Glossary of MMG 552 Final Exam

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Corynebacterium diphtheria
Gram +
Catalase +

Diptheria toxin: must have B-tox phage to cause disease

*Localized destruction of epithelium* - Do not invade cells (transmission is aerosol and fomites)- inflammatory response - pseudomembrane formation - systemic toxemia

Clostridium tetani
Gram + rods

Tetanus toxin: non-transmissible plasmid

Injection of spores into deep wound --> spastic paralysis

*Prevents release of inhibitory NTs at NMJ = lockjaw, stiff neck, stiff back .. respiratory failure

Low ID50 and does not invade cells

Tx with antitoxin HTIG

Clostridium botulinum
Gram + rods

Botulinum toxin: encoded on bacteriophage

No person to person transmission

Flaccid paralysis - *prevents ACH release, inhibiting muscle contraction

- double/blurred vision, drooping eyelids, slurred speech, muscle weakness, NO fever

Vibrio cholerae
Gram - curved rod
Faculative anaerobe
Highly motile
Oxidase +

Cholera toxin: encoded on lysogenic CTX macrophage bacteriophage - increases cAMP

Type II secretion - ToxR

Oral-fecal transmission, explosive watery diarrhea (rice water stools)

*Must ingest organism to cause disease**

No inflammation

Staphylococcus aureus
Gram + cocci
Faculative anaerobe
Catalase +
Coagulase +

Protein A (prevents opsonization by Ab)

Toxic shock syndrome (toxin w/o bacteremia!), scalded skin syndrome, food poisoning, systemic infections

Streptococcus pyogenes
Gram + rods
Faculative anaerobe
Bacitracin sensitive
Catalase -

Scarlet fever, toxic shock-like syndrome (SpeA production.. there IS bacteremia), necrotizing fasciitis, rheumatic fever, glomerulonephritis

Streptococcus pneumonia
Gram + pneumococci
Faculative anaerobe
Catalase -
Bacitracin sensitive
Optochin sensitive

Reservoir: URT Transmission: aerosol

Pneumolysin slows ciliar beating, activates C' pathway, inactivates ox burst
**polysaccharide capusle is required for virulence**

Legionella pneumophila
Gram - rod
Obligate aerobe
Faculative intracellular (multiple in macrophages!, requires Dot and Icm proteins)
Catalase +

Legionnaire's disease (mortality), pontiac fever

PCN not effective

Mycobacterium tuberculosis
Acid fast rods
Obligate aerobe
Faculative intracellular (multiply in unactivated macrophages)

Does NOT produce exo- or endotoxins

Tuberculin hypersensitivity, primary TB, miliary TB PPD-, latency PPD+, Reactivation TB/secondary TB

Treponema pallidum
Gram - like
corkscrew motile

No known toxins!

Primary, secondary, and tertiary syphilis (also congenital)

Neurosyphilis = irreversible

Difficult to culture!

Borrelia burgdorferi
Gram - like
corkscrew motile

Fe abstinence!

Lyme disease
- initial phase: erythema migrans (bulls eye rash)

OspA - anchors tick; OspC - target salivary gland; OspE - inhibits C' pathway

Chlamydia trachomatis
Gram - like
No Pg
Don't synthesize AA
Obligate inracellular

*Can't gram stain because too small!*

RB - reticulate body: fragile, replicative form.. produce ATP by ox phos
EB - type III secretion! (EBs at the center.. excit of EBs by vacuole lysis or fusion w/ new host)

Neisseria gonorrhoeae
Gram - diplococci
Faculative anaerobes
Faculative intracellular (non-ciliated epithelial cells)
Oxidase +
Catalse +

LOS --> primary toxin causing damage

Disseminated gonococcal infection --> Tbp allows acquisition of Fe, LOS variants protect from C' pathway, gonococcal arthritis

Purulent exudates

Neisseria meningitidis
Gram - diplococci
Faculative anaerobes
Faculative intracellular (non-ciliated epithelial cells)
Oxidase +
Catalase +

*transient normal flora* asymptomatic carriers

Transmission: respiratory aerosis!

Meningitis, meningococcal septicemia, LOS, disseminated intravascular coagulation (DIC) --> severe endotoxic shock.. 100% mortality without treatment

Enterobacteriaceae ..common themes
Gram -
non-spore forming
faculative anaerobic
Oxidase -
Survive in bile salts

Types: shigella dysenteriae, salmonella typhi, salmonella enteritidis, E. coli

O-Ag --> LPS
K-Ag --> capsule
H-Ag --> flagellin

Shigella dysenteriae
Ferments glucose, NOT lactose
Doesn't produce H2S

Culture on Triple sugar iron agar = yellow butt, red slant

Type III secretion, decreases Na+ reabsorption, increases luminal fluid, cell death

3 phases:
1. uptake by "trigger" and "membrane" mechanisms
2. escapes phagosome
3. spreads to 2nd cell by polymerized actin tails

Low ID50

Salmonella typhi
Ferments glucose, not lactose
Produce H2S

LPS. Survival in vacuoles of macrophages


Culture on TSI agar = black

Self-limiting, antibiotics not needed

Salmonella enteritidis
Ferments glucose, not lactose
Produces H2S

LPS.. same as sal. typ

Typhoid fever
Reservoir in gall bladder to reinfect intestine

culture on TSI agar = black

High ID50

Escherichia coli
Gram - rods
faculative anaerobes
Ferments glucose
Ferments lactose

..multiple subtypes listed later

Enterotoxigenic E. coli
Heat-labile toxin = LT1 (cholera.... increases cAMP), LT2 (animal disease)

Heat-stable toxin = STa (increases cGMP which causes H20 hypersecretion), STb (animal disease)

Colonization factors = CF

Do not invade cells, High ID50, colonize small intestine

Virulence factors encoded on plasmid

Enteroinvasive E. coli
Ipas same as Shigella
No actin tail
Plasmid encoded

Like Shigella, but without Shiga toxin --> higher ID50

Colonize *large* intestine.. watery, sometimes dysentary diarrhea

Enteropathogenic E. coli
Bundle forming pilus (BFP)
Type IV pili --> adherence... (then Type III secretion of Tir into host which inserts into host membrane for intimin to bind)
LEE locus encodeds intimin, Tir, and Esp

Don't invade cell! colonize *small* intestines

Fever, nausea, vomiting, diarrhea (especially in infants!)

Enterohemorrhagic E. coli
LEE locus
Shiga-like toxins encoded on bacteriophage

Acid resistant! - low ID50, identify by sorbitol- (which causes it to turn white, instead of red)

Hemorrhagic colitis - caused by shiga toxin.. may progress into hemolytic uremic syndrome

Colonizes *large* intestine

Uropathogenic E. coli
Type I pili and Pap adhesions (tissue tropism)
Hemolysin (HylA) lyses RBCs (by creating pores)
CNF-1 (causes changes in cytoskeleton)

Causes UTIs and pyelonephritis

Septic E. coli
Capsule: K-Ag
Type I pili and S fimbrae (binds cells of choroid plexus/brain ventricles) adhesions
Ibe, and OmpA invasins

Causes sepsis and meningitis

*fatal in new borns*

Sheep Blood agar
alpha: partial clearing, green or brownish ring

beta: wide zone of clearing

gamma: non-hemolytic

Chocolate agar
Selective for organisms like Neisseria or Haemophilus that might not grow on standard media such as TSA..
Thayer-martin agar
Selective for Neisseriaceae
MacConkey agar
Selective for non-fastidious gram-negatives

red colonies ferment lactose (E. coli)

white colonies do not (Salmonella)

EHEC does not ferment sorbitol, other E. coli do

Eosin-methylene blue agar (EMB)
Lactose fermenters = blue/black with metallic sheen

Non-fermenters = colorless or light purple

Hektoen agar
Lactose fermenters = yellow or salmon

Non-Fermenters = colorless

H2S production makes colonies black

Mannitol Salt agar
S. aureus is yellow (ferments mannitol)

other Staph are white

Colistin-naladixic acid (CNA)
Selects against enterics and other gram-negatives
Triple Sugar Iron agar (TSI)
Ferments glucose only = yellow butt, red slant (K/A)

Ferments glucose + lactose/sucrose = yellow butt, yellow slant (A/A)

Non-utilization of all 3 sugars = red butt, red slant (K/K)

H2S (+) = black

Gas production (G) = bubbles

E. coli --> A/AG
Salmonella --> K/A+G
Shigella --> K/A
P. aeruginosa --> K/K

Neisseria (both)
Legionella (not bad)

Neisseria meningiditis
Septic E. coli (SEC)
Salmonella typhi (Vi antigen)
Staph aureus
Strep pyogenes (hyaluronic acid)
Strep pneumoniae

IgA Protease
Strep pneumoniae
Neisseria gonorrhoeae
Neisseria meningiditis

Type III secretion
Shigella dysenteriae
Salmonella typhi
Chlamydia trachomatis

Intracellular pathogens
Shigella dysenteriae
Mycobacterium tuberculosis
Chlamydia trachomatis
Legionella pneumophila
Salmonella spp

vibrio - type IV pillus
Legionella - DOT & ICM (type IV secr)
Borrelia - Osp A, C, E
Neisseria - PI (porin), PII (Opa), PIII (Rmp), Fe binding proteins
Shigella/EIEC - Ipa proteins, IcsA/B
Salmonella - Inv H
EPEC/EHEC - LEE locus, BFP, intimin, Tir, Esp, Type IV pilus

UPEC - type I pilus, Pap
SEC - type I pilus, S-fimbriae, Ibe/OmpA = invasins

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