Term
| What are the anatomical defense mechanisms of normal skin? |
|
Definition
| epidermis stratum corneum and dermis |
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Term
| What are the biochemical defenses of the skin? |
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Definition
| keratin, salt, fatty acids, lysosyme, and antimicrobial peptides |
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Term
| What are other mechanisms of the skin's defense? |
|
Definition
| sloughing, pH, available moisture, and surface temperature |
|
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Term
| What are the characteristics of normal flora of the skin? |
|
Definition
| resistance to drying, resistance to salt, grow in clumps |
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Term
| What are the differnt species of organisms found in normal flora of the skin? |
|
Definition
1. Staphylococcus epidermidis (Micrococcus sp.)
2. Diptheroids (Propionibacterium acne)
3. Candida (yeast)
4. Staph Aureus |
|
|
Term
| What are the 3 ways that pathogens attack the skin? |
|
Definition
1. breach of intact skin (no damage to skin)
2. skin manifestation of a systemic infection
3. toxin-mediated skin damage |
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Term
|
Definition
| in the surface layer of the skin, filled with clear fluid |
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Term
|
Definition
| fluid filled larger vesicles |
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|
Term
|
Definition
| not raised, no pus or fluid, but it's red |
|
|
Term
| What is a papule? what are the other names for it? what is an example of this? |
|
Definition
| in the deeper layers of the skin (dermis), filled with pus not clear fluid; furuncle or carbuncle; cellulitis |
|
|
Term
| What is folliculitis? what is a sty? |
|
Definition
| hair follicle infection; infection of eyelash |
|
|
Term
| What type of gram stain is staphylococcus aureus? |
|
Definition
| gram positive cocci in cllusters |
|
|
Term
| What infections of the skin does Staph aureus cause? |
|
Definition
| folliculitis, sty, cellulitis and boils (can result in abscess) |
|
|
Term
| What is cellulitis? boils? |
|
Definition
| somewhat on the surface (can see the pus through skin); deep, red, raised (can't see the pus it is so deep) |
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Term
|
Definition
| pussy infection that moves into the blood (since they are located in the dermis next to blood vessels) and they can block the blood vessels (can't treat with antibiotics because they can't get to the site of infection) |
|
|
Term
|
Definition
| large vessicles on the skin, it's crusty and sticky (because serum or plasma from blood leaks out) |
|
|
Term
| What is the epidemiology of Staph aureus? |
|
Definition
| carrier stte is in the nose, transmission by fomites, community acquired MRSA |
|
|
Term
| What are the virulence factors of S. Aureus? |
|
Definition
| coagulase, protein A, Toxins, Capsule, extracellular products |
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|
Term
| What is coagulase's role as a virulence factor? |
|
Definition
| coats bacteria with clot material so the body recognizes it as self and they clump |
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|
Term
| What is Protein A's role as a virulence factor? |
|
Definition
| binds to the Fc region of an antibody (which is the wrongg side, so they are oriented backwards) |
|
|
Term
| What is a toxins role as a virulence factor? |
|
Definition
| binds to Fc region of IgG (orienting them backwards_ |
|
|
Term
|
Definition
| breaks up the layers of the cells in the skin so they can invade between them |
|
|
Term
| How would you diagnose S. Aureus infection? |
|
Definition
| microscopy (gram stain), selective differential medium (MSA blood agar), Catalase +, Coagulase + |
|
|
Term
| What is the purpose of a catalase test? |
|
Definition
| see if bubbles occur to determine if the orgnaims is aerobic |
|
|
Term
|
Definition
| methicillin resistant staph aureus |
|
|
Term
| What antibiotic would you treat HA-MRSA with? |
|
Definition
|
|
Term
| what is the methicillin resistance coded for the MRSA? |
|
Definition
|
|
Term
| What verifies MRSA as a CA strain? What is this? |
|
Definition
| PVL leukocytin; protein that kills leukocytes |
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|
Term
| How do you treat staph aureus? |
|
Definition
| penicillin (normal circumstances), methicillin (sensitive), synercid (new antibiotic) |
|
|
Term
| How do you prevent infection by staph aureus? |
|
Definition
| cleanliness, maintain innate immunity, new vaccine for compromised patients |
|
|
Term
| Who is at high risk for getting infected with staph aureus? why? |
|
Definition
| dialysis patient; they have a permanent influx into skin because they have a tube going into them |
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|
Term
| What is responsible for the symptoms of an infection with staph aureus toxemias? |
|
Definition
| toxins (there is no bacteria at the site of skin manifestation) |
|
|
Term
| What does scalded skin syndrome come from? |
|
Definition
|
|
Term
| What are the characteristics of scalded skin syndrome? |
|
Definition
| bacteria colonize on intestine newborn and children <2, toxin enters bloodstream, toxin affects epidermis |
|
|
Term
| What are the virulence factors of scalded skin syndrome? |
|
Definition
| exfolative toxin A and B (destruction of intracellular connective tissue, skin peels off in sheets) |
|
|
Term
| What causes toxic shock syndrom? |
|
Definition
|
|
Term
| What are the characteristics of toxic shock syndrome? |
|
Definition
| colonization elsewhere, toxin enters bloodstream, body-wide effects |
|
|
Term
| What are the "body-wide effects" of toxic shock syndrome? |
|
Definition
| fever, vomiting, sunburn-like rash, peeling |
|
|
Term
| What is the epidemiolgy of toxic shock sundrome? |
|
Definition
| nasal surgeries, tampons in too long |
|
|
Term
| What are the virulence factors of toxic shock syndrome? what does it do? |
|
Definition
| TSST-1 (toxic shock syndrome toxin); super antigen that has the ability to induce massive inflammation |
|
|
Term
|
Definition
| culture on blood agar from site of TSS, verify the TSST-1 |
|
|
Term
| What type of gram stain is streptococcus pyogenes GROUP A? |
|
Definition
| gram possitive cocci in chains |
|
|
Term
| Which has a greater invasiveness, strep pyogense or staph? |
|
Definition
|
|
Term
| What infections does group a strep cause? |
|
Definition
| impetigo (vesicles), erysipelas, and late sequelae (secondary complications after the infection)W |
|
|
Term
|
Definition
| infection of the dermal layer by group a strep (flat and red since the infeciton is deep), causes tissue destruction, and can lead to sepsis |
|
|
Term
|
Definition
| when the infection gets into the blood |
|
|
Term
| What is the epidemiology of group A strep? |
|
Definition
| aerosol, pharynx (carrier state), direct contact with lesion |
|
|
Term
| What does it mean when something is in a carrier state? |
|
Definition
| NOT NORMAL FLORA = they have a pathogen that's not supposed to be there but there are no symptoms |
|
|
Term
| what is the treatment for group A strep? |
|
Definition
| quarantine and antibiotics |
|
|
Term
| What are the virulence factors of group A strep? |
|
Definition
| hyaluronic acid capsule, M protein, lipoteichoic acid, exotoxins, and streptokinase |
|
|
Term
| How is the M protein a virulence factor? for what? |
|
Definition
| mimics human proteins so your body recognizes them as self and won't moount an immune response (inhibits phagocytosis); group a strep |
|
|
Term
| How is lipoteichoic acid a virulence factor? of what? |
|
Definition
| anchors bacteria to host cells; group a strep |
|
|
Term
|
Definition
| exotoxins of group a strep that break up the neurtrophil net |
|
|
Term
| What are the exotoxins of group a strep? |
|
Definition
| streptolysins (O), streptokinases, hyaluronidase, DNAse, leukocidins, and erythrogenic toxins |
|
|
Term
| What do hyaluronidases do? |
|
Definition
| they are hemolysins for group a strep |
|
|
Term
| How do you diagnose group a strep? |
|
Definition
| microscopy (gram + cocci in chains), culture (beta hemolytic), group A carbohyrate |
|
|
Term
| How do you treat group A strep? |
|
Definition
| antibiotics, must prevent late sequelae |
|
|
Term
| What is the late seequelae of group a strep? when does this occur? |
|
Definition
| AGN (infection or inflammation of kidney nephrons), immune complex disease; after infections with skin M types of strep pyogenes (no live bacteria because there is no bacteria there, your body makes antibodies against the M types) |
|
|
Term
| What is Acute glomerulus? |
|
Definition
| causes kidney damage resulting in the patient needing dialysis (associated with skin infections of group A strep) |
|
|
Term
| Is there a vaccine for group A strep? |
|
Definition
| no, there is no prevention |
|
|
Term
| What causes necrotizing facitis? |
|
Definition
| streptococcus pyogenes toxemia |
|
|
Term
| What happens in necrotizing facitis? |
|
Definition
| "flesh eating strep" - rapidly destroys tissue as quickly as it's removed |
|
|
Term
| Can necrotizing facitis result in death? |
|
Definition
|
|
Term
| What are the virulence factors for necrotizing facitis? |
|
Definition
| pyrogenic exotoxin A (its a super antigen) |
|
|
Term
| How do you diagnose necrotizing facitis? |
|
Definition
| culture on blood agar (beta hemolytic group a), immunological assays for toxin (to verify presence of toxin) |
|
|
Term
| How do you treat necrotizing facitis? |
|
Definition
| antibiotics (penicillin), scrub out the wound |
|
|
Term
| What causes strep toxic shock syndrome? |
|
Definition
| streptococcus pyogenes toxemia |
|
|
Term
| How does strep TSS differ from staph TSS? |
|
Definition
| less frequent rash, more frequent bacteria in blood (bacteremia), |
|
|
Term
| What is the toxin for strep TSS? |
|
Definition
|
|
Term
| What can cause propionibacterium acne? |
|
Definition
| opportunistic pathogen, or acne |
|
|
Term
| How do you treat propionibacterium acne? |
|
Definition
| benzoyl peroxide, retin A, or blue light will kill it |
|
|
Term
| What it the gram stain for pseudomonas aeruginoas? |
|
Definition
| aerobic gram negative rod found in soil or water |
|
|
Term
| Can pseudomonas aeruginoas ferment? |
|
Definition
| no, they have to undergo oxidative respiration because they are strict aerobes |
|
|
Term
| What diseases does pseudomonas aeruginoas cause? |
|
Definition
| psuedomonas dermatitis, otitis externa |
|
|
Term
| What is pseudomonas dermatitis? |
|
Definition
| rash from swimming pool or hot tub (pseudomonas aeruginoas like it hot and dont mind chlorine) |
|
|
Term
|
Definition
| "swimmers ear" - infection of outer ear canal (outside of ear drum) by pseudomonas aeruginoas |
|
|
Term
| What is the epidemiology of pseudomonas aeruginoas? |
|
Definition
| opportunistic pathogen found everywhere, nosochomical infections, very natually antibiotic resistant |
|
|
Term
| why is pseudomonas aeruginoas natually antibiotic resistant? |
|
Definition
| because they spend their life in the dirt and organisms spew out antibiotics in the dirt so they learn to resist them before they are even exposed in a clinal situation |
|
|
Term
| What are the virulence factors of pseudomonas aeruginoas? |
|
Definition
| exotoxin A, dense biofilm in CF patients (leads to difficulty breathing) |
|
|
Term
| How do you diagnose pseudomonas aeruginoas? |
|
Definition
| culture on routine media (non-lactose fermentor, oxidase +) - they have grape like odor and some have pigments |
|
|
Term
| How do you treat pseudomonas aeruginoas? |
|
Definition
| usually will go away on their own, if not use antibiotics |
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