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Microbiology-Bacteria

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olesysha's version from 2016-08-23 12:45

Toxins

Question Answer
C. tetaniblocks release of glycine, GABA from inhibitory interneurons
C. botulinuminhibits ACh release from motor neuron at NM junction
V. choleraeActive A subunit ribosylates ADP--> activates adenylate cyclase -->inc. cAMP--> open CTFR channel and release Cl-->watery diarrhea /reduced absorption of Na and bicarbonate
E. coli heat labile toxinactivates adenylate cyclase --> increased NaCl secretion (watery diarrhea)
E. coli heat stable toxinactivates guanylate cyclase --> increased cGMP --> inhibits NaCl reabsorption (watery diarrhea)
S. dysenteriaeinactivates 60S ribosomal subunit --> inhibits protein synthesis --> kills intestinal epithelial cell (bloody, mucusy diarrhea)
EHEC, EIECinactivates 60S ribosomal subunit --> inhibits protein synthesis --> kills intestinal epithelial cell (bloody, mucusy diarrhea)
S. aureus enterotoxinfood poisoning (diarrhea + vomiting less than 24 hrs)
B. cereus enterotoxinfood poisoning (vomiting less than 24 hrs)
S. pyogenes pyrogenic toxinactivates endogenous IL-1 production (Scarlet fever)
S. aurerus pyrogenic toxinactivates endogenous IL-1 production (TSS)
S. pyogenestissue invasive toxins (hemolysin, streptokinase, DNAase...)
S. aureustissue invasive toxins (hemolysin, streptokinase, DNAase...)
C. perfringenshydrolyzes lecithin in cell membranes --> cell death (gas gangrene)
B. anthracis edema factorinserts an adenylate cyclase --> impairs PMN function + causes massive edema
B. anthracis lethal factorzinc metalloprotease --> induces macrophage to release TNF-alpha, IL-1 (death)
C. diphtheriaeribosylates elongation factor (EF2) --> inhibits protein translation (myocarditis, peripheral nerve palsies, CNS effects)
B. pertussisactivates membrane adenylate cyclase + inserts own adenylate cyclase --> inhibits PMN phagocytosis (cough)
C. difficilecytotoxic to colonic epithelial cells (bloody diarrhea, fever, abdominal pain)
P. aeruginosainhibits elongation factor (EF2) --> inhibits protein translation (targets liver)
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Classification

Question Answer
S. pyogenesgram+ coccus in chains; beta-hemolytic; bacitracin sensitive
S. agalactiaegram+ coccus; beta-hemolytic; bacitracin resistant
Enterococcusgram+ coccus; no hemolysis (normal colonic flora)
S. viridansgram+ coccus; alpha-hemolytic; optochin resistant; not bile soluble (normal oral flora)
S. pneumoniaegram+ coccus; alpha-hemolytic; optochin sensitive; bile soluble
S. aureusgram+ coccus in clusters; catalase +; coagulase +
S. epidermidisgram+ coccus in clusters; catalase +; coagulase -; novobiocin sensitive
S. saprophyticusgram+ coccus in clusters; catalase +; coagulase -; novobiocin resistant
B. anthracisgram+ rod; spore-forming; aerobic; non-motile
B. cereusgram+ rod; spore-forming; aerobic; motile
Clostridiumgram+ rod; spore-forming; anaerobic
Corynebacteriumgram+ rod; non spore-forming
Listeriagram+ rod; non spore-forming; tumbling motility
N. meningitisgram- coccus; maltose fermenter
N. gonorrhoaegram- coccus; matlose non-fermenter
H. influenzaegram- coccobacillus
Actinomycesgram+ rod; branching; has sulfur granules
Nocardiagram+ rod; branching; weakly acid fast
E. coligram- rod; fast lactose fermenter; motile
K. pneumoniaegram- rod; fast lacotse fermenter; non-motile
Proteusgram- rod; lactose non-fermenter; oxidase -
Shigellagram- rod; lactose non-fermenter; oxidase -; non-motile
Salmonellagram- rod; lactose non-fermenter; oxidase -; motile; produce H2S
V. choleraegram- comma-shaped rod; oxidase +
C. jejunigram- comma-shaped rod; oxidase +; grows at 42 degrees C
H. pylorigram- comma-shaped rod
Bacteroidesgram- rod; anaerobic; normal gut flora
Fusobacteriumgram- rod; anaerobic; normal oral flora
P. aeruginosagram- rod; aerobic; oxidase +
B. pertussisgram- coccobacillus
Legionellagram- rod; poorly-staining (use silver stain)
Chlamydiagram- rod; no peptidoglycan wall; obligate intracellular parasite
Rickettsiagram- rod; obligate intracellular parasite
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Presentation

Question Answer
S. pyogenes direct infectionpharyngitis, skin infection, scarlet fever, TSS
S. pyogenes antibody-mediated infectionrheumatic fever; glomerulonephritis
S. agalactiaeneonatal meningitis, pneumonia, sepsis
EnterococcusUTI
S. bovissubacute endocarditis
S. viridansdental caries, subacute bacterial endocarditis
S. pneumoniaepneumonia, meningitis (adults), sepsis
S. aureus toxin mediatedgastroenteritis, TSS, scalded skin syndrome
S. aureus direct invasion mediatedpneumonia, meningitis, osteomyelitis (children), acute endocarditis, septic arthritis, skin infection, sepsis, UTI
S. epidermidisprosthetic joint infection
S. saprophyticusUTI
B. anthracispainless black ulcer on skin; pulmonary hemorrhage; abdominal pain/ bloody diarrhea
B. cereusfood poisoning
C. botulinumcranial nerve palsies, muscle weakness, respiratory paralysis
C. tetanimuscle spasm, lockjaw, risus sardonicus, respiratory paralysis
C. perfringensgas gangrene
C. difficilepseudomembranous colitis
C. diphtheriaesore throat (pseudomembrane); myocarditis (AV block); peripheral nerve palsy, cranial neuropathies
Listerianeonatal meningitis, pneumonia, sepsis
N. meningitidismeningitis (teens), DIC, waterhouse-friderichsen syndrome
Actinomycesoral/ facial abscesses
Nocardiapneumonia in immunocompromised
N gonorrhoaeurethritis, PID, bacteremia (septic arthritis, rash); ophthalmia neonatorum (1st 5 days after birth)
Moraxella catarrhalisotitis media (children)
E. colineonatal meningitis; UTI; hospital acquired pneumonia/ sepsis; diarrhea
K. pneumoniaepneumonia (necrosis, bloody sputum common in alcoholics)
ProteusUTI, bladder stones
Shigellabloody diarrhea
Salmonella typhityphoid fever (fever, abd pain, hepatosplenomegaly, rose spots on abdomen); gastroenteritis; osteomyelitis (HbS patients)
Y. enterocoliticagastroenteritis
V. choleraesevere rice-water diarrhea (no pus)
C. jejunibloody diarrhea
H. pyloriduodenal ulcers; chronic gastritis
BacteroidesGI tract, pelvic, lung abscesses
Fusobacteriumnecrotizing pneumonia, periodontal abscess, abdominal abscess, otitis media
Pseudomonasburn infection, hot tub folliculitis, endocarditis, pneumonia, sepsis, malignant otitis externa, UTI, diabetic osteomyelitis
Burkholderiahospital acquired pneumonia (CF, chronic granulomatous disease)
Stenotrophomonashospital acquired pneumonia (respirator patients)
Acinetobacterhospital acquired pneumonia, UTI
H. influenzae type Bmeningitis (children), acute epiglottitis, septic arthritis (infants), sepsis, pneumonia
H. influenzae nontypeableotitis media, sinusitis
H. ducreyichancroid
Gardnerellabacterial vaginitis (fishy smell)
B. pertussislow grade fever, runny nose --> intense cough with whoop
Legionellapontiac fever (headache, myalgias, fatigue); legionnaire's disease (pneumonia, fever, cough)
Y. pestishot, swollen lymph nodes, high fever, conjunctivitis; sepsis, pneumonia (bubonic plague)
Francisellatularemia (ulceroglandular, pneumonia, oculoglandular)
Brucellaundulant fever
Pasteurellacellulitis
Borrelia recurrentisrecurrent fever
BartonellaCat scratch fever
Chlamydia trachomatis; types A-Cconjunctivitis, corneal scarring, blindness
Chlamydia trachomatis; types D-Kurethritis, cervicitis, PID, epididymitis, prostatitis
Chlamydia trachomatis; types L1-L3lymphogranuloma venereum
Chlamydia pneumoniaeatypical pneumonia
R. rickettsiifever, conjunctival injection, severe headache, rash (wrists, ankles --> generalized)
R. prowazekiiepidemic typhus (fever, headache, rash, delirium, extremity gangrene)
R. typhiendemic typhus (fever, headache, rash)
Coxiella burnetiiQ fever (headache, atypical pneumonia)
Borrelia burgdorferiLyme disease (erythema chronicum migrans --> Bell's palsy, peripheral neuropathy; heart block; arthritis --> chronic arthritis, encephalopathy)
Leptospiraflu-like symptoms; Weil's disease (renal failure, hepatitis-jaundice, hemorrhage)
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Virulence Factors

Question Answer
S. pyogenesM-protein (adherence, anti-phagocytic, antigenic); tissue invasive toxins
S. pneumoniaecapsule
S. epidermidisbiofilm
B. anthracisprotein capsule
Clostridiumspore
Bacillusspore
N. meningitidiscapsule, IgA protease, pili
N. gonorrhoaepili (antigenic variation); IgA protease
E. colipili, capsule (K-antigen)
K. pneumoniaecapsule
Proteusurease
Salmonellacapsule
Y. enterocoliticasurvives refrigeration
H. pyloriurease
H. influenzaecapsule, IgA protease
B. pertussiscapsule, pili
Chlamydia trachomatiselementary body (infective); reticulate body (reproductive)
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Treatment

Question Answer
S. saprophyticusvancomycin
MRSAvancomycin
B. cereusno treatment (toxin only)
C. botulinumantitoxin
C. tetaniantitoxin, vaccine
N. meningitidisvaccine; rifampin prophylxis in close contacts
H. pylorimetronidazole + bismuth + tetracycline/ amoxicillin
Bacteroidesmetronidazole, clindamycin
gardnerellametronidazole
Chlamydiadoxycycline (adults); erythromycin (children, pregnancy)
Rickettsiaedoxycycline
mycobacterium tuberculosisisoniazid, rifampin, ethambutol, pyrazinamide, streptomycin
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Culture Media

Question Answer
Corynebacteriumtellurite plate, Loeffler's media (methylene blue stain)
E. coliMacConkey's agar (pink); eosin-mthylene blue agar (blue-black)
N. gonorrhoeaeThayer-Martin media (Vancomycin, Polymyxin, Nystatin)
V. choleraealkaline media
C. jejunigrow media at 42 degrees C
H. influenzachocolate agar with factor V, factor X
B. pertussispotato agar
Legionellacharcoal-yeast extract with Fe, cysteine
M. tuberculosisLowenstein-Jensen agar
M. pneumoniaeEaton's agar
Fungisabouraud's agar
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Source

Question Answer
Legionellawater sources (A/C)
Y. pestisflea bite, rodents, prairie dogs
Y. entercoliticaunpasteurized milk
Francisellarabbits
Borrelia burgdorferiIxodes tick
Borrelia recurrentishuman body louse
Pasteurellacats, dogs
Bartonellacat scratch
Coxiella burnetiicattle, sheep, goats
Rickettsia rickettsiaetick
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