7. Gram+ & Gram- Bacteria II Flashcards
A scientist is testing a bacteria. First he gram stains it and it turns purple. Next he applies the catalase test and it does not bubble. Next he test hemolysis and it completely hemolysis. Finally he test for Bacitracin sensitivity and find that it is sensitive. Which bacteria is been tested?
A. Staphylococcus Aureus B. Listeria C.Streptococcus Pneumoniae D. Streptococcus Bovis E. Streptococcus Pyogenes F. Streptococcus agalactiae
RFA
Ans E. Streptococcus Pyogenes
A. Staphylococcus Aureus
+ catalase test(bubbles)
+ coagulase
+mannitol
B- Listeria- is a Bacilli bacteria, these test are for cocci bacteria
C. Streptococcus Pneumoniae-
-Catalase
Partial Hemolysis
Optochin sensitive
D. Streptococcus Bovis
-catalase
No hemolysis
No growth 6.5% NaCl
F. Streptococcus agalactiae
-catalase
Complete hemolysis
Not Bacitracin sensitive
A student is in a lab given a sample of Staphylococcus Epidermidis and told to test to prove the validity of the sample. If it is valid sample what test process should be produced
A.Catalase(+), Coagulase(-), Novobiocin sensitive(+), Mannitol fermentation(+)
B.Catalase(-), Coagulase(-), Novobiocin sensitive(-), Mannitol fermentation(+)
C.Catalase(+), Coagulase(+), Novobiocin sensitive(+), Mannitol fermentation(+)
D. Catalase(+), Coagulase(-), Novobiocin sensitive(+), Mannitol fermentation(-)
E. Catalase(-), Coagulase(-), Novobiocin sensitive(+), Mannitol fermentation(-)
F. Catalase(+), Coagulase(-), Novobiocin sensitive(-), Mannitol fermentation(+)
RFA
Ans D. Catalase(+), Coagulase(-), Novobiocin sensitive(+), Mannitol fermentation(-)
A. Staphylococcus Epidermidis
does not ferment Mannitol
(this does not fit a bacteria we have)
B. Should eliminate this one from the get go because since it is Staph it will have a + catalase
C. This would be right for Staph. Aureus ( though they don’t test Novobiocin sensitivity for it)
E. Again negative Catalase is for Strep not Staph
F. This is for Staph Saprophyticus not Staph Epidermidis
A collected stool sample was not processed properly causing Shigella and Salmonella to die. Which improper technique would cause this to occur?
A. Refrigerating the swab prior to specimen collection
B. Not plating the sample on Thayer-Martin medium
C. Allowing the sample to decrease temperature, decreasing pH
D. Not incubating the sample in CO2
E. Not using the ‘clean-catch’ method
SZ
Ans C.
Fecal matter should be processed immediately to prevent decreasing temperature and causing pH to decrease. Fecal bacteria are obligate, aerotolerant, and facultative anaerobes.
Choice A, B, D
Refrigeration of swabs kills Neisseria gonorrhea (GC). GC requires Thayer-Martin medium and CO2 incubation.
Choice E “Clean-catch’ method refers to obtaining urine samples
A midstream urine sample is obtained. A calibrated loop of 0.01 mL is used to inoculate the blood agar. The plate incubates at 37 degrees Celsius overnight. 250 colonies are counted the following day. Calculate the number of colony forming units present.
A. 2,500 B. 25,000 C. 37,000 D. 250,000 E. 370,000
SZ
Ans B 25,000
CFU= #colonies x dilution factor
When using 0.01 mL loop you must take into consideration the dilution and multiple by 100.
A man who was just minding his own business hanging out at the beach, all of a sudden develops a huge eye infection. Which of the following bacteria are potentially causes of such an infection?
A. Neisseria Gonorrhoeae B. Pseudomonas Aeruginosa C. Listeria monocytesogenes D. Staphylococcus Epidermidis E. Clostridium F. AIDS
FA
A. Neisseria Gonorrhoeae is one of the possible bacteria, along with Staphylococcus Aureus, and Chlamydia Trachomatis
Pt comes into the clinic because of “burning in mah dick hole”. You order a urine sample but because he is drunk he whips it out right there and starts peeing. A young 3rd year med student who originally hails from Florida jumps into action and ____ because _____
A) Directs the Pt to move his stream into the cup, because Chlamydia and gonorrhea are found this way
B) tells the patient to only collect the last few drops, because Chlamydia and gonorrhea are found deep into the bladder
C) Dives toward the naked man and collects the first bit of urine, because Chlamydia and gonorrhea infect at the tip of the urethra and this is the only way to ID it properly
D) Goes to collect the urine but slips and falls, because he secretly likes it
MM
Answer C
Pt comes into clinic with ear/sinus pain. You figure out it is a bacterial infection because you are a smart young doctor. Which of the following is most likely?
A) Moraxella Catarralis B) Chlamydia Trachomatis C) E. coli D) Klebsiella Pneumonia E) Pasteurella Multocida
MM
Answer A - found in ears, sinus, and Upper respiratory tract
B) Chlamydia Trachomatis - dicks and eyes
C) E. coli - UTI and gastric
D) Klebsiella Pneumonia - lungs….
E) Pasteurella Multocida - skin infection
What is the difference between bacteremia and septicemia? (MG)
A. Bacteremia is symptomatic, septicemia is not
B. Septicemia is symptomatic, bacteremia is not
C. Both are symptomatic, but they are caused by different microorganisms
D. Neither are symptomatic- the terms just describe the presence of two different microooganisms in the blood
B. Septicemia is symptomatic, bacteremia is not
Bacteria in the blood = bacteremia
bacteria in the blood + chills, fever, prostration, other toxins in blood = septicemia
Coughing up sputum samples often results in just saliva. How can you ensure a better sample in a patient with suspected TB? (MG)
A. Bronchial aspiration
B. Transtracheal aspiration
C. Pleural aspiration
D. Pericardial aspiration
A. Bronchial aspiration
B. Transtracheal aspiration
Both of these
Describe the process in which one can obtain a sterile Urine Sample in a patient who is not being tested for Chlamydia or Gonorrhea and why we use this method.
FA
Using a clean-catch midstream urine, you avoid contaminating the sample with indigenous microflora of the distal Urethra during voiding.
