Staphylococcus Flashcards
All cocci are gram +ve Except
VeNoM
Veilonella
Neisseria
Moraxella
Classification of Gram +ve Cocci
Micrococcacae - Staphylococcus, Micrococcus
Streptococcacae - Streptococcus, Pneumococcus, Enterococcus
Shape of Staphylococcus and Micrococcus
Bunch of grapes - S Aureus
Tetrad - Micrococcus
Glucose utilisation in Micrococcus and Staphylococcus
Oxidative - Micrococcus
Fermentative - S Aureus
Micrococcus and Staphylococcus are Catalase
Positive
Micrococcus and Staphylococcus are Oxidase
Micrococcus - Positive
Staphylococcus - Negative
Staphylococcus is Bacitracin
Resistant (Tough)
Micrococcus is Bacitracin
Sensitive
What is glucose utilisation medium
Hugh and Leifson (Bromothymol blue indicator)
S. Aureus produces which pigment
Golden pigment
Features of Staphylococcus aureus
Non motile
Non sporing
Catalase +ve
Oxidase -ve
Virulence factors of S Aureus associated with cell wall
Peptidoglycan, Teichoic acid
Virulence factor of S Aureus associated with cell surface
Protein A , Clumping factor
Features of Protein A
Anti-complementary
Anti-phagocytosis
Co-agglutination
In case of S Aureus , for co-agglutination test which strain is used
COWAN-1 Strain
Toxins produced By Staph aureus
Hemolysins
Panton-valentin toxin (PV Toxin)
Epidermolytic/Exfoliative toxin
Enterotoxin
Types of Hemolysin toxin
Alpha - Lyse sheep and human RBC, inactivated at 70° and activated at 100°
Beta/Sphingomyelinase - Lyse sheepn RBC only, Hot cold phenomenom
Gamma - Lyse sheep and human RBC
Delta - Same
Panton-valentin toxin is secreted by
Methicillin resistant Staph Aureus
Epidermolytic or Exfoliative toxin can cause
Staphylococcus scalded skin syndrome (SSSS)
Ritter’s disease
TEN(Toxic epidermal necrolysis)
Site of action of Epidermolytic toxin in Staphylococcus scalded skin syndrome
Stratum granulosum - Desmoglein 1
Most common Type of Enterotoxin
Enterotoxin A
Heat stable
Enterotoxin can cause
Food poisioning - Vagomimetic action - Vomiting
Incubation period for Food poisoning caused by Enterotoxin
1-6 hours
Enterotoxin F can cause
Toxic shock Syndrome