ICAR AIEEA (PG): Master's entrance, Veterinary Science and Animal Sciences · India · NTA for ICAR
Original practice questions written to the published syllabus · not past papersAntibacterial, antifungal, antiprotozoal, anthelmintic, ectoparasiticide and anticancer drugs, and the prudent use that slows antimicrobial resistance.
In the exams: ICAR AIEEA-PG 13 Unit IV (drug resistance); ICAR AICE-JRF core group 07; EAEVE Day One prescribing competences
ICAR AIEEA-PG (Code 13, unit IV: pharmacology, toxicology and AMR)
Mechanism of action of each antibacterial class and its target (PBP, 30S, 50S, gyrase, folate pathway), bactericidal versus bacteriostatic, sulphonamide-trimethoprim synergy, mechanisms of drug resistance, anthelmintic classes and their targets, anticoccidials and babesiacides, signature toxicities.
How our questions for ICAR AIEEA spread across the units of Veterinary Chemotherapy & Antimicrobial Stewardship. Difficulty: 15 easy, 14 medium, 0 hard.
| Antiprotozoal drugs | 4 | |
| Mechanisms and problems of drug resistance | 4 | |
| Anthelmintics | 3 | |
| Critically important antimicrobials | 3 | |
| Sulphonamides | 2 | |
| Beta-lactam antibiotics | 2 | |
| Aminoglycosides | 2 | |
| Tetracyclines | 2 | |
| Ectoparasiticides | 2 | |
| Macrolides | 1 | |
| Fluoroquinolones | 1 | |
| Antifungal drugs | 1 | |
| Anticancer drugs | 1 | |
| Prudent use of antimicrobials | 1 |
Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.
High-level resistance to almost all aminoglycosides, including amikacin, in a Gram-negative isolate most strongly suggests
A. a 16S rRNA methyltransferase gene such as armA or rmtB
16S rRNA methyltransferases modify the binding site and confer high-level resistance across the class. Individual modifying enzymes usually spare some members; amikacin resists many of them.
Further reading: Giguère, Prescott & Dowling, Antimicrobial Therapy in Veterinary Medicine, 5th ed.
Tetracyclines inhibit bacterial protein synthesis by
A. blocking aminoacyl-tRNA binding at the 30S acceptor site
Tetracyclines stop aminoacyl-tRNA reaching the A site of the 30S subunit and are bacteriostatic. mRNA misreading is the aminoglycoside mechanism; the exit tunnel is the macrolide site; peptidyl transferase is the amphenicol and pleuromutilin site.
Further reading: Riviere & Papich, Veterinary Pharmacology and Therapeutics, 10th ed.
In Gram-negative bacteria the primary target of fluoroquinolones is
C. DNA gyrase, a type II topoisomerase
Fluoroquinolones inhibit DNA gyrase, mainly in Gram-negatives, and topoisomerase IV, mainly in Gram-positives.
Further reading: Riviere & Papich, Veterinary Pharmacology and Therapeutics, 10th ed.
Azole antifungals act by inhibiting
D. lanosterol 14-alpha-demethylase in ergosterol synthesis
Azoles block the cytochrome P450 enzyme lanosterol 14-alpha-demethylase. Squalene epoxidase is the terbinafine target, glucan synthase the echinocandin target and microtubules the griseofulvin target.
Further reading: Riviere & Papich, Veterinary Pharmacology and Therapeutics, 10th ed.
In broiler production, a 'shuttle' anticoccidial programme means
A. using different anticoccidials in the starter and grower feeds of one flock
A shuttle changes drug within one flock's life; rotation changes drug between flocks. Both aim to slow resistance.
Further reading: Taylor, Coop & Wall, Veterinary Parasitology, 4th ed.
Isoxazoline parasiticides such as fluralaner and afoxolaner kill fleas and ticks by
D. blocking GABA- and glutamate-gated chloride channels
Isoxazolines are antagonists of insect and acarine GABA- and glutamate-gated chloride channels. Chitin inhibition describes lufenuron and juvenile hormone mimicry describes methoprene and pyriproxyfen.
Further reading: Riviere & Papich, Veterinary Pharmacology and Therapeutics, 10th ed.
Vincristine and vinblastine arrest tumour cells in mitosis by
C. binding tubulin and preventing spindle formation
Vinca alkaloids are M-phase-specific tubulin binders. DNA cross-linking describes alkylating and platinum drugs, dihydrofolate reductase inhibition methotrexate, and intercalation the anthracyclines.
Further reading: Withrow & MacEwen's Small Animal Clinical Oncology
Transfer of a resistance plasmid from one bacterium to another through direct cell-to-cell contact is called
B. conjugation
Conjugation transfers plasmids through direct contact. Transduction uses bacteriophages; transformation is uptake of free DNA; transposition is movement of a transposon within or between DNA molecules in one cell.
Further reading: Giguère, Prescott & Dowling, Antimicrobial Therapy in Veterinary Medicine, 5th ed.
Which group was listed by WHO (6th revision) among the highest priority critically important antimicrobials?
B. Third- and higher-generation cephalosporins
The HPCIA in the 6th revision were 3rd-5th generation cephalosporins, glycopeptides, macrolides and ketolides, polymyxins and quinolones. The 2024 Medically Important Antimicrobials List revised the categories, so check the current edition.
Further reading: WHO Critically Important Antimicrobials, 6th revision (2018); WHO Medically Important Antimicrobials List (2024)
The ban on the glycopeptide growth promoter avoparcin in the EU in 1997 was prompted mainly by
C. the link between avoparcin use and vancomycin-resistant enterococci
Avoparcin selected for vanA-type vancomycin-resistant enterococci in animals and the food chain, cross-resisting with the human last-line drug vancomycin. mcr-1 was reported in 2015.
Further reading: Giguère, Prescott & Dowling, Antimicrobial Therapy in Veterinary Medicine, 5th ed.
Ten here, 29 in the app. The Laisha app has every practice question we have written to ICAR AIEEA in this subject, marked as you go, with timed papers, a jump-to-unanswered list and a certificate when you pass at 70 per cent.
Free for ten days, then one subscription of US$10 a month. We would rather say so here than have you find it later.
An AI operating system for agriculture: free guides, manuals and tools written for every country.