Chloramphenicol is a synthetic antibiotic, which was first isolated from strains of Streptomyces venezuelae. It has a broad spectrum of activity against Gram-positive and Gram-negative bacteria. Chloramphenicol inhibits bacterial protein synthesis by blocking the peptidyl transferase step (elongation inhibition). It binds to the 50S ribosomal subunit and prevents attachment of aminoacyl tRNA to the ribosome. It inhibits mitochondrial and chloroplast protein synthesis and ribosomal formation of (p)ppGpp, thus de-repressing rRNA transcription.
Chloramphenicol and several analogues inhibited DNA synthesis in Ehrlich Ascites cells under aerobic and anaerobic conditions in the presence and absence of glucose. It is used mainly for opthalmic (eye drops) and veterinary purposes. Used as a seletion agent for transformed cells containing chloramphenicol resistance genes.
Mode of Action: Chloramphenicol inhibits bacterial protein synthesis by blocking the peptidyl transferase step by binding to the 50S ribosomal subunit and preventing attachment of aminoacyl tRNA to the ribosome. It also inhibits mitochondrial and chloroplast protein synthesis and ribosomal formation of (p)ppGpp, de-pressing rRNA transcription.
Mode of Resistance: Use of chloramphenicol acetyltransferase will acetylate the product and inactivate it.
Antimicrobial Spectrum: This is a broad spectrum antibiotic against gram-positive and gram-negative bacteria, and is used mainly for ophthalmic and veterinary purposes.