Week 1 Bacterial Skin Infections - Diebel Flashcards
Acne/Folliculitis
infection of hair follicles by propionibacterium acnes
bacteria realease lipases to digest trapped oil, bacterial metabolism activates local inflammation
Impetigo
- most common in children
- skin flakes or peels off
- highly contagious
- can be caused by Staph or Strep
Staph Aureus
- most common infectous agent of surgical wounds
- Protein A (binds Fc portion of IgG)
- Coagulase (cloaking mechanism)
- Hemolysins and leukocidins (destroys RBCs WBCs)
FOR DEEP TISSUE INVASION-
Hyaluronidase
Staphylokinase
LIpase
TOXINS
TSST-1 (superantigen that promotes excessive release of IL-1 and TNF)
Scalded Skin syndrome- ET-A and ET-B (epidermis seperates skin and sloughs off)
Strep Pyogenes
Streptokinase M protein Hyalurondiase DNase Streptolysin O (destroys RBCs) Streptolysin S (destroys WBC)
TOXINS
TSS through exotoxin A (superantigen)
Necortizing fascitis through exotoxin B
Gram (-)
pseudomonas Arginosa causing hot tub folliculitis
Gram (+) Rod
Clostiridum Perfringens causes gas gangreen
Gram (+) Cocci
Strep and Staph
Catalase test
differentiate between strep(-) and staph (+)
Coagualse Test
differentiate between Staph auerus (+) and (straph saprofiticus and straph epidermis)
What causes is Cellulitis
Staph or Strep or clostridium
Clostridium Perfringens
non-motile
forms collections of gas under the skin that crackle when touched (crepitus)
bacteria grow in ANAEROBIC
To cure gas gangrene –> surgically remove, or hyperbaric oxygen, antibiotics not effective
Rocky Mountain Spotted Fever
Starts in extremities (hands and feet) spotted rash obligate intracellular parasite, needs host ATP!) get from ticks treat with doxycyclin
Lyme Disease
bulls eye rash
from ticks
