Clinical Microbiology ID Review Flashcards
Gram stain reveals the morphology of a suspected organism. The results reveal the bacteria is Gram positive cocci in clusters. Which of the following are possible classifications of the bacteria? (Select All)
A. S. pneumoniae
B. S. aureus
C. S. epidermidis
D. E. Fascium
E. S. saprophyticus
B. S. aureus
C. S. epidermidis
E. S. saprophyticus
Gram stain reveals the morphology of a suspected organism. The results reveal the bacteria is Gram positive cocci in clusters and coagulase test results are positive. Which of the following bacteria represent these findings?
A. S. agalactiae
B. S. aureus
C. S. epidermidis
D. S. pneumoniae
E. Listeria spp.
B. S. aureus
Gram stain reveals the morphology of a suspected organism. The results reveal the bacteria is Gram positive cocci in pairs. Which of the following are possible classifications of the bacteria? (Select All)
A. S. pneumoniae
B. S. aureus
C. E. faecium
D. E. faecalis
E. Listeria spp.
A. S. pneumoniae
C. E. faecium
D. E. faecalis
Gram stain reveals the morphology of a suspected organism. The results reveal the bacteria is alpha hemolytic, Gram positive cocci in clusters. Which of the following bacteria represent the description given?
A. Clostridum spp.
B. S. aureus
C. E. faecalis
D. S. epidermidis
E. S. pneumoniae
E. S. pneumoniae
Gram stain reveals the morphology of a suspected organism. The results reveal the bacteria is gamma hemolytic, gram positive cocci in clusters. Which of the following are possible classifications of the bacteria? (Select All)
A. E. faecium
B. S. pneumoniae
C. E. coli
D. Klebsiella
E. E. faecalis
A. E. faecium
E. E. faecalis
A patient reports to the hospital with a respiratory rate of 28, HR of 126 and a blood pressure of 92/48 mmHg. The patient is in a state of sepsis secondary to an untreated diabetic foot infection. Emperic treatment is started and the cultures are taken. Gram-stain results are pending but placing the bacteria in a test tube of hydrogen peroxide yields a bubbling-type reaction. Which of the following can be concluded about the suspected bacteria?
A. The bacteria is a type of coagulase negative streptococci.
B. The infection is most likely staphylococcal in nature.
C. The bacteria is a type of beta-hemolytic streoptococci.
D. The infection is most likely streptococcal in nature.
B. The infection is most likely staphylococcal in nature.
The test using hydrogen peroxide is known as the catalase test. It is used to differentiate catalase producing bacteria (Staphylococcus) from non-catalase producing bacteria (streptococci/enterococci). The production of bubbles in the test means that the enzyme catalase is being produced by the bacteria. Catalase hydrolizes hydrogen peroxide to H2O and O2. The resulting oxygen creates the bubbling effect. Staphylococcus produces catalase while streptococcus and enterococcus do not, hence this particular bacteria is most likely staphylococcal in nature.
Cultures reveal the morphology of a suspected organism. The results reveal the bacteria is Gram negative cocci. Which of the following bacteria may be present?
A. Klebsiella
B. Neisseria spp.
C. M. catarrhalis
D. B and C
E. All are examples of gram negative cocci
D. B and C (Neisseria and M. catarrhalis)
Cultures reveal the morphology of a suspected organism. The results reveal the bacteria is a Gram negative bacilli that shows evidence of lactose fermentation. Which of the following bacteria is NOT a potential bacteria present?
A. Pseudomonas
B. Citrobacter
C. Serratia spp.
D. Enterobacter spp.
E. Klebsiella
A. Pseudomonas
Cultures reveal the morphology of a suspected organism. The results reveal the bacteria is a Gram negative cocco-bacillus. Which of the following statements is true regarding this bacteria? (Select All)
A. The organism could possibly be H. influenzae
B. The organism is most likely a lactose fermenter
C. The organism could possibly be Pseudomonas or Proteus
D. The organism could possibly be Acinetobacter spp.
E. The organism could possibly be Bacteroides or Prevotella
A. The organism could possibly be H. influenzae
D. The organism could possibly be Acinetobacter spp.
Cultures reveal the morphology of a suspected organism. The results reveal the bacteria is a Gram negative aerobic bacillus that ferments lactose. Which of the following statements is true regarding this bacteria?
A. If placed on a MacConkey Agar plate the bacteria will appear pink in color
B. If placed on a MacConkey Agar plate the bacterial colonies will remain clear in appearance
C. If placed on a MacConkey Agar plate the bacteria will cause a green discoloration
D. If placed on a MacConkey Agar plate the bacteria will cause a yellow discoloration.
A. If placed on a MacConkey Agar plate the bacteria will appear pink in color.
When a bacteria is able to ferment lactose it produces acid which lowers the pH of the MacConkey Agar plate in the area the bacteria are colonizing. When this happens the color changes from the neutral red color of the agar to a pink color, thus indicating lactose fermentation.
Cultures reveal the morphology of a suspected organism. The results reveal the bacteria is a Gram negative and does not ferment lactose. Which of the following is NOT a possible bacteria matching this description?
A. Pseudomonas
B. Proteus spp.
C. Acinetobacter
D. H. influenzae
E. Enterobacter spp.
E. Enterobacter spp.
Which of the following is an example of an Anaerobic Gram-negative bacilli?
A. E. coli
B. Neisseria spp.
C. Bacteroides spp.
D. Proteus spp.
E. Acinetobacter.
C. Bacteroides
A sample of bacteria was isolated from an infected wound and cultured on a MacConkey Agar plate. The bacterial colonies produced a pink discoloration. Which of the following statements is true? (Select all)
A. The bacteria is most likely a non-lactose fermenter
B. The bacteria could possibly be Serratia
C. The bacteria is most likely gram postivie
D. The bacteria could possibly be E. coli
E. The bacteria most likely ferments lactose
B. The bacteria could possibly be Serratia
D. The bacteria could possibly be E. coli
E. The bacteria most likely ferments lactose
MacConkey Agar is selective towards gram negative bacteria and contains bile acids and crystal violet that prevents the growth of gram positive bacteria.
When a bacteria ferments lactose it appears pink in color so it cannot be answer choice A.
