Biology

Antibiotics and Immunity

974 Questions

Prepare for your science sections with these questions on antibiotics and immunity. The hub covers various classes of antibiotics, their sources, and mechanisms of microbial resistance. It also addresses the human antiviral response.

Antibiotic classes and sourcesMicrobial resistance mechanismsAntiviral proteinsDisease treatments

Antibiotics and Immunity Questions

Multiple choice

Which of the following is the most recently marketed antibiotic and what is its spectrum of activity?

  1. Telavancin/Resistant to Gram-negative organisms and Pseudomonas

  2. Ceftolozane and tazobactam combination/MRSA (methicillin resistant Staphylococcus aureus) and VRE (vancomycin resistant enterococci)

  3. Ceftolozane and tazobactam combination/Resistant to Gram-negative organisms and Pseudomonas

  4. Telavancin/MRSA (methicillin resistant Staphylococcus aureus) and Gram-positive organisms
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ceftolozane/tazobactam combination was marketed in 2015. The combination has activity against many Gram-positive and is resistant to Gram-negative pathogens and Pseudomonas aeruginosa. Thus, ceftolozane and tazobactam combination antibiotic is the latest antibiotic in the market.

Multiple choice

Match the antibiotics with their mechanism of action.

 
Antibiotic MOA
1. Polymyxin B a. Cross linking of DNA
2. Enoxacin b. Disrupts cell membrane function
3. Furazolidone c. Alters bacterial outer membrane permeability
4. Daptomycin d. Inhibits bacterial gyrase
  1. 1. Polymyxin B b. Disrupts cell membrane function
    2. Enoxacin a. Cross linking of DNA
    3. Furazolidone c. Alters bacterial outer membrane permeability
    4. Daptomycin d. Inhibits bacterial gyrase
  2. 1. Polymyxin B c. Alters bacterial outer membrane permeability
    2. Enoxacin d. Inhibits bacterial gyrase
    3. Furazolidone a. Cross linking of DNA
    4. Daptomycin b. Disrupts cell membrane function
  3. 1. Polymyxin B d. Inhibits bacterial gyrase
    2. Enoxacin b. Disrupts cell membrane function
    3. Furazolidone c. Alters bacterial outer membrane permeability
    4. Daptomycin a. Cross linking of DNA
  4. 1. Polymyxin B d. Inhibits bacterial gyrase
    2. Enoxacin a. Cross linking of DNA
    3. Furazolidone b. Disrupts cell membrane function
    4. Daptomycin c. Alters bacterial outer membrane permeability
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This is the correct match. Polymyxin B alters bacterial outer membrane permeability by binding to a negatively charged site in the lipopolysaccharide layer and destabilises the outer membrane. Enoxacin functions by inhibiting bacterial DNA gyrase and topoisomerase IV and prevents bacterial DNA replication, transcription, repair and recombination. Furazolidone works by crosslinking of DNA. Daptomycin disrupts multiple aspects of bacterial cell membrane function which results in bacterial cell death.

Multiple choice

Which of the following features is associated with the lipopolysaccharide layer outside the peptidoglycan cell wall of a gram negative bacterium?

  1. It absorbs and holds gram stain.

  2. It protects the bacterium against certain antibiotics.

  3. It does not contain phospholipids.

  4. It allows the bacterium to attach to solid objects.

  5. It assists in the process of cell division.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A bacterium with an outer membrane is gram negative and protected against certain antibiotics such as penicillin.

Multiple choice

Staphylococcus is a Gram-positive bacteria, which includes several species that can cause a wide variety of infections in humans and other animals through infection or the production of toxins. Staphylococcal toxins are a common cause of food poisoning. What is the shape of the causative agent?

  1. Rod-shaped

  2. Spherical

  3. Spiral

  4. Comma shaped

  5. Square
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Coccus are spherical bacterium, staphylococcus are small colonies of such bacteria.

Multiple choice

It is most difficult to prepare drugs against __________.

  1. bacteria

  2. virus

  3. fungi

  4. protozoa
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Viruses replicate inside host cells using the host's own machinery, making it extremely difficult to develop drugs that target the virus without harming human cells. Bacteria, fungi, and protozoa have their own cellular structures and metabolic pathways that can be selectively targeted with fewer side effects.

Multiple choice

What is the name of an antibiotic that works against bacteria?

  1. Quinine

  2. Penicillin

  3. Chloroquine

  4. Anti-Tetanus Serum
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Penicillin is a classic antibiotic that works against bacteria by disrupting their cell wall synthesis, leading to bacterial death. Quinine and Chloroquine are antimalarial drugs (effective against protozoa, not bacteria), while Anti-Tetanus Serum is an antitoxin providing passive immunity rather than an antibiotic.

Multiple choice

Bacteria make _________ over their body to protect themselves.

  1. cell membrane

  2. cell wall

  3. spores

  4. plasma membrane

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Bacteria have a cell wall made of peptidoglycan that provides structural support and protection. Cell membrane and plasma membrane are the same structure but lack the rigidity of a cell wall. Spores are dormant forms, not protective coatings.

Multiple choice

What is the result of calcium treatment of bacteria?

  1. Bacteria becomes resistant to ampicillin.

  2. Bacteria becomes more permeable to rDNA.

  3. Bacteria gets stained.

  4. Bacterial DNA gets precipitated.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Bacterial cells become competent by treating them with calcium.