MCQ on Bacterial Pathogenesis: Medical Microbiology

    Key aspects of Bacterial pathogenesis
    • Adherence and Colonization
    • Invasion
    • Immune Evasion
    • Toxin Production
    • Nutrient Acquisition
    • Host Cell Manipulation
    • Inflammation and Tissue Damage 

                     Multiple Choice Question on Bacterial Pathogenesis

1) Which of the following microorganism is the major inhabitant of the human skin?
a) Escherichia coli
b) Staphylococcus epidermidis
c) Staphylococcus aureus
d) Streptococcus pyogenes

2) Select all the medically important bacteria which are frequently isolated as a major pathogen of human infections?
a) Enteric bacteria 
b) Pseudomonas spp
c) Plasmodium spp
d) Staphylococcus spp
e) Mucor spp
f) Mycobacterium spp

3) All of the following pathogens are the major congenital pathogens that are transmitted from infected mother to baby, Except?
a) Treponema pallidum
b) Zika virus
c) Herpesvirus
d) Clostridium perfringens

4) Which of the following cocci-shaped bacteria usually grow in pairs?
a) Klebsiella spp
b) Neisseria spp
c) Pseudomonas spp
d) Clostridium spp
e) Nocardia spp

5) Which of the following microbe can live only inside the cell (obligate intracellular pathogen)?
a) Salmonella
b) Mycobacterium
c) Rickettsia
d) Vibrio

6) ..................................... is the normal flora of the upper respiratory tract of the human body, overgrowth of the bacteria may lead to respiratory tract infection.
a) Lactobacillus acidophilus
b) Streptococcus spp
c) Vibrio cholerae
d) Clostridium difficile

7) Which of the following bacteria releases an endotoxin that causes muscular paralysis and ultimately may lead to infection of nervous system?
a) Clostridium botulinum
b) Bacillus cereus
c) Streptococcus pyogenes
d) Salmonella typhi

8) Staphylococcus spp produces which of the following enzyme?
a) Proteases
b) Lipase
c) Hyaluronidase
d) Coagulase

9) Which of the following bacteria is predominantly present as a normal flora in the urogenital tract of a mother and a newborn female infant?
a) Candida albicans
b) Lactobacillus acidophilus
c) Histoplasma capsulatum
d) Neisseria gonorroheae

10) Which of the following gram positive bacteria is the causative pathogen for infection known as 'lock jaw'?
a) Clostridium tetani
b) Neisseria gonorroheae 
c) Yersinia pestis
d) Mycobacterium leprae

11) Name the bacterial pathogen transmitted to humans by the bite of fleas and can cause a serious and deadly infection
a) Salmonella typhi
b) Yersinia pestis
c) Shigella dysenteriae
d) Escherichia coli

12) Some bacteria and fungi need an iron receptors molecule for their growth which is an important virulence factor of bacterial pathogenesis, what is it called?
a) Siderophores
b) Ionophores
c) Siderocytes
d) None of the above

13) Which toxin is produced by Streptococcus pyogenes?
a) Shiga like toxin
b) Alpha toxin
c) Erythrogenic toxin
d) Cyanotoxin

14) Name the bacteria that is a common cause of toxic shock syndrome
a) Staphylococcus epidermidis
b) Staphylococcus aureus
c) Staphylococcus intermedius
d) None of the above

15) Catalase test is the common biochemical test used for the identification of various bacteria. 
Which of the following bacteria does not have this enzyme?
a) Enterobacter
b) Pseudomonas
c) Corynebacterium
d) Streptococci

16) Staphylococcus aureus releases various types of toxins that increase the virulence of the bacteria, Select all the toxins released by S. aureus:
a) Aflatoxin
b) Mycotoxin
c) Leucocidin
d) Enterotoxin

17) Which pathogen is a major cause of dental disease?
a) Staphylococcus epidermidis
b) Streptococcus mutans
c) Staphylococcus aureus
d) Streptococcus agalactiae

18) The microorganism that commonly causes an eye infection is.............................
a) Chlamydia trachomatis
b) Staphylococcus aureus
c) Streptococcus pneumoniae
d) Streptococcus sanguinis

19) The most significant bacteria found in acne is .............................acnes.
a) Staphylococcus
b) Streptococcus
c) Propionibacterium
d) Bacillus

20) Which of the following bacteria is predominantly present as normal flora in urine?
a) Escherichia coli
b) Staphylococcus epidermidis
c) Staphylococcus aureus
d) Streptococcus pyogenes

21) The virulence factors of a bacteria are the important constituents of the bacteria that help in invading the host and initiating the infection. 
Select all the important virulence factors which help in the process of bacterial pathogenesis:
b)Exotoxins and endotoxins
c)Pili/ fimbriae
e) All of the above

22) Name the most possible bacteria associated with the opportunistic infections that occur in patients who have cystic fibrosis
a) Staphylococcus aureus
b) Pseudomonas aeruginosa
c) Chlamydia trachomatis
d) Candida albicans

23) Select all the microorganisms which are commonly transmitted to humans by the vectors such as ticks and fleas.
a) Rickettsia spp
b) Yersinia spp
c) Borrelia spp
d) Bacillus spp

24)Which of the following toxins releasing bacteria are common worldwide human gastroenteritis pathogens?
a) Salmonella typhi
b) Streptococcus pneumoniae
c) Cryptococcus neoformans
d) Clostridium botulinum

25) Name the possible bacterial pathogen that can invade the skin and cause tissue damage in humans
a) Rhizopus stolonifer
b) Bacillus cereus
c) Clostridium perfringens
d) Proteus mirabilis

Multiple Choice Answer Review:
1- b) Staphylococcus epidermidis

2-a), b), d), and f). c) Plasmodium spp is a parasite, a causative agent of malaria, e) Mucor spp is a fungi.
3- d) C. perfringens, is a bacteria that causes foodborne illness and most commonly found on raw meat and poultry.

4-b) Neisseria spp, usually grows in pair (diplococci). a) Klebsiella spp, c) Pseudomonas spp, d) Clostridium spp and e) Nocardia spp are rod shaped (bacilli) bacteria.

5-c) Rickettsia spp

6- b) Streptococcus spp, is a normal flora of upper respiratory tract, overgrowth of the bacteria results in infection of the respiratory tract. a) Lactobacillus acidophilus is a normal flora of intestine and vagina, c) Vibrio cholerae is a bacterial pathogen that causes foodborne illness and d) Clostridium difficile is a normal flora of the colon, overgrowth of the bacteria leads to inflammation of the colon, it can also be transmitted from person to person by spores.

7-a) Clostridium botulinum, is a bacteria that produces a potent neurotoxin responsible for the development of botulism.

8-d) Coagulase

9-b) Lactobacillus acidophilus, a) Candida albicans is a yeast, c) Histoplasma capsulatum is a dimorphic fungus, d) Neisseria gonorroheae is a diplococcus bacteria causes gonorrhea that is a sexually transmitted disease.

10-a) Clostridium tetani, a neurotoxin producing pathogen of  that causes Tetanus, also known as 'lock jaw' infection. b) Neisseria gonorroheae, c) Yersinia pestis and d) Mycobacterium leprae are gram negative bacteria.

11-b) Yersinia pestis. a) Salmonella typhi, c) Shigella dysenteriae and d) Escherichia coli are bacteria that causes foodborne illnesses.

12-a) Siderophores
13-b) Alpha toxin
14-b) Staphylococcus aureus
15-d) Streptococci
16-c), and d)
17-b) Streptococcus mutans
18-a) Chlamydia trachomatis
19-c) Propionibacterium
20-a) Escherichia coli
21-f) All of the above
22-b)P. aeruginosa

23-a), b), and c). d) Bacillus spp commonly causes foodborne illnesses that is transmitted to humans through consumption of contaminated water and food.

24-a) and d). b) Streptococcus pneumoniae is a bacteria and c) Cryptococcus neoformans fungus that do not produce toxins.

25- c)Clostridium perfringens, a) Rhizopus stolonifer is a fungal pathogen common in bread. b) Bacillus cereus is a bacteria commonly causes foodborne illness, d) Proteus mirabilis is a common bacterial pathogen of urinary tract infection (UTI).