What is the mechanism of antibacterial action of aminoglycoside antibiotics?

Aminoglycoside antibiotics are a class of alkaline antibiotics with strong water solubility and more stable nature, which are extracted from the culture fluid of Streptomyces or Aeromonas or semi-synthesized from natural antibiotics as raw materials. At present, the aminoglycoside antibiotics commonly used in veterinary clinics are streptomycin, neomycin, kanamycin, gentamicin, genta-minor nosocomial, amikacin, nertilmicin, macromycin, ampicillin, and so on.

The main mechanism of action is to interfere with the information ribonucleic acid and ribonucleoprotein body 30S subunit binding and inhibit the peptide chain extension, inhibit the synthesis of bacterial proteins, high concentration of bactericidal effect, low concentration of bacteriostatic effect. It can also increase the permeability of bacterial cell membrane, so that potassium ions, enzymes and other important physiological substances in the cytoplasm of extravasation, and cause bacterial death. This class of drugs on the stationary phase of the bacterial killing effect is strong, for a class of stationary phase bactericidal drugs.

The antibacterial spectrum of aminoglycosides is mainly Gram-negative bacilli, such as Escherichia coli, Pneumococcus, dysentery bacilli, Brucella, Bartonella, etc., and it is ineffective against anaerobic bacteria. Weak against Gram-positive bacteria, but more sensitive to Staphylococcus aureus (including drug-resistant strains). Stronger effect in alkaline environment. Significant post-antibiotic effect (PAE) against Gram-negative bacilli and positive cocci. Aminoglycosides are poorly absorbed orally and can only be used for intestinal infections. They are well administered by injection and most are excreted in their native form via the kidneys.

Aminoglycoside antibiotics have strong toxic side effects, and special attention should be paid to the application. The main manifestations: first, nephrotoxicity. Damage to the proximal tubular epithelial cells, proteinuria, hematuria, renal hypoplasia, the incidence of gentamicin is higher. Because it is mainly excreted from the urinary tract, in order to minimize the accumulation of drug damage, the affected animals should be given a sufficient amount of water. Second, ototoxicity. It can be manifested as vestibular dysfunction and cochlear nerve damage. Use with caution in animals that require acute hearing. Aminoglycosides can pass through the placenta into the fetus, thus injection of these drugs into pregnant animals can cause nephrotoxicity or hearing impairment in newborn animals. Third, neuromuscular blockade. Symptoms of myocardial depression and respiratory failure, neomycin, streptomycin and kanamycin occur more often, can be countered by intravenous injection of neostigmine and calcium. Fourth, internal use may damage the intestinal wall villi and affect the absorption of the intestinal tract, can also cause intestinal flora disorders, etc. Rabbits are prone to gastrointestinal flora disorders, should be avoided.