Abstract
Epidemiological and biochemical studies of chloramphenicol (CM) resistance were conducted by using the CM-resistant strains of Staphylococcus aureus which were isolated from clinical specimens. It was found that most of the CM-resistans strains carried quadruple or triple resistance with special reference to tetracycline, streptomycin, penicillin and sulfanilamide, indicating that the CM-resistant staphylococci were multiple-resistant.
The CM-resistant strains of S.aureus isolated from clinical specimens were found to inactivate the drug but not an in vitro developed CM-resistant strain. The inactivated product was found to be 3-acetoxy-CM. Induction of CM resistance in Saureus was then studied by using several CM derivatives. It was found that the derivatives were classified into three groups; (1) high antibacterial activity and induction of CM resiatance, (2) low antibacterial activity and induction of CM resistance, and (3) loss of both activities. These results strongly suggeste that the mechanism ot CM resistance is different from that of the induction of CM resistance.
