Gram Pos Cocci Flashcards

Question

S. lug pathogenicity

Answer 1

-Resembles S. aureus -> skin infections / abscesses (below the waist!!) -Endocarditis (native and prosthetic) -FBRIs

Answer 2

-Recurrent UTIs in sexually active women -2nd most common behind E. coli for uUTI -NovobiocinR

Answer 3

mecA / mecC

Answer 4

1) Slide test 2) Tube test -> rabbit plasma 37C 4 hrs, if neg, 18 hrs False neg if: staphylokinase+, SCV

Answer 5

-Presumptive ID -Detection of ProteinA, Clumping FactorA, Capsular polysccharides False pos: S. haemo, S. hominis that have type 8 capsular polysacc. or S. sapro w/ cell wall hemmagglutinin

Answer 6

PenR = 75-80% S. aureus / S epi mecA / mecC = R to all pen, ceph, and carbs -cefoxitin / oxacillin R = methicillin R -cefoxitin better surrogate b/c oxacillin requires 2% NaCl w/ 24 hr incubation at no more than 35C --exception = S. pseudintermedius -oxacillin has different breakpoints for different Staph species VISA / VRSA = cell wall alterations (petidoglycan mod) from vanA

Answer 7

-2 pos blood cultures for the same species w/in 5 days OR 1 pos blood culture plus clinical evidence of infection -Same species on intravenous cath tip and blood culture

Answer 8

-Cat- -GPC in chains -Intra/interspecies difference due to carbs, surface proteins, teichoic acid -Facultative anaerobes -NO respiratory metabolism b/c no heme -> only fermentative -Adding glucose etc to medium enhances growth but quickly changes pH and then inhibits

Answer 9

-Commensals on mucous membranes -Sometimes transient skin -S. pneumo carriage rate = 30-70% in kids; <5% in adults -GAS carriage rate = 5% of adults -GBS carriage rate = 10-30%

Answer 10

-Most common cause of bacterial pharyngitis (15-30% children/5-10% adults) and impetigo -Scarlet fever (erythematous sandpaper-like rash) -STSS (most often seen if: young child or elderly, diabetes, skin breakdown, cardiac/pulmonary disease, HIV, IV use) -Glomerulonephritis after skin or throat infections -> antibody-mediated inflammatory disease -> puffy face, tea-colored urine -PANDAS -Necrotizing fasciitis (>50% mortality rate) [Fournier's gangrene -> male genitalia] -Rheumatic fever after pharyngitis (antibodies cross-react w/ heart) = fever, myocarditis, arthritis, chorea (uncontrolled dance-like movements), subcutaneous nodules, rash (erythema marginatum)

Answer 11

Lancefield antigen

Answer 12

-80 different types -Inhibits complement -> protects from phagocytosis -Typing used for STSS (M1/M3)

Answer 13

-Oxygen labile -Destroys RBCs and WBCs -Antigenic - can order Ab titres against ASO (maximum titre at 3-6 weeks post-infection)

Answer 14

-Oxygen stabile -Destroys RBS -NOT antigenic

Answer 15

-Scarlet fever -SUPERANTIGEN -STSS -> superstimulate T cells -> cytokines

Answer 16

Break down stuff -Antigen testing against DNaseB (maximum titre 6-8 weeks post-infection)

Answer 17

1) Neonatal sepsis / pneumonia (birth to 7 days) 2) Neonatal meningitis (7 days to 3 months) -> postnatal transmission -> NO stiff neck, instead fever, vomiting, poor feeding, irritability 3) Invasive infection in adults -> elderly, immunocompromised, diabetes, cancer, alcoholism

Answer 18

1) Similar to GAS except no scarlet fever

Answer 19

1) CA-pneumonia (81-87% of cases) 2) Sepsis 3) Meningitis (usually secondary to pneumonia/ear infection) 4) Ear infections (60% of kids < 3 will have an S pneumo ear infection) 5) Sinusitis 6) Peritonitis 7) Endocarditis (rare)

Answer 20

-Protect from phagocytosis -Antigenic -84!!! different serotypes -Urine antigen detection is against C-polysaccharide antigen -Bile soluble

Answer 21

-Oral cavity, GI tract, vaginal tract commensals -Transient on skin -Infection of native valves / prosthetic valves (less frequent) -Sepsis after chemo -Increase in PenR

Answer 22

-Oral cavity, GI tract, urogenital commensals -Abscess formation in brain (S. intermedius), oropharynx, peritoneal cavity -Respiratory infection in cystic fibrosis patients (S. constellatus) -Variable hemolysis (can be any) -Small

Answer 23

-Oral cavity and blood -Bacteremia, endocarditis, meningitis -S. sal in blood may = neoplasia -Non or alpha -Sucrose-containing agar = large mucoid or hard colonies

Answer 24

-Oral cavity -> dental carries -Bacteremia -Produces extracellular polysaccharide from glucose -Hard, adherent, alpha colonies but can be beta in anaerobic conditions -Sucrose-containing agar = rough frosted glass, heaped colonies surround by liquid

Answer 25

-Bacteremia, sepsis, endocarditis -S. gallolyticus sub gallolyticus = endocarditis and colon cancer/chronic liver disease -S. gallolyticus sub pasteurianus = infant meningitis -Non-enterococcal group D, PYR- -Grow on bile esculin but not in 6.5% NaCl -Non or alpha -Can't ferment sorb

Answer 26

-Lose viability quickly -Need moist transport medium except for GAS

Answer 27

-Against C-polysaccharide antigen -Pos 1-6 months post-infection -BUT also detects carrier states so not useful in children < 6

Answer 28

-BAP b/c hemolytic reaction -> growth enhance by external catalase source -35-37C, 5% CO2 or ana conditions enhance growth -S. pneumo / VirStr need 5% CO2 (8% won't grow in ambient air)

Answer 29

1) GAS = large hemolysis and PYR+, bacitracinS 2) GBS = soft hemolysis under colony and PYR- and CAMP+ (B is a hipp-ocrit -> hippurate +) 3) S. anginosus = ppt colonies, caramel/butterscotch odor (due to production of diacetyl), VP+

Answer 30

-35 - 37 weeks of pregnancy -Vaginal / rectal swab -Transport media (Amies or Stuarts) -> viable up to 4 days at RT or refrigerated -Selective broth -> nalidixic acid + gent or nalidixic acid + colistin

Answer 31

-GAS = PenS -GBS = PBP2x PenR --29% clindamycinR --49.5% erythR -Increasing fluoroquinolone resistance -> do not use as first-line

Answer 32

-PenR at higher frequency -Treatment options: Ceph, Macrolides, Fluoro, Vanc -Increasing fluoroR due to mutations in parC (DNA topoisomerase IV) and gyrA -Different B-lactam breakpoints for CSF vs. non-CSF

Answer 33

-Gram+ -Cat- (can be weak+) -Usually non/alpha-hemolytic but E. faecalis can be beta -Facultative anaerobe -Lactic acid bacteria (lactic acid is end product of fermentation) -Grow in 6.5% NaCl -Bile esculin + (can grow in 40%) -PYR+ -LAP+ -D Lancefield group

Answer 34

-GI tract (they love bile) -Can also be on skin (peritoneum), genitourinary tract, or oral cavity -Super hardy bugs - can tolerate heat, alcohol, and chlorine -> NOSOCOMIAL INFECTIONS

Answer 35

1) Nosocomial infections -> from GI tract to other sites 2) UTIs 3) Wounds 4) Valve endocarditis (native and prosthetic) 5) Bacteremia / sepsis 6) Implants / catheters HIGH RISK: Elderly, immunocompromised, long hospital stay, indwelling devices, recent broad-spectrum antibiotic treatment 2nd or 3rd leading cause of UTIs, wounds, and bacteremia

Answer 36

1) Surface adhesin Esp 2) Aggregation substance 3) Secreted cytolysin / hemolysin 4) Secreted protein gelatinase / serine protease 5) Extracellular superoxide 6) Ace -> MSCRAMM (microbial surface components recognizing adhesive matrix molecule) -> adhesin to collagen 7) Capsule and polysaccharide = can make biofilms 8) EfaA -> E. faecalis antigen

Answer 37

Large genetic islands or plasmids -> peptidoglycan synthesis pathway alteration to decrease binding affinity - D-Ala-D-Ala -> D-Ala-D-Lac

Answer 38

Was 90%/10% but E. faecium is increasing now

Answer 39

-Agar containing blood -Don't require CO2

Answer 40

-Needed for hospital surveillance / epidemiology - Enrichment broth: --BHI broth vancomycin concentrations varying from 3 to 30 mg/ml --Bile Esculin-azide broth supplemented with vancomycin at concentrations of 4 to 15 mg/ml (black = Enterococcus -> fast screening tool) --Enterococcosel broth medium supplemented with concentrations of vancomycin varying from 4 to 64 mg/ml --6 mg/ml is most common Vanc conc

Answer 41

- Intrinsically resistant to B-lactams and aminoglycosides - Treated with combo agents (synergistic) --B-lactam + aminoglycoside OR --Vanc + aminoglycoside - Acquired R to multiple classes due to genetic islands - Pen can predict Amp/others but Amp can't predict Pen - Amp predicts other -cillins (E. faecalis / faecium) and Imp (E. faecalis)

Answer 42

- VanA: inducible HLR to vancomycin as well as to teicoplanin - VanB: variable (moderate to high) levels of inducible resistance to vancomycin only - VanC: low-level resistance to Vanc

Answer 43

Bullous impetigo -large pustules w/ small zone of erythema Cellulitis without large area of necrosis

Answer 44

Ritter Disease Exfoliative toxin from phage2 -lesion->cutaneous erythema->skin peeling -toxin excreted from kidneys -2-4 days after onset -starts at face, neck, axilla, groin -> trunk, extremities

Answer 45

Initiates from tampons, after flu, after surgery -localized infection by systemic toxin -fever, rash, GI symptoms-> hypotensive shock

Answer 46

Toxic Epidermal Necrolysis -Drug-induced hypersensitivity rxn

Answer 47

From ingesting toxin Symptoms start 2-8 hours after ingestion and last 24-48 hours

Answer 48

1) erysipelas = raised red rash 2) Pyoderma = pustule 3) Necrotizing fasciitis (TYPE II)

Answer 49

GAS rash trunk & neck -> extremities (NOT face) -Strep Pyrogenic Exotoxin (Spe)

Answer 50

Caused by SpeA Superantigen

Answer 51

-only after untreated GAS pharyngitis -fever, myocarditis, arthritis, uncontrolled movements (chorea), subcutaneous nodules, rash -antigen-antibody cross-reaction in heart

Answer 52

-~1 week after GAS infection (pharyngitis or skin) -Ig-Ag complexes get stuck in kidneys -Puffy face, dark urine

Answer 53

-#1 cause of pneumonia in adults -lobar pneumonia -> chills, dyspnea, cough -lung full of WBCs, bacteria, exudate -high mortality (10% treated, 50% untreated)

Answer 54

Enterococcus! -UTI -Wound infections -Prosthetic valve endocarditis -Bacteremia / sepsis

Answer 55

-if found in blood, high likelihood of colon cancer

Answer 56

-opportunistic pathogen -bacteremia -endocarditis -UTIs -look like virstrep on culture but staph on gram stain

Answer 57

-colonies like virstrep but decolorize to look like GNC in gram stain -Endocarditis, wounds, abscesses

Answer 58

S. anginosus group

Answer 59

S. pneumoniae