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18 Cards in this Set
- Front
- Back
List the identifying characteristics of Bacillus antracis
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Spore forming gram positive (box car shaped bacilli) that are nonhemolytic, PCN susceptible, not motile and have a capsule
This is opposite all of the other bacillus spp |
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Name the three forms on infection by Bacillus antracis
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Cutaneous - papule, ulcer, black necrotic eschar
GI - ulcers in mouth/esophagus, cause bloody diarrhea Inhalation (wool sorters dz) - Initially Fever, SOB, cough followed by edema and *enlargement of mediastinal lymph nodes* followed by meningeal Sx and finally shock and death |
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Describe the identifying characteristics of Listeria monocytogenes
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Gram positive rods (similar to group B strep) that are beta-hemolytic, catalase + and exhibit tumbling motility at room temp
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Name the virulence factors of L. monocytogenes
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invade epithelial cells, M cells and macs via the internalin protein which allows it to move from cell to cell using host cell actin via the ActA gene.
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How are people most commonly infected with Listeria monocytogenes?
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soft cheeses, veggies, cold cuts, read to eat and raw foods
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Who does Listeria monocytogenes infect and describe the Dz caused
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Neonates: Early (causes abscesses and still birth). Late (causes meningitis with septicemia).
Elderly: influenza like illness Pregnant or immunocompromised people: primary bacteremia or disseminated Dz with hypotension and meningitis |
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Describe the identifying characteristics of Erysipelothrix rhuslopathiae
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Erysipelothrix rhuslupathiae forms gram-positive long hair-like filaments that are alpha hemolytic. They produce H2S on triple sugar iron agar (TSI)
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Who gets infected with Erysipelothrix rhuslopathiae?
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Butchers, farmers, fish handlers and veterinarians
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How does infection with Erysipelothrix rhuslopathiae present?
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Erysielpoid - localized skin infections that slowly spreads peripherally. There is no suppuration (unlike strep)
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List the identifying characteristics of Corynebacterium diptheriae
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Clumps of gram positive rods resembling chinese letters. It forms small white nonhemolytic colonies
"It's corny to describe Corynebacterium diptheriae as chinese letters." |
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How does Corynebacterium diptheriae become toxic?
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With infection by the bacteriophage that encodes for Exotoxin (A shuts off protein synthesis and B binds cell receptors)
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How does infection with Corynebacterium diptheriae present?
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Pharyngitis with patchy exudates on tonsil, uvula, soft palate.... tough gray pseudomembrane "leathery skin"
It can lead to respiratory obstruction and suffocation |
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List the identifying characteristics of Arcanobacterium hemolyticum
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gram positive rod, club shaped, beta-hemolytic
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Describe the clinical presentation of arcanobacterium hemolyticum
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symptomatic pharyngitis, fever, cutaneous rash
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Describe the clinical presentation of Nocardia spp
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bronchopulmonary dz, secondary CNS infection (brain abscesses) infections are treated with sulfonamides
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List the identifying characteristics of Nocardia spp
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gram positive, partially/modified acid fast, beaded appearance with flat, white, dry looking colonies... you know what this looks like
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Explain why patients with defects in cellular immunity are particularly susceptible to infections with Listeria monocytogenes
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Listeria monocytogenes is an INTRACELLULAR ORGANISM -- it moves from cell to cell by hijacking Actin gene and
avoids exposure to humoral immune system, thus CELLULAR IMMUNE MECHS are critical for clearance. |
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Name two aerobic Gram-positive rods that can cause food poisoning.
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Bacillus cereus and Listeria monocytogenes
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