Exam 1 skin infections Flashcards
Describe the mechanism of a comedone formation
Oil creates an anaerobic environment for certain bacteria (propionibacterium acnes) and an immune response with neutrophils creates the pus/white head
What is the most common bacteria that causes acne?
Propionibacterium acnes
What causes impetigo?
Staphylococcus aureus and Streptococcus pyogenes
What is the most common cause of surgical infections?
Staph aureus
What is the tree of Staph aureus
Gram + cocci, catalase +, coagulase +
What are the virulent factors of staph aureus?
Protein A (Fc binding portion), coagulase (forms fibrin coat), hymolysins and leukocidins, hyaluronidase, staphylokinase, lipase
What causes toxic shock syndrome?
Staph aureus and Strep pyogenes
What causes scalded skin syndrome?
Staph aureus
What are the toxins released by staph aureus to cause scalded skin syndrome?
exfoliative toxins ET-A and ET-B that diffuse systemically
What is the tree of Streptococcus pyogenes?
Gram+ cocci, catalase -, Beta hemolytic, bacitracin
What are virulence factors of Streptococcus pyogenes?
Streptokinase, M protein, Hyaluronidase, DNase, Streptolysin O, Streptolysin S
What is the treatment of impetigo?
Mupirocin, pleuromutilin, oral cephalexin
What can cause cellulitis?
Staph aureus and strep pyogenes
What can cause gas gangrene
Clostridium perfringes
What is the tree for Clostridium perfringes?
Gram+ bacilli, spore forming, obligate anaerobe, non-motile
