25/12/2017 · Effect of Rifamycin on Protein Synthesis

Rifampicin produces a dose-dependent decrease in protein synthesis in rat thymocytes

Effect of rifampicin on poxvirus protein synthesis.

N2 - Streptococcus agalactiae (group B Streptococcus, GBS) is an important cause of sepsis and meningitis in neonates, and excessive production of the inflammatory mediators tumor necrosis factor (TNF) and nitric oxide (NO) causes tissue injury during severe infections. We hypothesized that exposure of GBS to different antimicrobial agents would affect the magnitude of the macrophage inflammatory response to this organism. We stimulated RAW 264.7 murine macrophages with a type-Ia GBS isolate in the presence of ampicillin, cefotaxime, rifampin, clindamycin, or gentamicin, singly or in combination. We found that GBS exposed to rifampin or clindamycin (versus beta-lactam antibiotics) stimulated less TNF secretion and inducible nitric oxide synthase (iNOS) protein accumulation in RAW 264.7 cells. Furthermore, GBS exposed to combinations of antibiotics that included a protein synthesis inhibitor stimulated less macrophage TNF and iNOS production than did organisms exposed to beta-lactam antibiotics singly or in combination. We conclude that exposure of GBS to rifampin or clindamycin leads to a less pronounced macrophage inflammatory mediator response than does exposure of the organism to cell wall-active antibiotics.

Tetracyclines are protein synthesis inhibitors primary targeting the 30S ribosome. They are essentially bacteriostatic.

Inhibition of Plasmodium falciparum Protein Synthesis

AB - Streptococcus agalactiae (group B Streptococcus, GBS) is an important cause of sepsis and meningitis in neonates, and excessive production of the inflammatory mediators tumor necrosis factor (TNF) and nitric oxide (NO) causes tissue injury during severe infections. We hypothesized that exposure of GBS to different antimicrobial agents would affect the magnitude of the macrophage inflammatory response to this organism. We stimulated RAW 264.7 murine macrophages with a type-Ia GBS isolate in the presence of ampicillin, cefotaxime, rifampin, clindamycin, or gentamicin, singly or in combination. We found that GBS exposed to rifampin or clindamycin (versus beta-lactam antibiotics) stimulated less TNF secretion and inducible nitric oxide synthase (iNOS) protein accumulation in RAW 264.7 cells. Furthermore, GBS exposed to combinations of antibiotics that included a protein synthesis inhibitor stimulated less macrophage TNF and iNOS production than did organisms exposed to beta-lactam antibiotics singly or in combination. We conclude that exposure of GBS to rifampin or clindamycin leads to a less pronounced macrophage inflammatory mediator response than does exposure of the organism to cell wall-active antibiotics.

Both NS and L proteins are required for in vitro RNA synthesis by vesicular stomatitis virus

The aminoglycosides are products of species and are represented by streptomycin, kanamycin,tobramycin and gentamicin. These antibiotics exert theiractivity by binding to bacterial ribosomes and preventing theinitiation of protein synthesis.

Inhibition of Plasmodium falciparum Protein Synthesis TARGETING THE ..


Antibiotics: Protein Synthesis, Nucleic Acid Synthesis …

The tetracyclines consist of eight related antibiotics whichare all natural products of , although some can nowbe produced semisynthetically or synthetically. Tetracycline, chlortetracyclineand doxycycline are the best known. The tetracyclines arebroad-spectrum antibiotics with a wide range of activity against bothGram-positive and Gram-negative bacteria. is less sensitive but is generally susceptible to tetracyclineconcentrations that are obtainable in the bladder. The tetracyclinesact by blocking the binding of aminoacyl tRNA to the A site on theribosome. Tetracyclines inhibit protein synthesis on isolated 70S or80S (eucaryotic) ribosomes, and in both cases, their effect is on thesmall ribosomal subunit. However, most bacteria possess an activetransport system for tetracycline that will allow intracellularaccumulation of the antibiotic at concentrations 50 times as great asthat in the medium. This greatly enhances its antibacterialeffectiveness and accounts for its specificity of action, since aneffective concentration cannot be accumulated in animal cells. Thus ablood level of tetracycline which is harmless toanimal tissues can halt protein synthesis in invading bacteria.

the change in the protein synthesis ..

A rifampin-susceptible strain (VSV Rif+) was selected from the wild vesicular stomatitis virus (VSV) population unsusceptible to rifampin. The VSV Rif+ was blocked in its intracellular replication in the presence of rifampin. In cells, rifampin affected primarily VSV Rif+ transcription, but to a different extent than in a cell-free system. In addition, a decrease in the amount of VSV Rif+ protein M was detected, linked to a stimulation of protein NS. In the absence of rifampin, protein M, although synthesized, was not immediately incorporated into the cell membrane. An interpretation of these observations is proposed.