#Sketchy micro list skin

Organism vegetates and stays at wound site * Opisthotonus: exaggerated extension and arching of back due to spasms of back muscles ('OH-piece-thought-ton-nus') * Risus sardonicus: 'evil grin', or lock-jaw symptoms (jaw cannot open due to tense masseters) Spastic paralysis: relentless muscle contractions leading to rigidity (unlike flaccid paralysis seen in botulism) Streptokinase: converts plasminogen to plasmin, which is fibrinolytic -> can use to treat MI, strokeР”Р„SO (anti-streptolysin O) titer: check antibodies to detect recent strep infection: dx for RF or PSGNР”В¬lassically found in puncture wounds from rusty nails or barbed wire (closed off to air) Streptolysin O: lyse RBCs (we generate ASO antibodies)Р”Сћ. * Occurs 2 weeks after initial onset of strep infectionР”РЋ.

#Sketchy micro list skin

* Can occur after both pharyngitis and skin infections and NOT prevented by treatment * Damage from circulating Ab-Ag immune complexes that eventually deposit in the glomerulus Post streptococcal glomerular nephritis (PSGN) (type 3 hypersensitivity) *** Syndenham's chorea: involuntary mvmts, esp hand and faceР”Сћ. *** Erythema marginatum: pink rings on skin *** Subcutaneous nodules: most commonly on extensor surfaces of forearms, elbows, and knees *** Heart problems: valvular damage leading to new murmurs, myocarditis, pericarditis

* Symptoms categorized into 5 major criteria: JONES criteria * Develops after pharyngitis but NOT skin infections and ONLY if untreated * Damage to heart, esp valves (Mitral valve!!! e.g. * Molecular mimcry of mysoin in cardiac muscle: strong humoral response creates antibodies * Interferes with opsonization (anti-phagocytic) * M protein (cell wall): highly antigenic, main virulence factor Rheumatic fever (type 2 hypersensitivity): M protein-mimicry-mitral Other clinical (2): treated with penicillinР”РЋ. SpeA and SpeC: superantigen: scarlet fever, TSLS * Surgical emergency sometimes requiring amputation * Invades fascia underlying skin and spreads very rapidly Toxic shock-like syndrome (TSLS) mediated by superantigenР”Р€. * Strawberry tongue: reddening and swelling of the tongueР”Сћ. Streptococcal pyrogenic exotoxin (Spe) infections cause: (3) Strep throat/pharyngitis (red, erythematous, inflamed throat) PYR (pyrrolidonyl arylamidase) test positiveР”В®ncapsulated with hyaluronic acid (Hot Apple pie): also found in connective tissue of body -> not immunogenicР”В¬ellulitis and erysipelas (superficial cellulitis with well-demarcated borders this is the MOST common cause) Grow along single axis to form chains & pairs Methicillin sensitive: penicillins, esp Nafcillin ('Naf' for 'staph') MRSA: methicillin resistance via alteration of PBPs, which are responsible for building cell walls Rapid onset staph food poisoning form preformed toxin more vomiting than diarrhea (meats and mayonnaise) Toxin: TSST superantigen (nonspecific binding of MHC II of TCRs -> overactivation -> cytokine storm -> can be fatal) Toxic shock syndrome: leaving foreign packing in for too long e.g. Scalded skin syndrome: skin peeling off (exfoliative toxin - protease) boils, abscesses)Р”Р„cute bacterial endocarditis (IV drug users -> esp right sided infection affecting tricuspid) Skin infections (cellulitis, impetigo, furuncles/carbuncles i.e. Most common cause of septic arthritis and osteomyelitis in adults Protein A binds Fc portion of antibodies to prevent complement binding, thus inhibiting opsonization and phagocytosisР”В¬auses pneumonia with patchy infiltrates (esp post-viral!!!) Main virulence factor: protein A (component of cell wall) Mannitol fermenter: turns MSA plate from pink to yellow Ultimately inhibits protein synthesis and causes cell deathР”Р‡luoroquinolones (UTIs) and aminoglycosides (in combo with beta lactams)Р”В¬atalase positive (unlike Strep): H2O2 -> H2OР”В¬oagulase positive: specific for aureus (fibrinogen -> fibrin)Р”В«eta hemolytic (glowing halo of light in blood petri dish) Inactivates EF-2 (elongation factor 2) by ribosylation (bow and accordion) Most common G- cause of nosocomial pneumonia and pulmonary infection/respiratory failure in CF (cystic fibrosis) patients Nosocomial UTI (indwelling catheter infections) Osteomyelitis in IV drug users and diabetics Thrives in aquatic environments: under-chlorinated hot tub folliculitis (pruritic, papular, pustular)Р”В¬an cause sepsis -> toxins cause tissue damage and cutaneous necrosis with black lesions: erythema gangrenosum Produces blue-green pigment (pyocyanin and pyoverdin) Obligate aerobe (rest of Enterobacteriaceae are mostly facultative)Р”В¬atalase positive: risk for pts with CGD (chronic granulomatous disease) 2.1 - Bacillus anthracis and Bacillus cereusР”Р€ - Gram-Positive Branching Filamentous RodsР”Тђ - Gram-Negative Bacilli - Enteric tractР”В¦ - Gram-Negative Bacilli - Respiratory tract