Streptolysin O
Term
upon cholesterol binding, pore is formed by ___
Definition
NASase
Term

one of the Hemolysins

oxygen-sable hemolysin (responsible for beta-hemolysis)

non-immunogenic

 

Definition
streptolysin S
Term
name two hemolysins
Definition

streptolysin O

streptolysin S

Term
superanigens involved in scarlet fever rash
Definition

SpeA and C

 

tjey are pyrogenic exotoxins (erythrogenic toxins)

 

toxic activation of immune system!

Term
steps in pathogenesis
Definition

colonization

local infection/invasion

dissemination/invasive disease

 

Term
major virulent factors that is involved in pathogenesis are
Definition

Hyaluronic acid capsule (anti-phagocytic)

SLO (resist ingestion during colonization)

M protein (anti-phagocytic)

Term
diagnosis of s. pyogenes
Definition

rapid strep antigen detection test : detects group A carbohydrate

only 75% sensitive

 

culture on blood agar (beta hemolytic colonies)

Term
treatment of s. pyogenes
Definition

penicillin

erythromyocin

Term
any vaccines for s. pyogenes?
Definition
nope
Term
hemolytic pattetn for s. pneumoniae
Definition

alpha-hemolytic

(no streptococcal antigen)

Term
charactristics of s. pneumoniae
Definition

gram positive, alpha-hemolytic

bile sensitive

opotochin-sensitive

diplococcus

Term
symptoms of s. pneumoniae
Definition

asymptomatic carrier/colonization

 

 

Term
localized infection of s. pneumoniae
Definition

pneumonia (mostly elderly)

 

otitis media (mostly children)

Term
invasive infection of s. pneumoniae
Definition

bacteremia/ sepsis

 

meningitis

Term
transmission of s. pneumoniae
Definition

via droplet

 

exclussively human pathogen

 

Term
leading vaccin-preventable killer of children
Definition
invasive pneumococcal disease
Term
diagnosis of pneumonia is popularly done by
Definition
chest x-ray
Term
other diagnostic methods?
Definition

microscopy from source (gram+ cocci)

bile sensitive and optochin sensitive

Term
treatment for s. pneumoniae?
Definition

penicillin

 

(antibiotic resistance rising)

Term
are there vaccines for s. pneumoniae?
Definition

yes

 

prevnar, polysacchride conjugate vaccins (2000)

Term
group B representative species
Definition
s. agalactiae
Term
s. agalactiae infections include
Definition

neonatal pneumonia

sepsis

Term
virulence factors for s. agalactiae
Definition
capsule, beta-hemolysin, adhesin, Cda peptidase
Term
s. mutans, mitis, salvivarius, thermophilus, sanguinis are
Definition

virudans group

(no antigen)

Term
viridans streptococcus infections include
Definition

caries

endocarditis

Term
diagnosis of viridans streptococcus
Definition

alpha-hemolytic

optichin-resistant

bile-resistant

Term
treatment of viridans s.
Definition
penicillin
Supporting users have an ad free experience!