MCQ on Gram Positive Cocci (Streptococcus pyogenes, Streptococcus pneumoniae, Staphylococcus aureus)

Gram-Positive Cocci (Streptococcus spp, Staphylococcus spp) -Multiple Choice Question

1) A 2-day-old premature baby boy born to a 22-year-old woman developed pneumonia. The mother showed the symptoms of urinary tract infection after the delivery. A blood specimen was taken from the baby for the laboratory diagnosis. Beta-hemolytic colonies appeared on the culture plate after 24 hours. 
Which of the following group B streptococci could be the possible pathogen that can be easily spread from the mother to the baby and cause pneumonia?
a) Streptococcus pyogenes 
b) Streptococcus agalactiae 
c) Enterococcus faecalis
d) Streptococcus bovis 

2) Which of the following bacteria is the most commonly isolated pathogen from the infection known as pharyngitis?
a) Streptococcus pneumoniae
b) Staphylococcus aureus
c) Streptococcus pyogenes
d) Mycoplasma pneumoniae

3) A 4-year-old boy developed an erythematous rash around his face and arms with skin color turning red, during the physical examination swollen lymph nodes around the infection were reported but no other symptoms were seen. The specimen was collected from the infected area, and the pathogen was identified as a gram-positive coccus.
What could be the possible diagnosis?
a) Glomerulonephritis
b) Erysipelas
c) Impetigo
d) Cellulitis

4) The possible pathogen for the above disease condition is.............................
a) Pseudomonas aeruginosa
b) Staphylococcus aureus 
c) Streptococcus agalactiae
d) Trichophyton rubrum

5) All of the following are the characteristics of Streptococcus pneumoniae, Except?
a) The colonies are diplococcus and encapsulated
b) Alpha hemolytic colonies appear in blood culture media
c) It is present as normal flora in healthy individuals
d) It grows well in a high concentration of glucose media 

6) Which of the following bacteria is the common pathogen found in otitis media?
a) Streptococcus pneumoniae 
b) Streptococcus agalactiae
c) Streptococcus pyogenes
d) Streptococcus intermedius

7) Which of the following cocci is a part of the normal flora of the mouth?
a) Streptococcus agalactiae
b) Staphylococcus saprophyticus
c) Staphylococcus epidermidis
d) Streptococcus mutans

8) What are the different infections caused by Group A Streptococcus spp
Select all the correct answers:
a) Pharyngitis
b) Impetigo
c) Scarlet fever
d) Meningitis

9) Which of the following bacteria are examples of Group D Streptococci?
a) Streptococcus mutans
b) Streptococcus bovis and Enterococcus faecalis
c) Streptococcus pyogenes and Enterococcus gallinarum
d) Streptococcus pneumoniae

10) Each of the following statements is correct about Enterococcus spp, Except?
a) They can grow in both aerobic and anaerobic conditions
b) Resistant to high salt concentrations
c) The morphological characteristics resemble that of S. pyogenes
d) The common cause of hospital-acquired infections

11) Name the cocci that are a part of the normal flora of human intestines? 
Select the correct answer: 
a) Enterococcus faecalis
b) Micrococcus luteus
c) Staphylococcus epidermidis
d) Streptococcus mutans

12) Which of the following is NOT the virulent factor, an important antigenic property of S. pyogenes?
a) M protein
b) Streptolysin
c) Streptokinase
d) Endotoxins

13) Which of the following pathogen is the main cause of endocarditis in individuals with heart disease?
a) Streptococcus intermedius
b) Enterococcus faecalis
c) Streptococcus suis
d) Micrococcus luteus

14) Which of the following antibiotics have been found to be most effective for the treatment of infections caused by Enterococcus faecalis?
a) Cephalosporin
b) Macrolide
c) Aminoglycoside with penicillin
d) Oral penicillin V with ampicillin

15) Which of the following bacteria have been found to be most resistant to the drug vancomycin?
a) Enterococcus faecium
b) Streptococcus pyogenes
c) Staphylococcus aureus
d) Lactobacillus acidophilus 

16) All of the following are the general characteristics of Micrococcus spp and Staphylococcus spp, Except?
a. On blood agar Micrococcus spp appear as smaller colonies than Staphylococcus spp
b. Micrococcus is ubiquitous in nature
c. Both are catalase-positive
d. Staphylococcus spp are more virulent than Micrococcus spp 
e.  None of the above  

17) Which of the following bacteria is Not is a part of the normal human microbiota?
a. Streptococcus agalactiae
b. Staphylococcus aureus
c. Streptococcus pyogens (A)
d. Enterococcus faecalis
e. Staphylococcus saprophyticus

18) Viridans Streptococci are all, Except?
a. Most of them show alpha hemolysis on sheep blood agar
b. Found as the most common pathogen in dental caries
c. Not groupable according to Lancefield serology
d. All of the pathogens are catalase negative
e. Found only in the oral cavities as commensals    

19) A urine sample was taken from a 30-year-old who had symptoms related to a urinary tract infection, she complained of painful and frequent urination with blood in the urine. 
Which of the following pathogen is less commonly isolated from the urine sample?
a. Streptococcus mutans
b. E.coli
c. Staphylococcus aureus
d. Streptococcus agalactiae

20) All of the following statements regarding coagulase-negative Staphylococcus spp (CONS) are true, Except?
a. S. epidermidis and S. saprophyticus are coagulase-negative
b. Infection with S. epidermidis are mainly hospital-acquired
c. S. saprophyticus is a normal flora of humans skin surface
d. Both are common pathogens in urinary tract infections

21) Majority of strains of Staphylococci are highly resistant to which of the following antibiotics?
a) Cephalosporins
b) Clotrimazole
c) Amphotericin
d) Penicillin

22) Name the constituent found in the cell wall of gram-positive cocci?
a) Lipopolysaccharide
b) Teichoic acid
c) Mycolic acid
d) Endotoxins

23) Which of the following bacteria is also called the gamma or nonhemolytic streptococci?
a) Streptococcus faecalis
b) Streptococcus pyogenes
c) Streptococcus agalactiae
d) None of the above

24) Which of the following statements is Not true about the hemolysins produced by Streptococci?
a) Produce streptolysin O and S
b)An important virulence factor
c)Commonly produced by S. agalactiae
d) Observed around the colonies on blood agar 

25) A pus specimen cultured in blood agar, is incubated at 37-degree Celcius for 24 hours. 
Select all the possible laboratory results from the options below:
a) Gram-positive cocci shaped bacteria may be observed
b) Gram-positive bacteria in chains may be identified
c) Pink rods/bacilli bacteria may be isolated and identified
d) None of the above

Multiple Choice Answers:
1-b) Streptococcus agalactiae also known as Group B streptococci infection is high in pregnant women. a) Streptococcus pyogenes is Group A streptococcus, d) Streptococcus bovis is a Group D streptococcus, c) Enterococcus faecalis formerly classified as Group D streptococci. 

2-c) Streptococcus pyogenes, a Group A streptococcus
3-c) Impetigo 
4-b) Staphylococcus aureus 
5-d) It grows well in a high concentration of glucose media 
6-a) Streptococcus pneumoniae 
7-d) Streptococcus mutans
8- a), b) & c) 
9-b) Streptococcus bovis and Enterococcus faecalis
10-c) The morphological characteristics resemble that of S. pyogenes 
11-a) Enterococcus faecalis 
12-d) Endotoxins 
13-b) Enterococcus faecalis 
14-c) Aminoglycoside with penicillin 
15-a) Enterococcus faecium 
16-e) None of the above
17- c) Streptococcus pyogens (A)
18- e) Found only in the oral cavities as commensals
19- a) S. mutans
20- c) S. saprophyticus is a normal flora of humans skin surface
21- d)Penicillins
22- b) Teichoic acid
23- a)Streptococcus faecalis
24- c)Commonly produced by S. agalactiae
25- a), b) and c)


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