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  #1  
Old 09-04-2014
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Default Microbiology question for the day!

A 26-year-old Mexican immigrant presents to the clinic with a 3-month history of right upper quadrant abdominal pain. The patient denies any history of fever, vomiting, or diarrhea in the last 6 months. An ultrasound of the right upper quadrant reveals a well-circumscribed circular lesion that is 3 cm in diameter. Laboratory findings are as follows:

WBC count: 9000/mm³
Segmented neutrophils: 56%
Band forms: 4%
Eosinophils: 10%
Basophils: 0.6%
Lymphocytes: 26%
Monocytes: 3%

Which of the following is the most likely morphology of the offending agent?

A.Aerobic gram-negative bacteria
B.Nonmotile gram-negative bacteria
C.Protozoan
D.Tapeworm
E.Trophozoite
F. Virus
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Tapeworm ..echinococcus granulosus or hydatud cyst
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Default Q2

A construction worker accidentally drives a nail into his thigh with a nail gun. The nail is removed, but the area remains painful and edematous, and a diagnosis of cellulitis is made. After a few days the skin over the affected area becomes spongy and, on palpation, produces a crackling sound. A blood-tinged exudate is also observed.
To which of the following organisms was this man most likely exposed?

A.Anaerobic filamentous rod that forms yellow "sulfur granules"
B.Dimorphic fungus that at body temperature appears as cigar-shaped, unequal budding yeast
C.Obligate aerobic rod with a protein capsule
D.Obligate anaerobic rod that produces a phospholipase toxin
E.Obligate anaerobic rod whose spores are often found in soil
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Quote:
Originally Posted by nsesereso View Post
A construction worker accidentally drives a nail into his thigh with a nail gun. The nail is removed, but the area remains painful and edematous, and a diagnosis of cellulitis is made. After a few days the skin over the affected area becomes spongy and, on palpation, produces a crackling sound. A blood-tinged exudate is also observed.
To which of the following organisms was this man most likely exposed?

A.Anaerobic filamentous rod that forms yellow "sulfur granules"
B.Dimorphic fungus that at body temperature appears as cigar-shaped, unequal budding yeast
C.Obligate aerobic rod with a protein capsule
D.Obligate anaerobic rod that produces a phospholipase toxin
E.Obligate anaerobic rod whose spores are often found in soil
I'd Choose E
It's Clostridium Perfringens
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d clostridium perfringes ...gas gangrene ..by alpha toxin lecithinase
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Default Q3

Q3. An Hfr donor cell that is resistant to ceftazidime, ampicillin, vancomycin, gentamicin, and tetracycline is cultured with a bacterial strain that is sensitive to all these drugs. When the resultant recombinants are grown in antibiotic-containing medium, 95% of the isolates grow in the presence of ampicillin, 80% in the presence of gentamicin, 75% with tetracycline, 60% with ceftazidime, and 45% with vancomycin. Which of the following best describes the drug-resistance genes of the Hfr donor cell?

A. The drug-resistance genes are in a bacteriophage genome
B. The drug-resistance genes are in a conjugative plasmid
C. The drug-resistance genes are in an episome
D. The gene in the sequence closest to oriT encodes vancomycin resistance
E. The gene in the sequence farthest from the tra operon encodes ampicillin resistance
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No one is trying Q3!
Or it's so difficult?
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Q1 d
Q2 d
Q3
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Answers 1.D
2.D
Try the Q3 then I will give answer!
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Quote:
Originally Posted by nsesereso View Post
Answers 1.D
2.D
Try the Q3 then I will give answer!
E?
10 charster policy
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Ok more answers
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Q 3. Its E
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please explain
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Default q3

for Q 3 .. D ??
the resistance to vancomycin is greatly reduced which indicates it is near te Ori site ?

still waiting for explanation
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Q3 .. drug resistance gene on plasmid can be transferred thru conjugation.atvthis..orit is at leading point and tra is at end point.so any gene near ori t has more probability to get transferred..as we can see incase of ampicillin (95%)...thus it should be e.
Again its an educated guess, any else explaination pls?
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Any more answers pls? else I will just give answer!
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The correct answer is E. Hfr donor bacteria are capable of transferring chromosomal genes to F- recipient cells. The order of the transfer is from oriT toward the tra operon, although the tra operon is never successfully transferred to the recipient in this case. Thus, the likelihood of successful recombination is a function of the placement of genes on the chromosome. Those closest to oriT are most likely to be successfully transferred (in this case, ampicillin resistance), and those farthest away are least likely (in this case, vancomycin resistance).

If u don't understand tell me and I will add more explanation.
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