Chloramphenicol is a broad-spectrum antibiotic that was first isolated from Streptomyces venezuelae in 1947. The drug was subsequently chemically synthesized. It has both a bacteriostatic and bactericidal effect; in the usual therapeutic concentrations it is bacteriostatic. Chloramphenicol is used for the treatment of serious gram-negative, gram-positive, and anaerobic infections. It is especially useful in the treatment of meningitis, typhoid fever, and cystic fibrosis. It should be reserved for infections for which other drugs are ineffective or contraindicated. Chloramphenicol, a small inhibitor of bacterial protein synthesis, is active against a variety of bacteria and readily enters the CSF. It has been used extensively in the last decades for the treatment of bacterial meningitis. In industrialized countries, chloramphenicol is restricted mostly to topical uses because of the risk of induction of aplastic anemia. However, it remains a valuable reserve antibiotic for patients with allergy to β-lactam antibiotics or with CNS infections caused by multiresistant pathogens.

Dextramycin ((S, S)-p-Chloramphenicol) is an optical isomer of Chloramphenicol, a broad-spectrum antibiotic with historical veterinary use in all major food-producing animals. The drug is biosynthesized by the soil organism Streptomyces venezuelae and several other actinomycetes and is chemically synthesized for commercial use. Chloramphenicol occurs in the meta-configuration and in the para-configuration and it contains two chiral centers thus in total eight different isomeric configurations exist. All para-stereoisomers are biologically active and 0.5% solution of Dextramycin shows antimicrobial activity. Currently, Chloramphenicol has banned for use in all food-producing animals.