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Micro bacteria 1

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felumore's version from 2016-02-16 17:25

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Question Answer
How to differentiate gram positive cocci?catalase test ; anaerobes do not have catalase
positive -- facultative anaerobes-- staphylococci,
negative -- anaerobes --> streptococci/ enterococci-
How to differentiate staphylococci into different types?Coagulase test;
-positive-- staphylococcus--bind fibrinogen to form fibrin
- negative -- Staphylococcus epidermidis, S. saoriohyticus
Yellow colonies in Mannitol Salt Agar, coagulase positiveStapylococcus aureus-- salt tolerant.
- mannitol salt Agar -S. aureus ferment mannitol--> yellow
novobiocin resistant coagulase negative cocciStaohylococci saprophyticus
--S. epidermidis - not resistant
Green colony in blood agar, catalase negative cocciStreptococci pneumoniae, Viridans streptococci
-- green in blood agar-- alpha hymolytic
Yellow colony in blood agar catalase negative cocciStreptococci pyogenes, Streptococci agalactiae
Yellow in blood agar--> beta hemolysis
Clear colony in blood agar, catalase negative.Enterococcus
non-hemolytic -
optochin susceptible, bile soluble diplococciStreptococci pneumoniae -
Optochin resistant, Bile resistant, gram positive, coagulase negative cocciStreptococci viridans , Streptococci mitis
Bacitracin susceptible Lancefield group A, gram positive, catalase negative cocciStreptococcus pyogene
PYR positive = pink
Lancefield group D antigen positive,
black precipitate on bile esculin agar
Enterococcus -
resistant to bile sale
clear on blood agar
Enterococcus faecalis, faeciumGram positive cocci catalase anaerobes- non hymolitic, normal GI
Aerobic, gram positive spore-forming rodsBacillus
Anaerobic, gram positive spore-forming rodsClostridium -
Gram positive - nonspore-forming rods, club-shaped
- black- browncolonies on tellurite agar
Corynebacterium
catalase positive -
Anaerobic, gram positive non spore forming rodsLactobacillus
Gram positive, nonspore forming rods, grows at low T, aerobicListeria -
Gram positive non spore forming rods, aerobic, acid fast, filamentous shapeNocardia-
Gram positive non spore forming rods , anaerobe, filamentous shapeActinomyces -
Gram negative diplococci,
Grow on Thayer-Martin agar ( chocolate agar w/ antibiotics) @ CO2 5%, kidney shape, oxidase positive, catalase positive, ferment glucose
- Neisseria gonorrheae ( ferment glucose)
- Neisseria meningitidis ( ferment glucose + maltose ) -
Gram negative cocobacilli
Aerobes, non fastidious , oxidase positive, catalase negative, easy growth on blood agar
Acinetobactor-
Gram negative cocobacilli- diplococcus
Aerobes, non fastidious , oxidase positive, catalase positive, non fastidious, blood agar, no fermentation
Moraxella-
Gram negative coco bacilli, Aerobes
fastidious, Bordet-Gengou, Regan- Lowe agar, NAAT used - 7-12 days incubation
Bordetella
Gram negative coco bacilli, Aerobes
nonfastidious, oxidase negative, BCYE chocolate agar, 3days incubation
Francisella
Gram negative coco bacilli, Aerobes
fastidious, oxidase positive, catalase positive, blood agar
Brucella-
Gram negative bacilli, aerobes, straight rods, oxidase positive, green pus, faculatative aerobes, no fermentationPseudomonas-
Gram negative bacilli, aerobes, straight rods, poor gram stain, Silver stain positive, direct fluorescent antibody test, BCYE agar, systeine, ironLegionella-
Gram negative bacilli, aerobes, curved, - gull wing oxidase positive, need less O2 tension, @ 42C*Campylobacter-
Gram negative bacilli, aerobes, comma-shaped, oxidase positive, alkaline environmentVibrio-
Gram negative bacilli, aerobes, Urease positive Oxidase positiveHelicobacter-
Gram negative bacilli, facultative anaerobes, oxidase positive coccobacilli, require factor X and factor V, need chocolate agarHaemophilus-
Gram negative bacilli, facultative anaerobes, oxidase positive, cocobacilli, bipolar stainingPasturella-
Gram negative bacilli, facultative anaerobes, oxidase negative, Ferment glucose, Lactose utilization ( pink in MacConkey agar -- positive, clear---negative)Enterobacteriaceae
Gram negative bacilli, facultative anaerobes, oxidase negative, lactose fermenting, produce H2SCitrobacter-
What is the test to determine Helicobacter?Urease test --- positive -
Gram negative bacilli, facultative anaerobes, oxidase negative, lactose fermentingenterobacter-
Gram negative bacilli, facultative anaerobes, oxidase negative, lactose fermenting, motilE Coli-
Which medium to use when finding if enterobacteriaceae is E scherichia Coli, or Shigella?MacConkey agar - pink - E.coli ( ferment lactose ) , pale, Shigella-
Gram negative bacilli, facultative anaerobes, oxidase negative, lactose fermenting, non-motil, encapsulatedKlebsiella pneumoniae-
Gram negative bacilli, facultative anaerobes, oxidase negative, non- lactose fermenting, make H2S, non motile, Hektoen enteric agar -greenShigella-
MacConkey -- clear
Gram negative bacilli, facultative anaerobes, oxidase negative, non- lactose fermenting, non- H2S producing, Bipolar staining, urease positiveYersinia pestis, enterocolitica-
Gram negative bacilli, facultative anaerobes, oxidase negative, non- lactose fermenting, H2S producing , cause of UTI, urease positive, swarming motilityProteus-
Gram negative bacilli, facultative anaerobes, oxidase negative, non- lactose fermenting, make H2S, motileSalmonella-
Hektoen enteric agar showed green , Oxidase test was negative, which bacilli?Shigella
-- green- non-lactose fermenting, no black dots--> non-H2S producing -
Hektoen enteric agar showed yellow- orange and black precipitate, which bacilli?Citrobacter -
yellow--> lactose fermenting, black--> make H2S
- Hekton inhinit gram positive
Which medium can determine pseudomonads?Cetrimide agar
--> green, bule yellow green -
How can you differentiate Salmonella and shigella?Hekton agar
Salmonella-- black precipitates -
What can be identified by urease test?Helicobacter, Proteus, Ureaplasma, Nocardia, cryptococcus -
positive= pink
Spirochetes, Gram negative cell wall, ThinTreponema-
Spirochetes, Gram negative cell wall, visible in blood smear, fastidiousBorrelia-
Spirochetes, Gram negative cell wall, hook obligate aerobe, grow @ 28-30 CLeptospira -
does not Gram stain, obligate intracellular,
have LPS, no PG, - reticulate body, elementary body
- within phagosome
Chlamydia, Chlamydophila- cannot make own ATP-
does not Gram stain, obligate intracellular, no PG, no LPS, giemsa stain, found in cytoplasmOrientia-
does not Gram stain, obligate intracellular, thin PG, Giemsa stain found in cytoplasmRickettsia-
does not Gram stain, obligate intracellular, no PG, no LPS, Giemsa or wright stain, in phagocytic vacuole, elementary bodies, reticulate bodiesEhrlichia, Anaplasma-
does not Gram stain, obligate intracellular, gram negative cell wall, - Acidophile, Small cell variant (Spore) , large cell variant, found in phagolysosomeCoxiella-
Mycoplasmasmallest bacteria require sterol, fried egg appearance -
Mycobacteiawaxy cell envelope, small, rods, need heat to stain -
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Question Answer
Bacterial structural toxinLPS, LOS, PG, lipoteichoic acid, lioiarabinomannan--- cause immune response -
what is endotoxin in gram negative cell wall?Lipid A -
antibiotic role on endotoxin relasebeta lactam target target penicillin binding protein --> cause release of LPS -
LPS released from lysed cell activate___macrophage- via CD14, TLR 4 --> also activate cytokine secretion
How PG fragments, lipoteichoic acid activate immune response?Bind to TLR 2,6 on macrophage--> cytokine relase -
Receptors that activate phagocytosis-mannose receptor, compleme - Fc receptors- --
blocked by capsules -- prevent phagocytosis
What is antigen responsible for serotyping?K antigen -
What is the role of streptococcus pyogene hyaluronic acid capsule on virulence?minic host cell-
Immune response to bacterial carbohydrateinnate- complement via lectin pathway,
humoral - T independent activation on B class switching -
quorum sensing in bioform formation-when cell density increase, it activate transcription factor for bioform
Effect of rifampicin on bioformnot effective, due to dormancy of bacteria -
super antigenbind MHCII and TCR cause T proliferation
-staphylococcal enterotoxin, TSST, streptococcal pyrogenic toxin
exotoxins that damages membrane- phospholipases,
Cperfringens alpha toxin
--> cause gas gangline
- surfactants -
Listeriolysin O -> escape form phagolysosome
what is AB toxin?intracellular exotoxin
A= active
B= binding to specific receptor
--> induce endocytosis
corynebacterium diphtheriae diphtheria toxin
Effectorsintracellular exotoxin
- use type III, IV secretion
-- produce inappropriate signals
-Salmonella Sip protein
How Botulinum toxin can cause either flaccid, or spastic paralysis.-Target different ganglions.
Neisseria meningigitidisGram negative, diplococcus, kidney bean shaped, Oxidase positive, calatase positive, non motile, type IV pili twitching, - NO LPS, has LOS
N. meningitidis diseasesepsis, meningitis - infant,
- via nasopharynx, respiratory transmission
-- initial petechiae rash, rapid progression to sepsis
Serous groups of Neisseria meningitidis-Based on O antigen -
A, B, C, Y, W-135 ( vaciccine target)
A-- related outbreak
virulence factor, neisseria meningitidis-- Pili - binding,
-- IgA protease- cleave IgA
--Adhesin,
--capsule - prevent phagocytosis,
--Neisserial porin,
-- PG - fragment cause immune response,
--LOS- exotoxin
How N. meningitidis act on hostlarge LOS release due to blebing--> cytokine release
Lipid A recognition by TCR 4, CD14 -
N. meningitidis diagnosisLumbar puncture, blood culture, Gram stain,
Pseudomonas AeruginosaGram negative bacillus, motile, oxidase negative, no fermentation,
green in fluorescent, fruity odor -
Pseudomonas Aeruginosa infectionImmunocompromised
skin, respiratory keratitis, otitis externa -
Pseudomonas Aeruginosa virulence factor-Adhesin--type IV pili
- LPS- endotoxin
- polysaccharide
- exotoxins -
Pseudomonas Aeruginosa--- exotoxin- Exotoxin A-- AB toxin, ADP ribosylate EF2 on diphthamide resideue -
Type III exotoxin---ExoS.T, U Y
---> Exo S; prevent DNA synthesis, Exo T; inhibit phagocytosis
-- phospholipase C
--phamnolipid-- surfactant
-- leukocidin
Pseudomonas Aeruginosa --exoenzymeElastase -- lung damages -cause chronic inflammation in CF
cyctic fibrosis-- prone to infection
-- cause bioform in CF lung
Pseudomonas Aeruginosa- biofilm formationadhesion -type IV pilli, flagella-
- make exopolysacchride; Pel, Psl
- Alginate in late biofilm
Straphylococcus aureusgram + clusters
Catalase +, coagulase +, beta hemolytic , yellow colonies, mannitol fermentation -salt tolerant,
--Penicillin resistance, pyogenic
-- normal flora,
Straphylococcus aureus - transmissionhand hygiene- respiratory, skin -
Straphylococcus aureus - virulence factorType 5, 8 capsule, bioform
cellulitis, toxic shock syndrome, scaled skin syndrome -
- adhesin -- clumping factor A, B
- Protien A- bind Fc of host/s Ig s
- Teichoic lipoteichoic acid
cytotoxin of Straphylococcus aureus- Alpha toxin -- pore forming
- beta toxin -- sphingomyelinase-- break membrane -
- gamma toxin,-- PVL - high affinity to leukocyte
- delta toxin
Straphylococcus aureus - food poisoningingestion of enterotoxin- SEA, SEB, SEC -
Straphylococcus aureus- toxic shockTSST1 - mestrual related -
Straphylococcus aureus- scalded skin syndromeSSSS -exfoliatin from bacteria degrade desmosomes--> baby -
Superantigen, organism, exotoxin, disease1) Staphylococcus aureus --- TSST1 ( enterotoxin F)---> Toxic shock , SEA, SEB, SEc.... --> food poisoning
2) Streptococcus pyogenes , pyrogentic toxin--> toxic shock, necrotizing fascitis
Cytolysins, organisms, exotoxin, disease1) Clostridium perfringen-- alpha toxin ---> gas gangline
2) Listeria monocytogens -- listeriolysin --> neonatal meningitis
3) pseudomonas aeruginosa--- phospholipase C
4) Straphylococcus aureus -- alpha toxin, beta toxin, gamma toxin, ---> abscesses
5) E coli-- alpha hemolysin --- UTI
AB toxin, organism, exotoxin, disease1) Clostidium, botulinum, AB, botulinum toxin
2) Clostridium tetani, tetanus neurotoxin--> tetanus
3) Corynebacterium diphtheriae -- diphtheria toxin--> diphtheria
4) Pseudomonas aeruginosa -- exotoxin A -via ADP tibosylation
5) vibro cholerae --- cholera toxin
6) E coli--- heat labile enterotoxin--> traveller's diarrhea, Vero toxin--> hemorrhagic colitis
Effectors ( injected toxins), organisms, exotoxin, diseased1) Salmonella -- Sip -- diarrheas
2) Pseudomonas aeruginosa -- ExoS, T, U -
3) H pylori -- Cag A -- ulcer
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