Gram negative rods Flashcards
Identify relevant epidemiology and risk factors associated with Proteus vulgaris. (1)
catheterization of urinary tract.
Name the diarrheal organism that ferments lactose and causes bloody diarrhea.
EHEC E.coli 0157:H7
What are the ‘most commons’ associated with Escherichia coli? (4)
most common cause of urinary tract infection. Most common cause of neonatal meningitis. Most common bacterial cause of diarrhea in children in the developing world. Most common cause of traveler’s diarrhea.
Identify relevant epidemiology and risk factors associated with Yersinia pestis. (2)
endemic in rodents in southwestern US, Europe and Southeast Asia. other animals (wolves, coyotes) can also be diseased.
T/F: Citrobacter ferments lactose.
true
What lab findings are useful to help diagnose Pseudomonas aeruginosa? (7)
does not ferment sugars (strict aerobe); oxidase positive; pyocyanin turn infected pus blue; Pyoverdin fluoresces under UV light; colonies have a metallic sheen; distinct fruity odor of corn/potatoes; Produce hydrogen sulphide.
How does Salmonella typhi gram stain?
negative
T/F: Pseudomonas aerugenosa ferments lactose and is oxidase-negative
false-P. Aurugenosa does not ferment lactose and is oxidase negative.
What is the morphology of Escherichia coli?
rod
How does Yersinia pestis gram stain?
negative
T/F: Legionella is transmitted person to person.
false- no person to person transmission
What lab findings are useful to help diagnose Legionella pneumophila? (5)
thin flagellated non-sporulating gram negative rods; requires silver stain (gram stains weakly); requires rich medium with Iron; Infected tissue must be cultured (not sputum); rising serum IgM titres; Urine antigen test.
What lab findings are useful to help diagnose Proteus mirabilis? (5)
highly motile gram negative rods; fast growth; urease positive; does not ferment lactose; swarming on agar.
Name a pathognomic symptom associated with Klebsiella pneumoniae.
jelly-like sputum
Identify relevant epidemiology and risk factors associated with Enterobacter aerogenes. (2)
occurs in mixed nocosomial infections following catheterization and incubation. occasionally associated with community acquired urinary tract infection.
What lab findings are useful to help diagnose Enterobacter aerogenes? (4)
ferment glucose; oxidase negative; reduce nitrates; fast growing shiny colonies on blood agar
How is Yersinia pestis transmitted? (2)
sylvatic cycle (modern)-rodent-flea-human. Urban cycle (historical ‘black death’). Rodent-flea- human and human-human via respiratory droplets.
What is the major reservoir for Yersinia enterocollitica?
contaminated food and water
What are the clinical manifestations of Klebsiella pneumoniae? (1)
classic lobar pneumonia with thick jelly-like sputum that may have blood in it.
What is the major reservoir for Shigella dysenteriae?
mostly human
How is Legionella pneumophila transmitted?
contaminated central water systems. Not spread person to person.
What are the clinical manifestations of enteropathic E. coli?
watery diarrhea
What is the morphology of Enterobacter aerogenes?
rod
Identify relevant epidemiology and risk factors associated with Citrobacter freundii. (2
immunosupression; poor sexual hygeine
Does Salmonella ferment lactose?
no
Identify the major virulence factor associated with Yersinia pestis.
coagulase causes flea to regurgitate Yersinia into organism that it is feeding on
What is the morphology of Shigella dysenteriae?
rod
What is the morphology of Klebsiella pneumoniae?
rod
Does Salmonella enteritidis require a high or a low infection dose?
requires high infectious dose
What are the clnical manifestations of Salmonella enteritidis? (3)
food poisoning (poultry, meat and eggs); diarrhea; septiciemia is rare.
What is the morphology of Proteus mirabilis?
rod
How is Yersinia enterocolitica transmitted?
through pet feces
Where is Yersinia most common?
scandanavia
What is the morphology of Legionella pneumophila?
rod
What is the major reservoir for Yersinia pestis?
rodents and other animals
How does Shigella sonnei gram stain?
negative
What lab findings are useful to help diagnose Yersinia enterocolitica? (1)
oval gram negative rod that is larger than Y. Pestis.
HOw does Proteus mirabilis gram stain?
negative
What kind of injury makes a person especially susceptible to P. aeruginosa infection?
burns
What lab findings are useful to help diagnose Eschericia coli? (6)
will ferment lactose(compare Shigella and Salmonella); indole positive; motile; methyl red positive; citrate negative; gram negative rods, with no particular cell arrangement
What is the morphology of Citrobacter freundili?
rod