Question

12. Which of the following antimicrobial agents has the fewest side effects? a. Tetracycline b. Penicillin c. Chloramphenicol d. Erythromycin 13. Which of the following antibodies does not interfere with cell wall synthesis? a. Cephalosporins b. Natural penicillins c. Semisynthetic penicillins d. Macrolides e. Vancomycin 14. Which of the following would be selective against tubercle bacillus? a. b. e. d. e. Vancomycin- inhibits peptidoglycan synthesis Bacitracin- inhibits peptidoglycan synthesis Streptomycin- inhibits protein synthesis Ethambutol- inhibits mycolic acid synthesis Streptogramin- inhibits protein synthesis 15. Warts are caused by a. Poxvirus b. Papillomavirus c. Herpes virus d. Staphylococcus aureus e. Parvovirus She most 16. A patient has pus-filled vesicles and scabs on her face, throat, and lower back. likely has: a. Chickenpox b. Measles c. Rubella d. Smallpox e. Mumps 17. The patient has vesicles and scabs over her forehead. Microscopic examination of skin scrapings shows gram-positive cocci in clusters. The etiology is: a. Microsporum

Answer 1

12. Ans- b. penicillin
Among the above antibiotics, penicillins have fewest side effects of which some are common but not serious and does not cause birth defects.
13. Ans- d. macrolides
Explanation:
The major antibiotics that inhibit bacterial cell wall synthesis are penicillin and cephalosporins. Other antibiotics such as vancomycin, fosfomycin, and bacitracin are also used to inhibit cell wall synthesis.
14. Ans- d. ethambutol-inhibits mycolic acid synthesis
Explanation:
Mycolic acids are the major lipid component of the cell wall responsible that protect the tuberculosis bacilli from many outside threats. The antibiotics is selected first after diagnosis of a fresh infection are -
1. For first 2 months: combination of INH + rifampin + pyrazinamide, or INH + rifampin + ethambutol
2. For the subsequent 4 months: the combination of INH + rifampin
3. For the subsequent 6-12 months: Maintenance therapy with INH
15. Ans-b. papillomavirus
Warts are a type of infection that occurs in the top layer of skin and caused by human papillomavirus, or HPV.