| Title: | Genetic and physiological analysis of conjugation in Streptococcus faecalis |
| Author(s): | Dunny G; Yuhasz M; Ehrenfeld E; |
| DOI: | 10.1128/jb.151.2.855-859.1982 |
| ISSN/ISBN: | 0021-9193 (Print) 1098-5530 (Electronic) 0021-9193 (Linking) |
| Abstract: | "In an effort to elucidate the mechanisms of conjugal plasmid transfer in Streptococcus faecalis, a genetic analysis of the sex pheromone-dependent tetracycline resistance plasmid pCF-10 was initiated. Rare transconjugants obtained from short matings with wild-type donors not exposed to sex pheromones were screened for increased donor potential in a subsequent mating. From this screening, a mutant plasmid, designated pCF-11, whose transfer functions are expressed in the absence of pheromone induction was isolated. Cells carrying pCF-11 spontaneously clump when grown in broth culture but do not excrete sex pheromones active against wild-type donors. In the course of initial experiments, it was observed that physiological conditions could affect plasmid transfer frequency. Therefore, a set of standardized optimal mating conditions was defined. The experiments carried out to determine these conditions revealed that a transient increase in transfer frequency of about 2 order of magnitude occurred in early-exponential-phase donor cells. This peak of activity is independent of sex pheromone response, since it was observed with induced or uninduced donor cells carrying either pCF-11 or pCF-10" |
| Keywords: | "*Conjugation, Genetic/drug effects Enterococcus faecalis/*genetics/physiology Mutation R Factors;" |
| Notes: | "MedlineDunny, G Yuhasz, M Ehrenfeld, E eng Research Support, U.S. Gov't, P.H.S. 1982/08/01 J Bacteriol. 1982 Aug; 151(2):855-9. doi: 10.1128/jb.151.2.855-859.1982" |
