Sheep anti-Chloramphenicol polyclonal antibody for ELISA, IF. Chloramphenicol is an antibiotic that was derived from the bacterium Streptomyces venezuelae. It was the first antibiotic to be manufactured synthetically on a large scale. Chloramphenicol is effective against a wide variety of microorganisms, but due to serious side effects (eg damage to the bone marrow) in humans, it is usually reserved for the treatment of serious and life threatening infections (eg typhoid fever). It is also used in eye drops or ointment to treat bacterial conjunctivitis.