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
What are the clinical manifestations of Citrobacter freundili?
urinary tract infections
Identify the relevant epidemiology associated with Klebsiella pneumoniae.
immunocompromised patients
How does Shigella dysenterieae gram stain?
negative
HOw does Pseudomonas aeruginosa ram stain?
negative
Identify relevant epidemiology and risk factors associated with Pseudomonas aeruginosa. (2)
can grow in any aqueous environment even thsoe with disinfectants (Hot tubs). Opportunistic.
Identify the major toxicity factors associated with Yersinia enterocolitica.
produces an enterotoxin similar to E. coli ST toxin.
Identify the major toxicity factor associated with Yersinia enterocolitica.
produces an enterotoxin similar to E. coli ST toxin.
How does Citrobacter freundii gram stain?
negative
What is the clinical manifestation of enterotoxic Escherichia coli?
watery diarrhea that resolves in 2-3 days
What are the clinical manifestations of enteroinvasive E. Coli?
bloody, watery diarrhea with mucus and WBCs
How is Escherichia coli transmitted?
contaminated food and water
What are the clinical symptoms of Salmonella typhi (typhoid fever)? (4)
typhoid fever-fever, headache, faint rose coloured rash on the abdomen, diarrhea (translent).
Which gram negative rod ferments lactose and causes non-bloody diarrhea?
enterotoxigenic E. coli
Name five infections commonly caused by Pseudomonas.
pneumonia (esp. in cystic fibrosis), sepsis, external otitis, UTI, hot tub folliculitis
How is Salmonella typhi transmitted?
human to human (fecal to oral)
What is the morphology of Yersinia enterocolitica?
rod
T/F: Pseudomonas aerugenosa is anaerobic gram-negative rod found in water sources
false
What is the morphology of Salmonella typhi?
rod
What is the morphology of pseudomonas aeruginosa?
rod
What lab findings are useful to help diagnose Proteus vulgaris? (4)
highly motile gram negative rods; fast growth; urease positive; does not ferment lactose.
What is the morphology of Salmonella enteritidis?
rod
What is the major reservoir for Salmonella enteritidis?
animal products especially eggs, unpasteurized dairy and chicken
What is pathognomic or the ‘most common’ association with Yersinia pestis?
most virulent bacteria known-a single organism can result in infection.
What are the clinical manifestations of Proteus vulgaris? (1)
urinary tract infections
What is the major reservoir for Salmonella typhi?
humans are the only known reservoir.
Identify the major virulence/toxicity factors associated with Shigella dysenteriae. (2)
shiga toxin can lead to convulsions, coma and death; low infective dose required
Identify the major virulence/toxicity factors associated with Salmonella typhi. (4)
can exist chronically in the gallbladder; fimbria; adhesins; biofilm formation
What is the morphology of Shigella sonnei?
rod
How does Escherichia coli gram stain?
negative
What are the clinical manifestations of Enterobacter aerogenes? (1)
urinary tract infections
What lab findings are useful to help diagnose Yersinia pestis? (4)
bipolar gram negative rod cultured from blood or pus from infected lymph node; grows on most media; immunofluorescent staining makes rapid identification possible.
Which lab findings are useful to help diagnose Klebsiella pneumoniae? (2)
ferments lactose; very large capsule
What are the clinical manifestations of Shigella sonnei? (3)
mild watery diarrhea may progress to abdominal cramps and bloody muccoid diarrhea.
What lab findings are useful to help diagnose Shigella dysenteriae?
not able to ferment lactose; fecal WBC positive
What clinical pearl is associated with Yersinia enterocolitica?
can mimic acute appendicitis
How does Legionella pneumophila gram stain?
negative
Which two toxins does P. Aerugenosa produce?
endotoxin (causes fever and shock), exotoxin A (inactivated EF-2)
T/F: E. coli ferments lactose
true
How does Salmonella enteritidis gram stain?
negative
Name a pathognomic association with Pseudomonas aeruginosa.
pneumonia in people with cystic fibrosis.
What are the clinical manifestations of Proteus mirabilis? (1)
urinary tract infections
Identify the major virulence/toxicity factors associated with Escherichia coli. (4)
has LPS endotoxin in its cell walls and has a capsule. Both of which will produce septicemia. Pili that helps it adhere to cell walls and two exotoxins (enterotoxins) produce osmotic diarrhea. Adhesin
What are the clinical symptoms associated with enterohemorrahgic E. coli (0157:H7)? (5)
severe abdominal cramping; watery then bloody diarrhea 3-10 days; edema; hemorrhage; pseudomembrane in colon.
What is the morphology of Proteus vulgaris?
rod
What is the morphology of Yersinia pestis?
rod
How is Shigella transmitted? (4)
food, fingers, feces and flies
What is the major reservoir for Pseudomonas aeruginosa? (2)
in soil and water everywhere
Identify the major virulence/toxicity factors associated with Legionella pneumophila.(4)
thrives inside macrophages. Chlorine resistant (somewhat). Penicilin resistant. Can survive up to 50 degrees Celsius.
T/F: Enterobactoer aerogenes ferments lactose.
true
What are the clinical manifestations of Legionela pneumophila?
legionalres disease-incubation of 2-10 days followed by flu-like symptoms, cough, diarrhea and delerium; 15% mortality. Pacthy infiltrates on CXR, abnormal liver enzymes
How does Proteus vulgaris gram stain?
negative
How does Enterobacter aerogenes gram stain?
negative
T/F: Klebsiella ferments lactose.
true
What are the clinical manifestations of Shigella dysenteriae? (2)
bacillary dysentary-bloody mucoid diarrhea; convulsions, coma and death
What are the clinical manifestations of Pseudomonas aeruginosa? (3)
pneumonia, otitis externa (swimmer’s ear) and folliculitis.
How does Klebsiella pneumoniae gram stain?
negative
Identify relevant epidemiology and risk factors associated wit Salmonella enteritidis. (3)
mostly western industrialized countries; improper food handling; hypochlorhydria and antacid use increases chances that organism will pass through the stomach into the intestine.
How does Yersinia enterocolitica gram stain?
negative
What are the clinical manifestations of Yersinia enterocolitica? (3)
enterocolitis with fever, abdominal pain, and diarrhea. Also linked to polyarthritis, sepsil, terminal ileitis and acute mesenteric lymphadentitis. Can mimic acute appendicitis.
Identify a nocosomial risk factor associated wit Proteus mirabilis.
catheterization of urinary tract
Identify the major virulence/toxicity factors associated with Klebsiella pneumoniae. (1)
very large capsule prevents phagocytosis
What are the clinical manifestations of Yersinia pestis? (3)
bubonic plague-single tender inflamed lymph node, often in groin, 2-7 days after flea bite with high fever and 75% mortality. Pneumonic plague-if infection spreads to blood stream, eventual hemorrhagic pneumonia, DIC or septic shock and often death. If spread via respirator droplet, 2-3 days incubation followed by progressive flu like syndrome with high mortality
