MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 56 Mcqs, each offering curated multiple-choice questions to sharpen your Microbiology knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The antibiotics not having good activity against is |
| A. | clindamycin |
| B. | cefoxitin |
| C. | trimethoprim-sulphamethoxazole |
| D. | ciprofloxacin |
| Answer» B. cefoxitin | |
| 2. |
The antibiotics not clinically useful for infection is |
| A. | aminoglycosides |
| B. | ceftazidime |
| C. | piperacillin |
| D. | trimethoprim-sulphamethoxazole |
| Answer» E. | |
| 3. |
The antibiotics which affords a broad spectrum of antimicrobial coverage against aerobic and anaerobic bacteria, , , and is |
| A. | gentamicin |
| B. | tetracycline |
| C. | metronidazole |
| D. | vancomycin |
| Answer» C. metronidazole | |
| 4. |
Which of the following antibiotics can't be used for treatment of infections with β-lactamase-producing ? |
| A. | Vancomycin |
| B. | Ampicillin/sulbactam |
| C. | Cephalothin |
| D. | Piperacillin |
| Answer» E. | |
| 5. |
Chelate forming peptide antibiotic are/is |
| A. | bleomycins |
| B. | sideromycins |
| C. | both (a) and (b) |
| D. | vancomycin |
| Answer» D. vancomycin | |
| 6. |
The third generation cephalosporin agents is |
| A. | cefotaxime |
| B. | cefoxitin |
| C. | cephalothin |
| D. | cephalexin |
| Answer» B. cefoxitin | |
| 7. |
The antibiotics not having good activity against Enterobacteriaceae is |
| A. | clindamycin |
| B. | cefoxitin |
| C. | trimethoprim-sulphamethoxazole |
| D. | ciprofloxacin |
| Answer» B. cefoxitin | |
| 8. |
Quinones and related antibiotics are |
| A. | tetracyclines |
| B. | actinorhodin |
| C. | mitomycin |
| D. | all of these |
| Answer» E. | |
| 9. |
Both penicillin and fluoroquinolones |
| A. | bind to and inactivate a bacterial protein |
| B. | inhibit the cross-linking of peptidoglycan |
| C. | are inactivated by -lactamase |
| D. | must be transported into the cytoplasm in order to act |
| Answer» B. inhibit the cross-linking of peptidoglycan | |
| 10. |
The scientist who first discovered the substance penicillin was |
| A. | Joseph Lister |
| B. | Alexander Fleming |
| C. | Paul Ehrlich |
| D. | none of these |
| Answer» C. Paul Ehrlich | |
| 11. |
The larger the __________ , the better the chemotherapeutic agent. |
| A. | therapeutic index |
| B. | therapeutic dose |
| C. | selective toxicity |
| D. | spectrum |
| Answer» B. therapeutic dose | |
| 12. |
Which of the following may cause resistance to penicillin? |
| A. | Impermeability of cell envelope |
| B. | Production of -lactamases by bacteria |
| C. | Alteration or lack of penicillin-binding proteins |
| D. | All of the above |
| Answer» E. | |
| 13. |
The penicillin resistant to -lactamases is |
| A. | carbenicillin |
| B. | closacillin |
| C. | penicillin-G |
| D. | ampicillin |
| Answer» C. penicillin-G | |
| 14. |
The antibiotics not clinically useful for Pseudomonas aeruginosa infection is |
| A. | aminoglycosides |
| B. | ceftazidime |
| C. | piperacillin |
| D. | trimethoprim-sulphamethoxazole |
| Answer» E. | |
| 15. |
Which of the following drugs may show plasmid-mediated resistance? |
| A. | Nalidixic acid |
| B. | Ampicillin |
| C. | Rifampicin |
| D. | Methicillin |
| Answer» C. Rifampicin | |
| 16. |
Quinolones are |
| A. | antimetabolites |
| B. | penicillin derivatives |
| C. | bacteriostatic |
| D. | broad-spectrum |
| Answer» E. | |
| 17. |
Which of the following is not a semi synthetic chemotherapeutic agent? |
| A. | Ampicillin |
| B. | Carbenicillin |
| C. | Penicillin |
| D. | Sulfonamide |
| Answer» D. Sulfonamide | |
| 18. |
Which of the following tests is used to determine the minimal lethal concentration? |
| A. | Broth dilution test |
| B. | Agar dilution test |
| C. | Dilution susceptibility tests |
| D. | All of these |
| Answer» E. | |
| 19. |
The mode of action of polymyxin is to |
| A. | inhibit protein synthesis |
| B. | inhibit DNA synthesis |
| C. | injury to the plasma membrane |
| D. | inhibit folic acid synthesis |
| Answer» D. inhibit folic acid synthesis | |
| 20. |
Polyene antibiotics are |
| A. | large ring structures |
| B. | -lactam - thiazolidine ring |
| C. | small ring structures |
| D. | any of these |
| Answer» B. -lactam - thiazolidine ring | |
| 21. |
A parenteral route of drug administration refers to |
| A. | oral |
| B. | nonoral |
| C. | intravenously |
| D. | intramuscularly |
| Answer» C. intravenously | |
| 22. |
Which of the following antibiotics can't be used for treatment of infections with -lactamase-producing Staphylococcus aureus? |
| A. | Vancomycin |
| B. | Ampicillin/sulbactam |
| C. | Cephalothin |
| D. | Piperacillin |
| Answer» E. | |
| 23. |
The nitrofurans differ from the antibiotics in that they |
| A. | do not occur naturally |
| B. | occur naturally |
| C. | are antimicrobial drugs |
| D. | all of these |
| Answer» B. occur naturally | |
| 24. |
The susceptibility of a microorganism to antibiotics and other chemotherapeutic agents can be determined by using |
| A. | tube dilution technique |
| B. | paper disk plate |
| C. | both (a) and (b) |
| D. | none of these |
| Answer» D. none of these | |
| 25. |
Most antibiotics are isolated from |
| A. | viruses |
| B. | aquatic microorganisms |
| C. | soil microorganisms |
| D. | plants |
| Answer» D. plants | |
| 26. |
Which of the following drugs involves modification of the drug by enzymatic modification or degradation of its active element to alter its/their resistance? |
| A. | Pencillins |
| B. | Choloramphenicol |
| C. | Aminoglyosides |
| D. | All of these |
| Answer» E. | |
| 27. |
Who developed the concept of specific toxicity? |
| A. | Pasteur |
| B. | Fleming |
| C. | Watson |
| D. | Ehrlich |
| Answer» E. | |
| 28. |
More promising chemotherapeutic agents for treating viral diseases is |
| A. | leukocytic interferon |
| B. | fibroblast interferon |
| C. | interferon |
| D. | nystatin |
| Answer» D. nystatin | |
| 29. |
Which of the following methods would be most appropriate for sterilizing an antibiotic solution? |
| A. | Dry heat sterilization |
| B. | Microfiltration |
| C. | Autoclaving |
| D. | Desiccation |
| Answer» C. Autoclaving | |
| 30. |
Fluoroquinolones are antibiotics which inhibit |
| A. | DNA polymerase |
| B. | RNA polymerase |
| C. | DNA gyrase |
| D. | Cross-linking of peptidoglycan |
| Answer» D. Cross-linking of peptidoglycan | |
| 31. |
Which of the following is used only in life-threatening situations when no other drug is adequate? |
| A. | Penicillin |
| B. | Tetracycline |
| C. | Chloramphenicol |
| D. | Streptomycin |
| Answer» D. Streptomycin | |
| 32. |
Chemotherapeutic agents must |
| A. | prevent/destroy the activity of a parasite |
| B. | leave unaltered the host's natural defense mechanisms |
| C. | be able to come in contact with the parasite by penetrating the cells |
| D. | all of the above |
| Answer» E. | |
| 33. |
Interference mechanism of ciprofloxacin and norfloxacin is due to their action on |
| A. | cell wall synthesis |
| B. | cell membrane function |
| C. | DNA function |
| D. | protein synthesis |
| Answer» D. protein synthesis | |
| 34. |
When using alcohol as an antiseptic, which concentration is considered most effective? |
| A. | 95% |
| B. | 50% |
| C. | 70% |
| D. | 25% |
| Answer» D. 25% | |
| 35. |
By which of the following means antifungal chemotherapeutic agents may affect fungi? |
| A. | Interfere with nuclear division by preventing the aggregation of microtubules needed for mitosis |
| B. | Interfere with normal nucleic acid synthesis |
| C. | Interfere with ergosterol biosynthesis and thus alter the structure of the cytoplasmic membrane as well as the function of several membrane-bound enzymes like those involved in nutrient transport and chitin synthesis |
| D. | all of these |
| Answer» E. | |
| 36. |
With which of the following aminoglycosides interfere? |
| A. | Protein synthesis |
| B. | DNA function |
| C. | Cell wall synthesis |
| D. | Cell membrane function |
| Answer» B. DNA function | |
| 37. |
Which of the following protein synthesis mechanisms may be affected by particular drugs? |
| A. | Peptide bond formation |
| B. | mRNA translocation |
| C. | Aminoacyl-tRNA binding |
| D. | All of these |
| Answer» E. | |
| 38. |
Which of the following is not an example of potent antitumer agents? |
| A. | Anthramycin |
| B. | Sibromycin |
| C. | Neothramycin |
| D. | Erythromycin |
| Answer» E. | |
| 39. |
Which of the following group is not the carbohydrate containing antibiotic? |
| A. | Streptomycin & Streptothricin |
| B. | Vancomycin & Moenomycin |
| C. | Everninomycin & Nogirimycin |
| D. | Erythromycin & candicidin |
| Answer» E. | |
| 40. |
The penicillin stable in gastric acid and suitable for oral administration is |
| A. | methicillin |
| B. | carbenicillin |
| C. | closacillin |
| D. | pencillin-G |
| Answer» D. pencillin-G | |
| 41. |
A broad-spectrum antibiotic such as chloramphenicol is one that |
| A. | kills both Gram positive and Gram negative bacteria |
| B. | kills all bacteria |
| C. | kills numerous types of microbes |
| D. | kills all microorganisms |
| Answer» D. kills all microorganisms | |
| 42. |
Amphotericin B and polymyxin interfere with |
| A. | cell wall synthesis |
| B. | protein synthesis |
| C. | cell membrane function |
| D. | DNA function |
| Answer» D. DNA function | |
| 43. |
Which of the following is not -lactamase-resistant penicillin? |
| A. | Oxacillin |
| B. | Nafcillin |
| C. | Carbenicillin |
| D. | Methicillin |
| Answer» D. Methicillin | |
| 44. |
The antibiotics which affords a broad spectrum of antimicrobial coverage against aerobic and anaerobic bacteria, rickettsiae, chlamydiae, and mycoplasmas is |
| A. | gentamicin |
| B. | tetracycline |
| C. | metronidazole |
| D. | vancomycin |
| Answer» C. metronidazole | |
| 45. |
Nystatin is a drug used for treatment of diseases caused by |
| A. | gram negative bacterium |
| B. | gram positive bacterium |
| C. | yeast |
| D. | protozoan |
| Answer» D. protozoan | |
| 46. |
Which is not an amino acid and peptide antibiotic? |
| A. | Penicillin |
| B. | Actinomycin |
| C. | Bacitracin |
| D. | Tetranactin |
| Answer» E. | |
| 47. |
Cephalosporins and Penicillins interfere with which of the following? |
| A. | Protein synthesis |
| B. | DNA function |
| C. | Cell membrane function |
| D. | Cell wall synthesis |
| Answer» E. | |
| 48. |
The compound(s) which act(s) as metabolic antagonist is/are |
| A. | trimethoprim |
| B. | sulphonamides |
| C. | both (a) and (b) |
| D. | none of these |
| Answer» D. none of these | |
| 49. |
The most selective antibiotics are those that interfere with the synthesis of |
| A. | bacterial DNA |
| B. | bacterial RNA |
| C. | bacterial cell walls |
| D. | bacterial plasma membrane |
| Answer» D. bacterial plasma membrane | |
| 50. |
Cycloserine inhibits |
| A. | alanine racemase |
| B. | D-alanyl - D-alanine synthetase |
| C. | Both (a) and (b) |
| D. | amidase |
| Answer» D. amidase | |