Group I Group II P. Sulfonamide 1. Peptidoglycan synthesis Q. Quinolones 2. Peptide chain elongation R. Erythromycin 3. Folic acid biosynthesis S. Cephalosporin 4. Topoisomerase
Antibiotic Target Matching
This question requires matching antibiotics from Group I with their respective molecular targets in Group II.
Matching Process
We need to determine the specific mechanism of action for each antibiotic listed:
- P. Sulfonamide: These are structural analogs of para-aminobenzoic acid (PABA). They inhibit the enzyme dihydropteroate synthase, which is crucial for folic acid biosynthesis (Target 3).
- Q. Quinolones: This class of antibiotics, including ciprofloxacin, targets bacterial DNA gyrase and topoisomerase IV, enzymes essential for DNA replication, transcription, repair, and recombination. They inhibit topoisomerase activity (Target 4).
- R. Erythromycin: As a macrolide antibiotic, erythromycin binds to the 50S ribosomal subunit, inhibiting the translocation step of peptide chain elongation during protein synthesis (Target 2).
- S. Cephalosporin: These are beta-lactam antibiotics that inhibit the synthesis of the bacterial cell wall by interfering with peptidoglycan cross-linking. They target peptidoglycan synthesis (Target 1).
Final Matching
Based on the mechanisms described above, the correct pairings are:
- P matches with 3 (Sulfonamide - Folic acid biosynthesis)
- Q matches with 4 (Quinolones - Topoisomerase)
- R matches with 2 (Erythromycin - Peptide chain elongation)
- S matches with 1 (Cephalosporin - Peptidoglycan synthesis)
Therefore, the correct combination is P-3, Q-4, R-2, S-1.
Important Questions from Antibiotics and Antimicrobial Resistance
- Which one of the following antibiotics blocks protein chain elongation by preventing the action of peptidyl transferase ?
Match the antibiotics in Group I with their modes of action in Group II.
Group I Group II P) Chloramphenicol 1) Inhibits protein synthesis by acting on 30S ribosomal subunit Q) Rifampicin 2) Interferes with DNA replication by inhibiting DNA gyrase R) Tetracycline 3) Inhibits protein synthesis by acting on 50S ribosomal subunit S) Quinolone 4) Interferes with RNA polymerase activity 5) Inhibits $\beta$-lactamase activity - Which of the following statement(s) is(are) TRUE about fluoroquinolone drugs?
- A list of pathogens (Group I) and a list of anti-microbial agents (Group II) used to treat their infections are given below. Match the pathogens with the corresponding anti-microbial agents.
Group I Group II [P] Influenza A virus 1. Isoniazid [Q] Fungus 2. Amantadine [R] Plasmodium 3. Fluconazole [S] Mycobacterium 4. Artemisinin 5. Iodoquinol A bacterial culture (200 µl containing $1.8 \times 10^9$ cells) was treated with an antibiotic Z (50 µg per ml) for 4 h at 37°C. After this treatment, the culture was divided into two equal aliquots.
Set A: 100 µl was plated on Luria agar.
Set B: 100 µl was centrifuged, the cell pellet washed and plated on Luria agar.
After incubating these two plates for 24 h at 37°C, Set A plate showed no colonies, whereas the Set B plate showed $0.9 \times 10^9$ cells. This experiment showed that the antibiotic Z is
