Micro Flashcards
Ventilator-associated pneumonia
pseudomonas aeruginosa
septic arthritis in young adult
neisseria gonorrhoeae
Waterhouse-Freidrichsen Syndrome
neisseria meningitidis
Cellulitis
S. aureus or S. pyogenes
Scalded Skin Syndrome
S. aureus (exfoliative toxin)
Gray-white membrane in the posterior pharynx of an unvaccinated child
C. diptheriae
Most common cause of meningitis
S. pneumoniae
Most common cause of osteomyelitis
S. aureus
Serious newborn infection
Listeria, E. coli, Group B Strep
Infant w/ poor muscle tone
C. botulinum
Diarrhea after ABX use
C. difficile
Respiratory distress in a postal worker
B. anthracis
Otitis media in children
S. pneumo
Spore formers
Clostridium, Bacillus, Coxiella burnetti
Tx of C. difficile colitis
Metronidazole or ORAL Vancomycin
GPR branching filmentous w/ sulfur granules
Actinomyces israelii
Rheumatic Fever
S. pyogenes
Subacute Endocarditis
Viridans Group Strep, Enterococci, S. bovis, coag (-) Staph, HACEK organisms
GI Sx after eating potato salad
S. aureus
GI Sx after eating reheated rice
B. cereus
Infections of indwelling foreign devices
S. epidermidis
Red pigment producer
Serratia marcescans
Blue-Green pigment producer
P. aeruginosa
Gold pigment producer
S. aureus
Yellow (sulfur) pigment producer
Actinomyces israelii
Dental procedure ->
Viridans Group Strep
Dental caries
S. mutans
Lipoteichoic acid
Capsule of G(+) induces TNF-alpha & IL-1
Acute Phase Cytokines
IL-1, IL-6, TNF-alpha
Fimbriae
mediates adherence
Pilus
Sexual conjugation (DNA transfer)
Capsule
elusion of phagocytosis
Quellung Reaction
capsule (+) –> swelling (+ anti-capsule serum)
Encapsulated bacteria
E. coli *S. pneumoniae Pseudomonas aeruginosa *Neisseria meningitidis Klebsiella pneumoniae *Haemophilus influenzae type B Salmonella typhi Group B Streptococcus
Meningitis in AIDS pts
Cryptococcus neoformans
Recombinant bacteria is made via
Transformation (DNA released by lysed cell -> picked up by another bacterium & incorporated in chromosomal DNA)
Transduction
phage infects bacterium (dirty - may pick up other DNA fragments)
Doesn’t Gram stain d/t high sterol composition & no cell wall
Mycoplasma
Doesn’t Gram stain d/t high Mycolic Acid composition
Mycobacteria
Spore-formers
Bacillus, Clostridium
Dark-Field Microscopy
Treponema
Atypical pneumonia d.t broken Air conditioner
Legionella pneumophila
PAS stain
Whipple Disease Dx (Tropheryma whipplei)
Ziehl-Neelson Stain (Carbolfuchsin AKA Acid-Fast)
Mycobacterium, Nocardia
India Ink Stain
Cryptococcus neoformans
Silver Stain
Pneumocystis jiroveci, Legionella pneumophila, Helicobacter pylori
Giemsa Stain
Chlamydia, Borrelia, Rickettsiae, Plasmodium, Trypanosomes, Histoplasma
Lipid A
G(-) outer membrane component that induces TNF-alpha & IL-1
Endotoxin
G(-) LPS
Transpeptidase
enzyme that cross-links the peptidoglycan layer of the cell wall
“O” antigen
LPS/Lipid A of G(-) Outer Membrane
Periplasm contains
b-lactamases
“H” antigen
Flagella
“K” antigen
Capsule
Capsule containing D-glutamate
B. anthracis
PAS stains which moclecules
glycogen & mucopolysaccharides
Chocolate agar + factors 5 (NAD+) & 10 (hematin)
Haemophilus influenzae
Thayer-Martin (or VPN) agar
Neisseria spp.
Charcoal yeast medium w/ Fe & cysteine
Legionella
Sabouraud agar
Fungi
pneumonia in Cystic Fibrosis pts
Pseudomonas aeruginosa
Anaerobes lack
catalase &/or dismutase -> oxidative damage
Which ABX is ineffective against anaerobes?
AminO2glycosides :)
Common ABX for anaerobic infections
Metronidazole or Clindamycin
Ventilator-associated pneumonia
Pseudomonas aeruginosa
Gamma hemolysis
Enterococcus
Beta Hemolysis
Group A Strep (S. pyogenes)
Group B Strep (S. agalactiae)
Alpha Hemolysis
Strep Viridans Group
S. pneumoniae
Endocarditis w/ _______________ warrants evaluation for Colon Cancer
S. bovis
Impetigo
S. aureus
What type of pt is at risk for severe infections by encapsulated bacteria?
Asplenics (opsonization is required for clearing infection)
People w/ Chronic Granulomatous Disease have recurrent infections w/ ______________ d/t a deficiency of ____________
Catalase (+) organisms;
NADPH oxidase deficiency
Facultative Intracellular organisms
Salmonella Neisseria Brucella Mycobacterium Listeria Francisella Legionella Yersinia pestis
Obligate Aerobes
Nocardia
Pseudomonas aeruginosa
MycoBacterium tuberculosis
Gram Stain Limitations
Treponema -> Dark-Field Mycoplasma -> no cell wall Mycobacterium -> Acid-Fast Legionella pneumophila -> Silver stain Rickettsia -> Giemsa stain Chlamydia -> Giemsa stain
GNR Lactose Fermenters
Citrobacter – Fast Lactose Fermenter Klebsiella – Slow Lactose Fermenter E. coli - Slow Lactose Fermenter Enterobacter - Slow Lactose Fermenter Serratia - Fast Lactose Fermenter
Catalase (+) organisms
Pseudomonas Listeria Aspergillus Candida E. coli S. aureus Serratia
Catalase (+) organisms
Pseudomonas Listeria Aspergillus Candida E. coli S. aureus Serratia
Urease (+) organisms
Cryptococcus H. pylori Proteus Ureaplasma Nocardia Klebsiella S. epidermidis S. saprophyticus
Protein A is expressed by _________ & has what MOA
S. aureus;
binds Fc of IgG to prevent opsonization & phagocytosis
What structure protects against phagocytosis?
capsule
Plasmids are exchanged by?
Conjugation
Superantigen MOA
bind MHC class II -> activate TCR -> polyclonal T-cell expansion -> huge release of cytokines
What organisms secrete superantigens?
S. aureus & S. pyogenes
Diptheria toxin MOA
inactivates EF-2 -> cell death
Pseudomonas aeruginosa toxin
Exotoxin A
Exotoxin A of Pseudomonas aeruginosa MOA
inactivates EF-2 -> cell death
Shiga toxin MOA
cleaves host rRNA at Adenine base in 60S subunit -> prevents protein synthesis -> cell death
Shiga Toxin is expressed by
EHEC 0157:H7 & Shigella
Hemolytic Uremic Syndrome Sx
thrombocytopenia, hemolytic anemia, acute renal failure
HUS is caused by what organism
EHEC 0157:H7
ETEC heat-labile toxin MOA
activates adenylate cyclase -> increase cAMP
ETEC heat-stabile toxin MOA
activates guanine cyclase -> increase cGMP
Pseudoappendicitis
Yersinia enterocolitica
Anthrax toxin
3 components:
- Edema Factor (activates a.c. -> increase cAMP)
- Lethal Factor
- Protective Factor
Diptheria toxin MOA
inactivates EF-2
Heat-stabile toxin MOA; expressed by?
activates guanine cyclase -> increase cGMP;
ETEC & Yersinia entercolitica
Anthrax toxin
3 components:
- Edema Factor (activates a.c. -> increase cAMP)
- Lethal Factor
- Protective Factor
Traveler’s Diarrhea
E. coli
TSST-1 MOA
(S. aureus) causes release of cytokines -> TSS
“rice water” stools
Vibrio cholera
Botulinum toxin MOA
inhibits ACh release at NMJ -> flaccid paralysis
Tetanospasm toxin MOA
blocks release of GABA/glycine inhibitory NTs from Renshaw cells -> muscle contraction
Cholera toxin MOA
activates a.c. -> increase cAMP
Pertussis toxin MOA
inactivates the inhibitor of adenylate cyclase -> increase cAMP
Phospholipase causing gas gangrene (organism/toxin?)
C. perfringens - alpha toxin
Panton-Valentine Leukocidin MOA (organism?)
S. aureus - tissue destruction w/ MRSA, killing macrophages & neutrophils
Exfoliative toxin MOA (organism?)
S. aureus - disrupts zona granulosa -> flaccid bullae -> Scalded Skin Syndrome (newborns)
Woman on period using super-absorbent tampon–>
Toxic Shock Syndrome d/t S. aureus & TSST-1
Streptolysin O
S. pyogenes - O2-labile -> hemolysis
Streptolysin S
S. pyogenes - O2-stabile -> hemolysis
Scarlet Fever
S. pyogenes - pyrogenic exotoxins (A, B, C)
Biofilm production is esp pronounced in
S. epidermidis
IgA protease producers
(SHiN)
S. pneumo
HiB
Neisseria
M protein is produced by ______________ and has what MOA?
S. pyogenes;
helps prevents phagocytosis
Bull Neck
C. diptheriae
HUS is caused by what organism
EHEC 0157:H7 & Shigella
ETEC heat-labile toxin MOA
activates adenylate cyclase -> increase cAMP
-> increased Cl- secretion in GIT
Heat-stabile toxin MOA; expressed by?
activates guanine cyclase -> increase cGMP -> decreased NaCl resorption in GIT;
ETEC & Yersinia entercolitica
Botulinum toxin MOA
inhibits ACh release at NMJ (cleaves SNARE protein) -> flaccid paralysis
Tetanospasm toxin MOA
blocks release of GABA/glycine inhibitory NTs from Renshaw cells (cleaves SNARE protein) -> muscle contraction
Pertussis toxin MOA
inactivates the (Gi) inhibitor of adenylate cyclase -> increase cAMP
Bull Neck (severe LAD)
C. diptheriae
Painless black eschar
Cutaneous Bacillus Anthracis
Whooping cough
Bordetella pertussis
Impetigo
S. aureus & S. pyogenes
Superantigen MOA
bind MHC class II -> activate TCR -> polyclonal T-cell expansion -> huge release of IFN-gamma & IL-2
Diptheria toxin MOA
inactivates EF-2 (ADP ribosylator)
Whooping cough
Bordetella pertussis
“double zone” of hemolysis on blood agar
C. perfringens
ASO
(anti-Streptolysin O Ab) used to diagnose Rheumatic Fever (S. pyogenes)
LPS/Endotoxin activates (6)
- > macrophages ->TNF-alpha, IL-1, NO
- > complement -> C3a, C5a
- > tissue factor -> Coag cascade -> DIC
“rust-colored” sputum & lobar pneumonia
S. pneumoniae
Otitis Media
S. pneumoniae
Bacterial Toxins encoded by Lysogenic Phages
shigA toxin Botulinum toxin Cholera toxin Diptheria toxin Erythrogenic toxin of S. pyogenes
Organism associated w/ Acute Post-Strep Glomerulonephritis
S. pyogenes
Mediastinal widening
Bacillus anthracis (Inhalation Anthrax)
Which Streptococcus strain is susceptible to Optochin?
S. pneumo
Which Streptococcus strain is resistant to Optochin?
Viridans group
Cervicofacial Disease w/ draining sinus tracts
Actinomyces israelii
Contaminant of deli meats & unpasteurized milk products
Listeria
Obligate Anaerobes
Clostridium
Bacteroides
Actinomyces
Superantigen
TSST-1 (S. aureus) Exotoxin A (S. pyogenes)
Superantigen
TSST-1 (S. aureus) Exotoxin A (S. pyogenes)
2nd most common cause of UTI in young women
S. saprophyticus
Novobiocin Resistance
S. saprophyticus
Novobiocin Sensitivity
S. epidermidis
Sepsis in Sickle Cell pts or Asplenics
S. pneumoniae
S. pneumo is the MOST COMMON CAUSE OF
Meningitis
Otitis Media
Pneumonia
Sinusitis
MOST common cause of osteomyelitis
S. aureus
“Thumb Sign” on X-ray
Epiglottitis (H. influenzae type B)
Neonatal conjunctivitis
N. gonorrhoaea
Meningitis in young adults & children
N. meningitidis
Purpura Fulminans
N. meningitidis
Pontiac Fever
Legionella pneumophila
Hot Tub Folliculitis
P. aeruginosa
Burn victim wound infection
P. aeruginosa
GN diplococci, Oxidase (+) organism in COPD sputum sample
Moraxella catarrhalis
Diarrhea 1-3d following handling turtles
Salmonella
Osteomyelitis in a Sickle Cell pt
Salmonella
42C Culture
Campylobacter
Common cause of gastroenteritis & Guillain-Barre Syndrome
Campylobacter
Pneumonia in Alcoholics or COPD pts
Klebsiella pneumoniae
“Currant-jelly” sputum
Klebsiella pneumoniae
“Swarming” motility
Proteus
Struvite stones -> Staghorn Calculi
Proteus
E. coli causing HUS
EHEC O157:H7
Diarrhea d/t GN, non-motile, lactose nonfermenter
Shigella
Diarrhea d/t “S-shaped” organisms
Campylobacter jejuni
Diarrhea from household pets
Yersinia enterocolitica or Salmonella
Diarrhea d/t GN, motile, lactose nonfermenter
Salmonella
Traveler’s Diarrhea
ETEC
Diarrhea from undercooked hamburger meat
EHEC
Diarrhea mimicking appendicitis
Yersinia
Diarrhea after handling raw chicken or eggs
Salmonella or Campylobacter
Osteomyelitis in Sickle Cell pts
Salmonella
Osteomyelitis in Sickle Cell pts
Salmonella
“Comma” shaped GNR
Vibrio
“S” shaped GNR
Campylobacter
Which E. coli invades the intestinal wall?
EIEC
Infection caused by animal urine?
Leptospira (water contaminated w/ urine)
Hantavirus (rodent urine)
“Target” shaped lesion is associated w/ what disease
Lyme’s Disease
Lyme’s Disease is transmitted by what vector
Ixodes tick
Lyme’s Disease is caused by what organisms
Borrelia burgdorferi
B/L facial n. palsy
Lyme’s Disease (disseminated)
Causes of rashes on palms & soles
Kawasaki Disease
Coxsackie A
Rocky Mountain Spotted Fever
Secondary Syphilis
External Otitis (Swimmer’s Ear)
Pseudomonas aeruginosa
Ecthyma Gangrenosum in immunocompromised
Pseudomonas aeruginosa
What allows S. sanguinis to bind to damaged heart valves?
Dextrans -> bind fibrin-platelet aggregates on damaged heart valves
S. pyogenes pyrogenic conditions
pharyngitis, cellulitis, impetigo
S. pyogenes toxigenic conditions
Scarlet fever, TSS-like, necrotizing fasciitis
S. pyogenes Immunologic conditions
Rheumatic Fever & Acute Post-Strep Glomerulonephritis
Ab to what S. progenies virulence factor gives rise to Rheumatic Fever?
Antibodies to M protein
Ab to what S. progenies virulence factor is used in the Dx of Rheumatic Fever?
Anti-Streptolysin Antibodies (ASO) - confirms prior S. pyogenes infection
“Strawberry tongue”
Scarlet fever d/t S. pyogenes
“Sandpaper-like” Rash
Scarlet fever d/t S. pyogenes
CAMP test or Hippurate Test is an important diagnostic test for?
S. agalactiae
Important cause of Biliary Tract Infections & UTIs?
Enterococci