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Which form of Bacillus anthracis has spores and how long does it take them to develop?
Non-clinical (2-3 days)
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What are the two plasmids in B. anthracis? What do they code for?
pX01, pX02
pX01= Protective Antigen (PA), Edema Factor (EF), Lethal Factor (LF)
pX02= Carries the capA, capB, and capC genes for capsule synthesis (only observed in clinical)
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Anthrax receptor?
TEM8, CMG2
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How Anthrax Works?
- PA binds to anthrax receptor
- Cleavage of PA by host furin proteases (smaller part is released, larger part stays attached)
- PA63 heptamer fors prepore
- LF and/or EF binds to prepore complex (competitive binding)
- Endocytosis into acidic compartment
- PA heptamer forms pore in compartment
- LF and/or EF released into cytosol
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What is LF? What does it do?
Zing metalloprotease; cleaves MAP kinase --> Necrosis, hypoxia
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What is EF? What does it do?
Adenylate cyclase; increases intracellular cAMP --> Edema
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What makes up the B. anthracis capsule?
poly-D-glu
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Stimulates macrophages to release TNF-a, IL-1B, and other cytokines.
Lethal toxin
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Which of the B. anthracis factors is most immunogenic?
PA
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LF and EF inhibit?
Innate immunity
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B. anthracis is usually infects humans who have exposure to animals because it primarily affects _______.
Herbivores
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3 types of anthrax?
Which two types have no person-to-person spread?
- 1. Inoculation through exposed skin (95%)
- 2. Ingestation
- 3. Inhalation
No person-to-person spread in Ingestation or Inhalation anthrax
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Which form of Bacillus anthracis causes ulcers in mouth or esophagus? What is anothr fact about it?
Ingestion (GI); It is 100% fatal.
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Which form of B. anthracis has a prolonged latent period?
Inhalation (spores can remain latent in nasal passages or reach lower airways)
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Form of B. anthracis that shows mediastinal widening on chestXR?
Inhalation; Nearly 100% mortality in 3 days
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B. anthracis:
Gram-P or Gram-N?
Arrangement, shape?
Spores seen in cultures grown in?
Stain spores with?
- Gram-P
- Rods, single or in chains
- Low CO2Malachite green
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3 stains for the polypeptide capsule of B. anthracis.
India ink, McFadyean methylene blue, DFA
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B. anthracis has what kind of capsule?
Name the other non-polysacharride capusle.
- Protein
- Strep. Pyogenes = Hylauronic acid
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What does B. anthracis' colony look like on blood agar?
What type of hemolysis does it have? Motility
- Ground glass
- No hemolysis, no motility
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Treat B. anthracis with?
What is B. anthracis resistant to?
Ciprofloxacin or doxycycline (susceptible to penicillin, doxyclcine, and cipro)
Resistant to sulfonamides and extended-spectrum cephalosporins
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B. cereus is opportunistic for:
- Gastroenteritis
- Ocular infections
- IV Catheter-related sepsis
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B. cereus: Gastroenteritis
Heat-stable, proteolysis-resistant enterotoxin
Emetic
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B. cerus: Gastorenteritis
Heat-labile enterotoxin
Diarrheal
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Bacillus cereus: Ocular Disease (3 toxins)
- Necrotic toxin
- Cereolysin
- Phospholipase C- lechitinase
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B. cereus emetic disease usually comes from?
Contaminated rice
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B. cereus diarrheal disease from?
Contaminated meat, vegetables, or sauces
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B. cereus must be cultured from the ____
food! (not the feces)
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B. cereus:
Hemolysis?
Motility?
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Prevent B. cereus GI disease with?
Rapid food consumption after cooking; proper refrigeration
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Other Bacillus species:
Gastroenteritis, opportunistic?
Autoclave tester?
Environmental?
Gastroenteritis, opportunistic, pest control?
- B. mycoides
- B. sterothermophilus
- B. subtilis
- B. thuringiensis
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Listeria
Gram-P or Gram-N?
Aerobe/Anaerobe?
Can grow in 1-45 C and in high salt
Motile at RT
Hemolysis?
- Gram-P
- Facultative anaerobe'
- B-hemolysis
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Which bacteria has end-over-end motility?
Listeria
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Facultative intracellular pathogen
Listeria monocytogenes (macrophages, epithelial cells, cultured fibroblasts)
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Leu-rich proteins that interact w/ glycoprotein receptors on host.
Internalins
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L. monocytogenes attaches and enters ____ in _____
Enterocytes in Peyer's Patches
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What do the Listeriolysin O and 2 PLC's of L. monocytogenes do?
Lyse phagosome and release bacteria.
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What bacteria has ActA?
What does it do?
- L. monocytogenes
- Acta is localized at one pole; coordinates actin assembly
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Which type of immunity is important in a L. monocytogenes infection?
CMI (humoral is NOT important)
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Disease of early onset L. monocytogenes
Ganulomatosis infantiseptica (transplacental)
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What bacteria causes bacteremia in pregnant women?
L. monocytogenes
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Bacteria whose hemolysis is enhanced by growing next to S. aureus.
L. monocytogenes
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Treat L. monocytogenes with? It has a natural resistance to what?
- Pen or amp (w/ or w/o genatmicin)
- Has a natural resistance to cephalosporins
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Word association: Ubiquitous
Listeria
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Erysipelothrix rhusiopathiae:
Gram-P or Gram-N?
Shape?
Aerobic/anaerobic?
Ubiquitous in animals; swine
Major disease
- Gram-P
- Pleomorphic
- Facultative anaerobe
- Erysipeloid: Localized skin infection (w/ raised edge)
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E. rhusiopathiae is best prevented by?
Gloves for people at risk (fish handlers, butchers, meat processors, farmers, veterinarians)
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Having complex nutritional requirements for growth.
Fastidious
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H. influenzae and B. pertussis:
Fastidious Gram-N Bacilli
-
-
V factor
Nicotinamide adenine dinucleotide (NAD)
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Haemophilus influenzae requires what two factors for growth?
X & V
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First bacteria to have its genome completely sequenced?
H. influenzae
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4 Virulence factors of H. influenzae:
- Antiphagocytic capsule
- Endotoxin (LOS)
- Ciliostatic factor: arrests cilia motility in vitro
- IgA Protease
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What is NTHi?
Non-typable H. influenzae (lacks the polysaccharide capsule so Abs agains them don't work)
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Polysaccharide Conjugate Vaccine stimulates __________ immunity
T-dependent
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Common cause of COPD exacerbation?
H. influenzae
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Which bacteria colonizes the mucosal membranes of the respiratory tract?
H. influenzae
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Haemophilus aegyptius causes (2 diseases)
- Conjunctivitis
- Brazilian Purpuric Fever
-
Causes chancroids that reemble syphilitic chancer (except these are painful w/ associated lymph node swelling)
Haemophilus ducreyi
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Bacteria colonizes ciliated cells of the respiratory mucosa.
Bordetella pertussis
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3 Stages of Disease in Bordetella Pertussis:
- Cattarrhal 1-2 weeks
- Paroxysmal coughing 2-4 weeks
- Covalescent
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What is used in the B. pertussis vaccine?
Killed phase I cells
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DTP/DTap (What do these letters stand for?)
- D: Diphtheria toxoid
- T: Tetanus toxoid
- P: Whole killed phase I bacterial cells
- ap: Pertussis toxoid, adhesin proteins
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How should adults be vaccinated against B. pertussis?
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How do you treat B. pertussis?
Erythromycin
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