Aminoglycosides are a class of antibiotics including gentamicin, tobramycin, amikacin, neomycin, plazomicin, and streptomycin. The class binds the 30S ribosomal subunit to inhibit bacterial protein synthesis Synthesis Polymerase Chain Reaction (PCR). Unlike other medications with a similar mechanism of action, aminoglycosides are bactericidal Bactericidal Penicillins. Aminoglycosides provide coverage against aerobic gram-negative pathogens, including Pseudomonas Pseudomonas Pseudomonas is a non-lactose-fermenting, gram-negative bacillus that produces pyocyanin, which gives it a characteristic blue-green color. Pseudomonas is found ubiquitously in the environment, as well as in moist reservoirs, such as hospital sinks and respiratory equipment. Pseudomonas. Aminoglycosides can also be used synergistically with inhibitors of bacterial cell wall Cell wall The outermost layer of a cell in most plants; bacteria; fungi; and algae. The cell wall is usually a rigid structure that lies external to the cell membrane, and provides a protective barrier against physical or chemical agents. Cell Types: Eukaryotic versus Prokaryotic synthesis Synthesis Polymerase Chain Reaction (PCR) (e.g., β lactams) for gram-positive Gram-Positive Penicillins pathogens. Use is limited by serious side effects, including nephrotoxicity Nephrotoxicity Glycopeptides and ototoxicity Ototoxicity Damage to the ear or its function secondary to exposure to toxic substances such as drugs used in chemotherapy; immunotherapy; or radiation. Glycopeptides.
Last updated: 8 Jul, 2021
Chemical structure of gentamicin:
a core hexose ring (2-deoxystreptamine in the center) with 2 amino sugar molecules attached
The site of action for aminoglycosides, which target the 30S ribosomal subunit
tRNA
tRNA
The small RNA molecules, 73-80 nucleotides long, that function during translation (translation, genetic) to align amino acids at the ribosomes in a sequence determined by the mRNA (RNA, messenger). There are about 30 different transfer rnas. Each recognizes a specific codon set on the mRNA through its own anticodon and as aminoacyl trnas (RNA, transfer, amino Acyl), each carries a specific amino acid to the ribosome to add to the elongating peptide chains.
RNA Types and Structure: transfer
RNA
RNA
A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity.
RNA Types and Structure
mRNA
mRNA
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3′ end, referred to as the poly(a) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
RNA Types and Structure: messenger
RNA
RNA
A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity.
RNA Types and Structure
Several mechanisms of aminoglycoside resistance Resistance Physiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow. Ventilation: Mechanics of Breathing:
The following table compares antibiotics, which inhibit bacterial protein synthesis Synthesis Polymerase Chain Reaction (PCR):
Drug class | Mechanism of action | Coverage | Adverse effects |
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Amphenicols |
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Lincosamides Lincosamides The lincosamides, lincomycin and clindamycin, are inhibitors of bacterial protein synthesis. Drugs in this class share the same binding site as that of macrolides and amphenicols; however, they differ in chemical structure. Lincosamides target the 50S ribosomal subunit and interfere with transpeptidation. Lincosamides |
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Macrolides Macrolides Macrolides and ketolides are antibiotics that inhibit bacterial protein synthesis by binding to the 50S ribosomal subunit and blocking transpeptidation. These antibiotics have a broad spectrum of antimicrobial activity but are best known for their coverage of atypical microorganisms. Macrolides and Ketolides |
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Oxazolidinones Oxazolidinones The oxazolidinones (linezolid and tedizolid) are bacterial protein synthesis inhibitors. Their unique binding site on the 23S ribosomal RNA of the 50S ribosome gives them zero cross-resistance with other antibiotics. Oxazolidinones |
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Gram-positive
Gram-Positive
Penicillins
cocci
Cocci
Bacteriology:
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Antibiotic
sensitivity
Sensitivity
Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives.
Blotting Techniques:
Chart comparing the microbial coverage of different antibiotics for
gram-positive
Gram-Positive
Penicillins
cocci
Cocci
Bacteriology, gram-negative
bacilli
Bacilli
Shigella, and
anaerobes
Anaerobes
Lincosamides.