Plasmid conjugative

Basta T, A Keck, J Klein, A Stolz (2004) Detection and characterization of conjugative plasmids in xenobiotic-degrading Sphingomonas strains. J Bacteriol 186 3862-3872. 

Junker F, AM Cook (1997) Conjugative plasmids and the degradation of arylsulfonates in Comamonas testos-teroni. Appl Environ Microbiol 63 2403-2410. 

Pheromone-Responding Conjugative Plasmids in Enterococcus faecalis 316... 

The enterococcal, conjugative, virulence plasmids encoding a mating response to a peptide sex pheromone have been known for many years. About 30 years ago the first conjugative plasmid (pADl) was identified in a clinical isolate of E. faecalis " and several others have been found since (Table 4). 

Table 4 Conjugal plasmids and their peptide pheromones in Enterococcus faecalis ...

Yano, K. Nishi, T. (1980). pKJl, a naturally occurring conjugative plasmid coding for toluene degradation and resistance to streptomycin and sulfonamides. Journal of Bacteriology, 143, 552—60. 

Resistance can emerge by mutation, though more commonly it is due to plasmid-encoded trimethoprim-resistant dihydrofolate reductases. These resistant enzymes may be located within transposons on conjugative plasmids that exhibit a broad host range, accounting for rapid and widespread dissemination of trimethoprim resistance among numerous bacterial species. 

The first example of chemical communication in low-GC Gram-positive bacteria was discovered in 1978 by Dunny, Clewell and their colleagues.93 It was found that conjugative plasmid transfer of Enterococcus faecalis was induced by a chemical substance, termed sex pheromone, which is secreted from plasmid-free recipient cells. Several years later, the structure of the sex pheromone was elucidated to be an oligopeptide by Suzuki et al Since this discovery, a variety of cell-to-cell communication events in Gram-positive bacteria have been found to be mediated by peptidic substances.95-97... 

Figure 8 Structures of nonmodified oligopeptide signal molecules mediating intraspecies cell-to-cell communication in Gram-positive bacteria, (a) Peptide sex pheromones and their inhibitors involved in the regulation of conjugative plasmid transfer in Enterococcus faecalis. (b) Competence- and sporulation-stimulating factors of Bacillus subtilis.

Figure 9 Sex pheromone signaling leading to conjugative plasmid transfer in Enterococcus faecalis. Sex pheromone (cX) is encoded in the N-terminal leader moiety of lipoprotein. The leader peptide is cleaved off after the translocation of lipoprotein and further processed to generate the pheromone, which is eventually excreted. The secreted pheromone is reimported into the plasmid-donor cell and bound to TraA, which is a transcriptional regulator. Eventually, aggregation substance is induced on the donor cell surface, which leads to plasmid transfer to recipient cell.

Falbo V, Carattoli A, Tosini F, Pezzella C, Dionisi AM, Luzzi I. Antibiotic resistance conferred by a conjugative plasmid and a class I integron in Vibrio cholerae 01 El Tor strains isolated in Albania and Italy. Antimicrob Agents Chemother 1999 43(3) 693-6. 

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