title: A factor involved in chloramphenicol resistance in Streptomyces coelicolor A3(2): its transfer in the absence of the fertility factor.
abstract: An element controlling chloramphenicol resistance (chl) was detected in Streptomyces coelicolor A3(2). Strains sensitive to 1 microgram chloramphenicol ml-1 were obtained among dark scarlet variants. Transfer of the resistance factor was attempted in matings between chloramphenicol-resistant (Chl+) and chloramphenicol-sensitive (Chl-) strains, both of which lacked the SCP1 fertility factor. Transfer of chl was obtained at a much higher rate than that expected for chromosomal markers in SCP1- X SCP1- matings. However, in these particular crosses the latter was also several times higher than usual. All recombinants for chromosomal markers were Chl+. Attempts to locate the chl element failed to distinguish between a chromosomal and an extrachromosomal site. The observed increase in the recombination frequency for chromosomal markers suggests that the chl element may promote recombination.
mesh_terms: D002701:Chloramphenicol / Q000494:pharmacology*; D003227:Conjugation, Genetic; D003433:Crosses, Genetic; D004352:Drug Resistance, Microbial; D005144:F Factor; D011815:R Factors; D013302:Streptomyces / Q000187:drug effects*
chemical_list: D002701:Chloramphenicol