Staphylococcus - Dermatology - Lecture Slides, Slides of Dermatology

Download Staphylococcus - Dermatology - Lecture Slides and more Slides Dermatology in PDF only on Docsity!

Staphylococcus

Classification

• Family
• Genus
• Species

Micrococcaceae

Micrococcus and Staphylococcus

S. aureus S. saprophyticus S. epidermidis more M. luteus than 20 specie s Docsity.com

Morphology

Morphology

Staph vs. Strep

Gram-positive cocci

in clusters

Staphylococcus

MICROBIAL PATHOGEN ADHESIN RECEPTOR

Staphylococcus aureus LiLippootteeiicchhooiicc aacciidd^ Unknown Staphylococcus spp. SlSliimmee llaayyeerr^ Unknown Group A Streptococcus LTLTAA--MM pprrootteeiinn ccoommpplleexx^ FFiibbrroonneeccttiinn Streptococcus pneumoniae Protein N-acetylhexosamine-gal Escherichia coli Type 1 fimbriae CFA 1 fimbriae P fimbriae

D-MaMannnnoossee GM gaganngglliioossiiddee P blood grp glycolipid Other Enterobacteriaceae Type 1 fimbriae D-Mannose Neisseria gonorrhoeae Fimbriae GD 1 ganglioside Treponema pallidum P 1 , P 2 , P 3 Fibronectin Chlamydia spp. Cell surface lectin N-acetylglucosamine Mycoplasma pneumoniae Protein P1 Sialic acid Vibrio cholerae Type 4 pili Fucose and mannose

Cell-Associated Virulence Factors

• Capsule or slime layer (glycocalyx)
• Peptidoglycan (PG)
• Teichoic acid is covalently linked to PG and is species specific:

S. aureus ribitol teichoic acid

(polysaccharide A)

S. epidermidis glycerol teichoic acid

(polysaccharide B)

• Protein A is covalently linked to PG
• Clumping factor (bound coagulase )

Virulence Factors: Exotoxins

• Cytolytic (cytotoxins; cytolysins)  Alpha toxin - hemolysin - Reacts with RBCs  Beta toxin - Sphingomyelinase  Gamma toxin - Hemolytic activity  Delta toxin - Cytopathic for: - RBCs - Macrophages - Lymphocytes - Neutrophils - Platelets - Enterotoxic activity  Leukocidin Docsity.com

• Enterotoxin
• Exfoliative toxin (epidermolytic toxin)
• Pyrogenic exotoxins

Virulence Factors: Exotoxins

Clinical Manifestations/Disease

• SKIN

 folliculitis

 boils (furuncles)

 carbuncles

 impetigo (bullous & pustular)

 scalded skin syndrome

• Neonates and children under 4 years

Clinical Manifestations/Disease

• Other infections

 Primary staphylococcal pneumonia

 Food poisoning vs. foodborne disease

 Toxic shock syndrome

Coagulase-Negative Staphylococci

• Staphylococcus epidermidis
  • S. saprophyticus

Staphylococcal Lab ID & Diagnostic Tests

• Microscopic
• Lab isolation
• Coagulase positive

 S. aureus