Chloramphenicol is an antibiotic produced by a bacterium of the genus Streptomyces, which is then chemically modified to be more effective and resistant to normal bacterial defenses – this makes it a semi-synthetic antibiotic. It is a broad-spectrum drug effective against a large number of pathogens.
Its mode of action is interference with protein synthesis by binding to the 50S subunit of the bacterial ribosome and thus prevention of the formation of the initiation complex (completed assembly of the mRNA, first tRNA, GTP for energy, and the two ribosomal subunits – 50S and 30S).