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Staphylococcus
2/28/2011
44
Microbiology
Undergraduate 3
04/04/2011

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Cards

Term
betamethasone
Definition
12.6 mg
Term
Microscopic Morphorlogical Appearance of Staphlococcus
Definition

gram positive cocci

non-spore formers (can survive in relatively harsh condition)

non-motile

usually no capsule (aureus has capsule)

Term
Hemolysin
Definition

virulence factor- protein toxin


lyse RBC cells by disrupting cell membrane

Term
leukocidin
Definition

virulence factor-protein toxin

 

lyses white blood cells by disrupting cell membrane

Term
enterotoxin
Definition

virulence factor- protein toxin

 

food poisoning

Term
Toxic shock syndrome (TSST-1)
Definition

virulence factor- protein toxin

 

stimulates production of interleukin (IL-1) by macrophages resulting in fever induction

Term
coagulase
Definition

virulence factor - enzymes

 

plasma clotting protein; converts fibrinogen to fibrin

-coats bacteria with fibrin and prevents phagocytosis

-aids in attachment

Term
fibrinolysin
Definition

virulence factor - enzymes

 

digests fibrinogen (fibrin clots)

Term
hyaluronidase
Definition

virulence factor - enzyme

 

"spreading factor"

 

digests hyaluronic acid round host cells: promotes invation

Term
lipase
Definition

virulence factor - enzyme

 

degrades lipids: allows bacteria to colonize oily skin

Term
penicillinase
Definition

virulence factor - enzyme

 

hydrolyzes penicillin; drug resistance

Term
catalase
Definition

virulence factor - enzyme

 

degrades H2O2; a toxic metabolic end product

Term

exfoliatin

or

epidermolytoc toxin

Definition

virulence factor - enzyme

 

protease that causes peeling of superficial skin layers by dissolving intracellular bridges

Term
protein A
Definition

virulence factor- structural surface component

 

surface component linked to peptidoglycan layer of cell wall;

inhibits antibody-mediated clearance of bacteria by binding to IgG (non competitively binds-> decreases antibody immunity)

Term
lipoteichoic acid
Definition

virulence factor- structural surface component

 

binds to tissue components; cell adhesion

Term

staphylococcus aureus

 

carriage location?

carriage rate?

Definition

major pathogen of genus staphylococcus

 

anterior noses, nasopharynx and skin

 

30-50% of healthy adults

Term

virulence factors/ species identification of

 staphylococcus aureus

Definition

coagulase positive

hemolysin

leukocidin

protein A

capsule

Term
toxins of staphylococcus aureus
Definition

hemolysin, leukodin

enterotoxin

exfoliatin or epidermolytic toxin

Term
superficial infections caused by staphylococcus aureus
Definition
localized cutaneous infections
Term
toxigenic infections of staphylococcus aureus
Definition

staphylococcal scalded skin syndrome SSSS

(by exfolatin)

toxic shock syndrome TSTT-1

gastrointestinal disease (by enterotoxin)

Term

superficial cutaneous infections

symptoms, pathogenesis

 

Definition

pyodermic infection

systemic infections

 

pimples, boils, carbuncles and impetigo

symptom: pus formation, staphylococcus,

pyogenic cocci

Term
staphylococci invades skin at
Definition

sebaceous gland opening

hair folicle

wound

Term
primary infection sites for steph. aureus
Definition
faces, back of neck, buttocks
Term
symptoms of s. aureus
Definition
edema, erythema, pain, pus
Term
risk groups of s. aureus
Definition
elderly and young children with poor hygiene
Term
virulent feature of SSSS
Definition

exfolatin or epidermolytic toxin

 

spreads epidermal layer from the dermis, blistering and peeling of the skin, exposed red under layer

 

looks like burned skin

Term

mode of infection of SSSS

 

(how it starts, how it progresses)

Definition

syndrome begins as an erythema around the mouth and nose

 

spreads rapidly to infect skin of the neck, trunk and extremities 

Term
risk group of SSSS
Definition

infants, young children <4 yr

neonatal infection

Term
primary infected sites of SSSS
Definition

umbilical cord and eyes

low mortality rate

Term
death of SSSS
Definition
secondary infection of the denuded skin by other bacterial pathogens
Term
treatment of SSSS
Definition
topical antibiotic- mupirocin
Term
incidence of infection of Toxic Shock Syndrome
Definition
usage of super absorbent vaginal tampons that was cellulose based
Term
virulent feature of Toxic Shock Syndrome
Definition

toxic shock syndrome toxin

TSST-1

Term
mode of infection of Toxic Shock Syndrome
Definition

super absorbant brands strongly bind to Mg++ ions

low concentration of Mg++ triggers TSST-1 production which is absorbed into the bloodstream

TSST-1 that stimulates T-lymphocytes to produce cytokines intravascularly resulting in endothelial cell damage-shock and multi-system organ failure

Term
10 days later of Toxic Shock Syndrome
Definition

hands and soles of feet develop a sunburn-like rash which results in a peeling of the skin

 

"strawberry tongue"

Term
severe symptoms of Toxic Shock Syndrome
Definition
shock and multi-organ failure
Term
death rate of Toxic Shock Syndrome
Definition
2-5% respiratory failure
Term
source contamination of food poisoning
Definition
staphylococcal lesions of skin contaminates food then food is left unrefrigerated, room temperature grows s. aureus--> production of enterotoxin
Term
virulence factor of food poisoning
Definition
enterotoxin
Term
coagulase negative staphlococcus
Definition

s. epidermis

s. saprophyticus

Term
route of infection of coagulase negative s.epidermis
Definition

surgical procedures that involve the insertion of foreign bodies- heart, catheter, etc

 

attachment of bacteria to foreign body

Term
infections of s. epidermis
Definition
endocarditis, urinary tract infection, wound infection
Term
bacterial sensitivity or resistance to antibiotic
Definition

novobiocin

 

s.epidermis: sensitive (no growth)

s. saphrophyticus: resistant (growth)

 

under novobiocin disk

Term
emerging superbug?
Definition

MASA

 

methicillin resistant s.aureus

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