Streptomycin

MECHANISM OF ACTION The aminoglycoside antibiotics are rapidly bactericidal. Bacterial killing is concentration-dependent, but residual bactericidal activity persists even after the serum concentration has fallen below the minimum inhibitory concentration. These properties account for the efficacy of once-daily dosing regimens.

Driven by the membrane electrical potential (interior negative), aminoglycosides diffuse through aqueous channels formed by porin proteins in the outer membrane of gram-negative bacteria and enter the periplasmic space. This rate-limiting process (and thus the antimicrobial efficacy of aminoglycosides) can be blocked or inhibited by a reduction in pH or anaerobic conditions, as in an abscess. Once inside the cell, aminoglycosides bind to polysomes and interfere with protein synthesis by causing misreading and premature termination of mRNA translation (Figure 45-2). The resulting aberrant proteins may be inserted into the cell membrane, altering permeability and further stimulating aminoglycoside transport.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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