Which of the following is the most likely explanation for multiple drug resistance to antibiotics that spreads from one type of bacteria to another?
Antibiotic drug resistance can occur through bacterial cell mutation, adaptation, or gene transfer. The best route for multiple drug resistance that spreads from one type of bacteria to another is via plasmid or chromosomal gene transfer.
Penicillins inhibit which of the following bacterial processes/ compounds?
Penicillins inhibit synthesis of the bacterial cell wall. Chloramphenicol, tetracyclines, macrolides, ketolides, oxazolidinones, aminoglycosides, spectinomycin, and the lincomycin bind to bacterial ribosomes to inhibit protein synthesis. The fluoroquinolones inhibit activity of bacterial topoisomerase to inhibit protein synthesis, and the sulfonamides inhibit bacterial dihydropteroate synthase to block folic acid synthesis and cell growth.
Ototoxicity and nephrotoxicity are characteristic adverse effects of which of the following?
Ototoxicity and nephrotoxicity are characteristic adverse effects of aminoglycosides. Chloramphenicol can cause GI (gastrointestinal) disturbances, reversible suppression of bone marrow, and rarely aplastic anemia. As a group, the β-lactam antibiotics can cause hypersensitivity and have the potential to cause anaphylactic shock. The fluoroquinolones can cause GI disturbances, reversible arthropathy, and arrhythmias.
Pharmacology pearls
β-Lactam antibiotics inactivate bacterial transpeptidases and prevent the cross-linking of peptidoglycan polymers essential for cell-wall integrity.
Both penicillin and amoxicillin are susceptible to β-lactamases.
To prevent its metabolism, imipenem is administered with an inhibitor of renal tubule dehydropeptidase, cilastatin.
Vancomycin, which is unaffected by β-lactamases, is active against gram-positive bacteria.
Chloramphenicol can cause gastrointestinal disturbances, reversible suppression of bone marrow, and rarely aplastic anemia
Aminoglycosides may cause ototoxicity or nephrotoxicity and should be used with caution in those patients who have renal insufficiency or who are elderly.