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Chapter 7 : Conjugation and Genetic Exchange in Enterococci

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Abstract:

The medical importance of the enterococci is closely related to the propensity of these organisms to participate in the horizontal transfer of determinants for antibiotic resistance and virulence. Conjugative plasmids in enterococci tend to fall into two main groups. Members of one group encode recognition of recipient-produced peptide pheromones that initiate the mating process; the others do not make use of such signals. The pheromone-responding plasmids usually transfer efficiently in broth (liquid) matings, whereas the others transfer relatively poorly under these conditions. An exception is pMGl, a resistance plasmid in that transfers well in broth despite the apparent absence of a pheromone system. Those plasmids that make use of sex pheromones (e.g., pADl and pCFlO) thus far appear to exhibit a narrow host range—primarily and closely related species-although information on this point is very limited. A partial list of pheromone-responding plasmids is presented in this chapter. The formation of mating aggregates relates to the induction of a protein "aggregation substance" (AS), which appears extensively over the donor surface and binds to "enterococcal binding substance" (EBS) on the recipient surface. Conjugative transposons are particularly common in enterococci and streptococci and play an important role in the dissemination of antibiotic resistance in these organisms. It is likely that the enterococci play a significant role as a hardy facultative reservoir of genetic information available to a variety of other genera.

Citation: Clewell D, Dunny G. 2002. Conjugation and Genetic Exchange in Enterococci, p 265-300. In Gilmore M, Clewell D, Courvalin P, Dunny G, Murray B, Rice L (ed), The Enterococci. ASM Press, Washington, DC. doi: 10.1128/9781555817923.ch7

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Figures

Image of Figure 1
Figure 1

Expression of pCF10-encoded surface proteins observed by field emission scanning electron microscopy. The cells shown are from cultures of isogenic strains of carrying either the shuttle vector pWM402 (right panel) or pINY1801 (a chimeric plasmid containing the cloned [surface exclusion protein, Sec10]) and [aggregation substance, Asc10] genes of pCFlO cloned into pWM402). The latter plasmid confers constitutive expression of Asc10 and Sec10 on its host cell ( ). The cells were preserved by a cryofixation procedure similar to that described by Erlandsen et al. ( ). Note the smooth appearance of the bacterial cell surface (right panel) and surface display of the plasmid-encoded proteins as discrete entities with well-defined structural features. Micrographs were kindly supplied by Dr. Stanley Erlandsen, University of Minnesota.

Citation: Clewell D, Dunny G. 2002. Conjugation and Genetic Exchange in Enterococci, p 265-300. In Gilmore M, Clewell D, Courvalin P, Dunny G, Murray B, Rice L (ed), The Enterococci. ASM Press, Washington, DC. doi: 10.1128/9781555817923.ch7
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Image of Figure 2
Figure 2

Production, release, and sensing of enterococcal peptides at the cell surface. In the recipient cell shown at the left, the lipoprotein signal peptide is processed by Eep in the cell membrane and the mature pheromone is secreted to the exterior, where it can diffuse into the extracellular medium or remain associated with the cell wall. The plasinid-containing donor cell depicted on the right can bind exogenous pheromone via the plasmid-encoded, peptide-specific binding protein (PrgZ/TraC) and use the chromosomal-encoded Opp system to import the peptide. This cell retains the ability to produce pheromone; however, the plasmid-encoded regulatory protein (PrgY/TraB) in the membrane reduces the endogenous pheromone, thus blocking an autocrine loop where endogenous pheromone could be immediately bound and reinternalized by the producing cell. In addition, the inhibitor peptide is secreted into the growth medium where it serves to neutralize any pheromone released by the same cell. The level of inhibitor secreted seems to be just enough to neutralize any endogenous peptide, while still allowing for exquisite sensitivity to exogenous pheromone.

Citation: Clewell D, Dunny G. 2002. Conjugation and Genetic Exchange in Enterococci, p 265-300. In Gilmore M, Clewell D, Courvalin P, Dunny G, Murray B, Rice L (ed), The Enterococci. ASM Press, Washington, DC. doi: 10.1128/9781555817923.ch7
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Image of Figure 3
Figure 3

Comparison of pADl, pCF10, pPDl, and pAM373 in regions that include determinants that relate to regulation of the pheromone response. ORFs indicated by similar colors are homologues in the different plasmids.

Citation: Clewell D, Dunny G. 2002. Conjugation and Genetic Exchange in Enterococci, p 265-300. In Gilmore M, Clewell D, Courvalin P, Dunny G, Murray B, Rice L (ed), The Enterococci. ASM Press, Washington, DC. doi: 10.1128/9781555817923.ch7
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Image of Figure 4
Figure 4

Model showing the control circuitry for the pADl and pCFlO pheromone response. P is a primary promoter that is active to some extent even in the uninduced state, giving rise to m3 (for pADl) and Qs (for pCF10), which are terminated at t/IRS1 (noted as 1 in the figure). Induction results in up-regulation from P, which gives rise to significant amounts of m3* (for pADl) and QL (for pCF10), which are terminated at t/IRS2 (noted as 2 in the figure). Induction also results in extension through t/IRS2 and into regions that include determinants that positively regulate conjugation genes. The positive regulators appear to differ significantly for the two plasmids. The short component of the speckled transcript represents mD (for pADl) and Qa (for pCF10), which are expressed under the Pa promoter and, at least in the case of pADl, enhance termination at t. Pa is also believed to govern expression of TraA/PrgX, which negatively regulates expression from P and is able to bind to pheromone. Expression from Pa is down-regulated upon induction.

Citation: Clewell D, Dunny G. 2002. Conjugation and Genetic Exchange in Enterococci, p 265-300. In Gilmore M, Clewell D, Courvalin P, Dunny G, Murray B, Rice L (ed), The Enterococci. ASM Press, Washington, DC. doi: 10.1128/9781555817923.ch7
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Image of Figure 5
Figure 5

Map of the conjugative transposon showing ORFs believed to be related to conjugation. The transposon is approximately 18 kb in length. Apparent relationships with genes/ORFs in the database are noted.

Citation: Clewell D, Dunny G. 2002. Conjugation and Genetic Exchange in Enterococci, p 265-300. In Gilmore M, Clewell D, Courvalin P, Dunny G, Murray B, Rice L (ed), The Enterococci. ASM Press, Washington, DC. doi: 10.1128/9781555817923.ch7
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References

/content/book/10.1128/9781555817923.chap7
1. An, E. Y.,, and D. B. Clewell. 2002. Identification of the cADl sex pheromone precursor in Enterococcus faecalis. J. Bacterial. 184, in press.
2. An, F. Y.,, and D. B. Clewell. 1994. Characterization of the determinant (traB) encoding sex pheromone shutdown by the hemolysin/bacteriocin plasmid pADl in Enterococcus faecalis. Plasmid 31:215221.
3. An, F. Y.,, and D. B. Clewell. 1997. The origin of transfer (onT) of the Enterococcal, pheromone-responding, cytolysin plasmid pADl is located within the repA determinant. Plasmid 37:8794.
4. An, F. Y.,, M. C. Sulavik,, and D. B. Clewell. 1999. Identification and characterization of a determinant (eep) on the Enterococcus faecalis chromosome that is involved in production of the peptide sex pheromone cADl. J. Bacterial. 181: 59155921.
5. 4a. Antiporta, M. H.,, and G. M. Dunny. 2002. ccFA, the genetic determinant for the cCFlO peptide pheromone in Enterococcus faecalis OG1RF. J. Bacteriol. 184:11551162.
5. Ayoubi, P.,, A. O. Kilic,, and M. N. Vijayakumar. 1991. Tn5253, the pneumococ-cal ω (cat tet) BM6001 element, is a composite structure of two conjugative transposons Tn5251 and Tn5252. J. Bacteriol. 173:16171622.
6. Bae, T. 2000. The role of PrgX and Qa RNA in pheromone-inducible prgB expression in enterococcal conjugative plasmid pCF10. Ph.D. thesis. University of Minnesota, Minneapolis, MN.
7. Bae, T.,, S. Clerc-Bardin,, and G. M. Dunny. 2000. Analysis and expression of prgX, a key negative regulator of the transfer of the Enterococcus faecalis pheromone-inducible plasmid pCFlO. J. Mol. Biol. 297:861875.
8. Bae, T.,, and G. M. Dunny. 2001. Dominant-negative mutants of prgX: evidence for a role for PrgX dimerization in negative regulation of pheromone-inducible conjugation. Mol. Microbiol. 39:13071320.
10. 8a. Bae, T.,, B. Kozlowicz,, and G. M. Dunny. 2002. Two targets in pCFlO DNA for PrgX binding: their role in production of Qa and prgX mRNA and in regulation of pheromone-inducible conjugation. J. Mol. Biol. 315:9951007.
9. Bastos, M. C. F.,, K. Tanimoto,, and D. B. Clewell. 1997. Regulation of transfer of the Enterococcus faecalis pheromone-responding plasmid pADl: temperature-sensitive transfer mutants and identification of a new regulatory determinant, traD. J. Bacteriol. 179:32503259.
10. Bastos, M. C. F,, H. Tomita,, K. Tanimoto,, and D. B. Clewell. 1998. Regulation of the Enterococcus faecalis pADl-related sex pheromone response: analyses of traD expression and its role in controlling conjugation. Mol. Microbiol. 30:381392.
11. Sensing, B. A.,, and G. M. Dunny. 1993. Cloning and molecular analysis of genes affecting expression of binding substance, the recipient-encoded receptor(s) mediating mating aggregate formation in Enterococcus faecalis. J. Bacteriol. 175:74217429.
12. Bensing, B. A.,, and G. M. Dunny. 1997. Pheromone-inducible expression of an aggregation protein in Enterococcus faecalis requires interaction of a plasmid-encoded RNA with components of the ribosome. Mol. Microbiol. 24:295308.
13. Bensing, B. A.,, D. A. Manias,, and G. M. Dunny. 1997. Pheromone cCFlO and plasmid pCFlO-encoded regulatory molecules act post-transcriptionally to activate expression of downstream conjugation functions. Mol. Microbiol. 24:285294.
14. Bensing, B. A.,, B. J. Meyer,, and G. M. Dunny. 1996. Sensitive detection of bacterial transcription initiation sites and differentiation from RNA processing sites in the pheromone-induced plasmid transfer system of Enterococcus faecalis. Proc. Nat. Acad. Sci. USA 93:77947799.
15. Berg, T.,, N. Firth,, S. Apisiridej,, A. Hettiaratchi,, A. Leelaporn,, and R. A. Skur-ray. 1998. Complete nucleotide sequence of pSK41: evolution of staphylococcal conjugative multiresistance plasmids. J. Bacteriol. 180:43504359.
16. Berg, T.,, N. Firth,, and R. A. Skurray,. 1997. Enterococcal pheromone-like activity derived from a lipoprotein signal peptide encoded by a Staphylococcus aureus plasmid, p. 10411044. In T. Horaud,, M. Sicard,, A. Bouve,, and H. de Montelos (eds.), Streptococci and the Host. Plenum Press, New York, N.Y.
17. Borderon, E.,, G. Bieth,, and T. Horodniceanu. 1982. Genetic and physical studies of Streptococcus faecalis hemolysin plasmids. FEMS Microbiol. Lett. 14:5155.
18. Brown, M. S.,, J. Ye,, R. B. Rawson,, and J. L. Goldstein. 2000. Regulated intra-membrane proteolysis; a control mechanism conserved from bacteria to humans. Cell 100:391398.
19. Bryan, E. M.,, J. H. Staddon,, and G. M. Dunny. Manuscript in preparation.
20. Burdett, V. 1986. Streptococcal tetracycline resistance mediated at the level of protein synthesis. J. Bacteriol. 165:564569.
21. Burdett, V. 1990. Nucleotide sequence of the tet(M) gene of Tn926. Nucleic Acids Res. 18:6137.
22. Burtram, J.,, M. Strata,, and P. Durre. 1991. Natural transfer of conjugative trans-poson Tn926 between gram-positive and gram-negative bacteria, J. Bacteriol. 173: 443448.
23. Buttaro, B. A.,, M. H. Antiporta,, and G. M. Dunny. 2000. Cell-associated pheromone peptide (cCFlO) production and pheromone inhibition in Enterococcus faecalis. J. Bacteriol. 182:49264933.
24. Buttaro, B. A.,, A. Colwell,, D. A., Manias,, and G. M. Dunny. Submitted for publication.
25. Carias, L. L.,, S. D. Rudin,, C J. Donskey,, and L. B. Rice. 1998. Genetic linkage and cotransfer of a novel, vanB-containing transposon (Tn53#2) and a low-affinity penicillin-binding protein 5 gene in a clinical vancomycin-resistant Enterococcus faecium isolate. J. Bacteriol. 180:44264434.
26. Celli, J.,, C. Poyart,, and R. Trieu-Cuot. 1997. Use of an excision reporter plasmid to study the intracellulair mobility of the conjugative transposon Tn916 in gram-positive bacteria. Microbiology 143:12531261.
27. Celli, J.,, and P. Trieu-Cuot 1998. Circularization of Tn916 is required for expression of the transposon-encoded transfer functions: characterization of long tetracycline-inducible transcripts reading through the attachment site. Mol Microbiol. 28:103117.
28. Chow, J. W.,, L. A. Thai,, M. B. Perri,, J. A. Vazquez,, S. M. Donabedian,, D. B. Clewell,, and M. J. Zervos. 1993. Plasmid-associated hemolysin and aggregation substance production contributes to virulence in experimental enterococcal endocarditis. Antimicrob. Agents Chemother. 37:24742477.
29. Christie, P. J.,, S. M. Kao,, J. C. Adsit,, and G. M. Dunny. 1988. Cloning and expression of genes encoding pheromone-inducible antigens of Enterococcus (Streptococcus) faecalis. J. Bacteriol. 170:51615168.
30. Christie, P. J.,, R. Z. Korman,, S. A. Zahler,, J. C. Adsit,, and G. M. Dunny. 1987. Two conjugation systems associated with Streptococcus faecalis plasmid pCFlO: identification of a conjugative transposon that transfers between S. faecalis and Bacillus subtilis. J. Bacteriol 169:25292536.
31. Chung, J. W.,, B. A. Bensing,, and G. M. Dunny. 1995. Genetic analysis of a region of the Enterococcus faecalis plasmid pCF10 involved in positive regulation of conjugative transfer functions, J. Bacteriol 177:21072117.
32. Chung, J. W.,, and G. M. Dunny. 1992. Cis-acting, orientation-dependent, positive control system activates pheromone-inducible conjugation functions at distances greater than 10 kilobases upstream from its target in Enterococcus faecalis. Proc. Natl Acad. Set USA 89:90209024.
33. Chung, J. W.,, and G. M. Dunny. 1995. Transcriptional analysis of a region of the Enterococcus faecalis plasmid pCFlO involved in positive regulation of conjugative transfer functions, J. Bacteriol 177:21182124.
34. Clewell, D. B. 1981. Plasmids, drug resistance, and gene transfer in the genus Streptococcus. Microbiol Rev. 45:401436.
35. Clewell, D. B. 1990. Movable genetic elements and antibiotic resistance in en-terococci. Eur. J. Clin. Microbiol. Infect. Dis. 9:90102.
36. Clewell, D. B. 1993. Bacterial sex pheromone-induced plasmid transfer. Cell 73: 912.
39. 37a. Clewell, D. B., 1998. Conjugative transposons, p. 130139. In F. J. deBrijn,, J. R. Lupinski,, G. M. Weinstock (éd.), Bacterial Genomes, Physical Structure and Analysis. Chapman Hall, New York, N.Y.
37. Clewell, D. B., 1993. Sex pheromones and the plasmid-encoded mating response in Enterococcus faecalis, p. 349367. In D. B. Clewell (ed.), Bacterial Conjugation. Plenum Press, New York, N.Y.
38. Clewell, D. B., 1999. Sex pheromone systems in enterococci, p. 4765. In G. M. Dunny, and S. C. Winans (éd.), Cell-Cell Signaling in Bacteria. ASM Press, Washington, D.C.
39. Clewell, D. B.,, F. Y. An,, S. F. Flannagan,, M. Antiporta,, and G. M. Dunny. 2000. Enterococcal sex pheromone precursors are part of signal sequences for surface lipoprotéine. Mol. Microbiol 35:246247.
40. Clewell, D. B.,, F. Y. An,, B. A. White,, and C. Gawron-Burke. 1985. Streptococcus faecalis sex pheromone (cAM373) also produced by Staphylococcus aureus and identification of a conjugative transposon (Tn918). J. Bacteriol 162:12121220.
41. Clewell, D. B.,, and B. L. Brown. 1980. Sex pheromone cADl in Streptococcus faecalis: induction of a function related to plasmid transfer, J. Bacteriol. 143:10631065.
42. Clewell, D. B.,, and S. E. Flannagan,. 1993. The conjugative transposons of gram positive bacteria, p. 369l393. In D. B. Clewell (éd.), Bacterial Conjugation. Plenum Press, New York, N.Y.
43. Clewell, D. B.,, S. E. Flannagan,, Y. Ike,, J. M. Jones,, and C. Gawron-Burke. 1988. Sequence analysis of termini of conjugative transposon Tn916. J. Bacteriol. 170:30463052.
44. Clewell, D. B.,, S. E. Flannagan,, and D. D. Jaworski. 1995. Unconstrained bacterial promiscuity: the Tn916-Tn2545 family of conjugative transposons. Trends Microbiol. 3:229236.
45. Clewell, D. B.,, S. E. Flannagan,, L. A. Zitzow,, Y. A. Su,, P. He,, E. Senghas,, and K. W. Weaver,. 1991. Properties of conjugative transposon Tn916, p. 3944. In G. M. Dunny,, P. Cleary,, and L. McKay (ed.), Genetics and Molecular Biology of Streptococci, Lactococci, and Enterococci. American Society for Microbiology, Washington, D.C.
46. Clewell, D. B.,, and C. Gawron-Burke. 1986. Conjugative transposons and the dissemination of antibiotic resistance in streptococci. Annu. Rev. Microbiol. 40: 635659.
47. Clewell, D. B.,, L. T. Pontius,, F. Y. An,, Y. Ike,, A. Suzuki,, and J. Nakayama. 1990. Nucleotide sequence of the sex pheromone inhibitor (iAD1) determinant of Enterococcus faecalis conjugative plasmid pAD1. Plasmid 24:156161.
48. Clewell, D. B.,, P. K. Tomich,, M. C. Gawron-Burke,, A. E. Franke,, Y. Yagi,, and F. Y. An. 1982. Mapping of Streptococcus faecalis plasmids pAD1 and pAD2 and studies relating to transposition of Tn917. J. Bacteriol. 152:12201230.
49. Clewell, D. B.,, and K. E. Weaver. 1989. Sex pheromones and plasmid transfer in Enterococcus faecalis (a review). Plasmid 21:175184.
50. Clewell, D. B.,, Y. Yagi,, and B. Bauer. 1975. Plasnüd-determined tetracycline resistance in Streptococcus faecalis: evidence for gene amplification during growth in presence of tetracycline. Proc. Natl. Acad. Set. USA 72:17201724.
51. Clewell, D. B.,, Y. Yagi,, G. M. Dunny,, and S. K. Schultz. 1974. Characterization of three plasmid deoxyribonucleic acid molecules in a strain of Streptococcus faecalis: identification of a plasmid detenrtining erythromycin resistance. J. Bacteriol. 117:283289.
52. Clewell, D. B.,, Y. Yagi,, Y. Ike,, R. A. Craig,, B. L. Brown,, and F. An,. 1982. Sex pheromones in Streptococcus faecalis: multiple pheromone systems in strain DS5, similarities of pAD1 and pAMβ1, and mutants of pAD1 altered in conjugative properties, p. 97100. In D. Schlessinger (éd.), Microbiology1982. American Society for Microbiology, Washington, D.C.
53. De Boever, E. H. 2001. Genetic and transcriptional analyses of the pheromone response of the Enterococcus faecalis plasmid AM373. Ph.D. dissertation. The University of Michigan, Ann Arbor.
54. De Boever, E. H.,, and D. B.. Clewell. 2001. The Enterococcus faecalis pheromone-responsive plasmid pAM373 does not encode an entry exclusion function. Plasmid 45:5760.
55. De Boever, E. H.,, D. B. Clewell,, and C. M. Fraser. 2000. Enterococcus faecalis conjugative plasmid pAM373: complete nucleotide sequence and genetic analyses of sex pheromone response. Mol. Microbiol. 37:13271341.
56. de Lencastr, H.,, A. E. Brown,, M. Chung,, D. Armstrong,, and A. Tomasz. 1999. Role of transposon Tn5482 in the epidemiology of vancomycin-resistant Enterococcus f aecium in the pediatrie oncology unit of a New York City hospital. Microb. Drug Resist. 5:113129.
57. Delver, E. P.,, V. U. Kotova,, G. B. Zavilgelsky,, and A. A. Belogurov. 1991. Nucleotide sequence of the gene (ara) encoding the antirestriction protein of plasmid colIb-P9. J. Bacteriol. 173:58875892.
58. Doucet-Populaire, F.,, P. Trieu-Cuot,. I. Dosbaa,, A. Andremont.,, and R. Cour-valin. 1991. Inducible transfer of conjugative transposon Tn1545 from Enterococcus faecalis to Listeria monocytogenes in the digestive tracts of gnotobiotic mice. Antimicrob. Agents Chemother. 35:185187.
59. Dunny, G. M. 1990. Genetic functions and cell-cell interactions in the phero-mone-inducible plasmid transfer system of Enterococcus faecalis. Mol. Microbiol. 4:689696.
60. Dunny, G. M. 1991. Mating interactions in gram-positive bacteria, p. 933. In M. Dworkin (éd.), Microbiol Cell-Cell Interactions. American Society for Microbiology, Washington, D.C.
61. Dunny, G. M.,, M. H. Antiporta,, and H. Hirt. 2001. Peptide pheromone-induced transfer of plasmid pCF10 in Enterococcus faecalis: probing the genetic and molecular basis for specificity of the pheromone response. Peptides 22:15291539.
62. Dunny, G. M.,, B. L. Brown,, and D. B. Clewell. 1978. Induced cell aggregation and mating in Streptococcus faecalis: evidence for a bacterial sex pheromone. Proc. Natl. Acad. Sci. USA 75:34793483.
63. Dunny, G. M.,, and D. B. Clewell. 1975. Transmissible toxin (hemolysin) plasmid in Streptococcus faecalis and its mobilization of a noninfectious drug resistance plasmid. J. Bacteriol. 124:784790
64. Dunny, G. M.,, R. A. Craig,, R. L. Carron,, and D. B. Clewell. 1979. Plasmid transfer in Streptococcus faecalis: production of multiple sex pheromones by recipients. Plasmid 2:454465.
65. Dunny, G. M.,, C. Funk,, and J. Adsit. 1981. Direct stimulation of the transfer of antibiotic resistance by sex pheromones in Streptococcus faecalis. Plasmid 6:270278.
66. Dunny, G. M.,, and B. A. B. Leonard. 1997. Cell-cell communication in gram-positive bacteria. Annu. Rev. Microbiol. 51:527564.
67. Dunny, G. M.,, B. A. B. Leonard,, and P. J. Hedberg. 1995. Pheromone-inducible conjugation in Enterococcus faecalis: interbacterial and host-parasite chemical communication. J. Bactenol. 177:871876.
68. Dunny, G.,, M. Yuhasz,, and E. Ehrenfeld. 1982. Genetic and physiological analysis of conjugation in Streptococcus faecalis. J. Bacteriol. 151:855859.
69. Dunny, G. M.,, D. L. Zimmerman,, and M. L. Tortorello. 1985. Induction of surface exclusion by Streptococcus faecalis sex pheromones: use of monoclonal antibodies to identify an inducible surface antigen involved in the exclusion process. Proc. Natl. Acad. Sci. USA 82:85828586.
70. Ehrenfeld, E. E.,, and D. B. Clewell. 1987. Transfer functions of the Streptococcus faecalis plasmid pAD1: organization of plasmid DNA encoding response to sex pheromone. J. Bacteriol. 169:34733481.
71. Ehrenfeld, E. E.,, R. E. Kessler,, and D. B. Clewell. 1986. Identification of pheromone-induced surface proteins in Streptococcus faecalis and evidence of a role for lipoteichoic acid in formation of mating aggregates. J. Bacteriol. 168: 612.
72. Ember, J. A.,, and T. E. Hugli. 1989. Characterization of the human neutrophil response to sex pheromones from Streptococcus faecalis. Am. J. Pathol. 134:797805.
73. Erlandsen, S. L., C. Frethem, and Y. Chen. 2000. Field emission scanning electron microscopy (FESEM) entering the 21st century: nanometer resolution and molecular topography of cell structure. J. Histotechnol. 23:249259.
74. Firth, N.,, P. D. Fink,, L. Johnson,, and R. A. Skurray. 1994. A lipoprotein signal peptide encoded by the staphylococcal conjugative plasmid pSK41 exhibits an activity resembling that of Enterococcus faecalis pheromone cADl. J. Bacteriol. 176: 58715873.
75. Flannagan, S. E.,, and D. B. Clewell. 2002. Identification and characterization of genes encoding sex pheromone cAM373 activity in Enterococcus faecalis and Staphylococcus aureus. Mol. Microbiol., in press.
76. Flannagan, S. E.,, and D. B. Clewell. 1991. Conjugative transfer of Tn916 in Enterococcus faecalis: trans activation of homologous transposons, J. Bacteriol. 173: 71367141.
77. Flannagan, S. E.,, L. A. Zitzow,, Y. A. Su,, and D. B. Clewell. 1994. Nucleotide sequence of the 18-kb conjugative transposon Tn916 from Enterococcus faecalis. Plasmid 32:350354.
78. Francia, M. V.,, and D. B. Clewell. 2001. Identification of new oriT sites on the pheromone-responding Enterococcus faecalis plasmids pADl and pAM373. ASM Conference on Cell-Cell Communication, Snowbird, Utah.
79. Francia, M. V.,, W. Haas,, R. Wirth,, E. Samberger,, A. Muscholl-Silberhorn,, M. S. Gilmore,, Y. Ike,, K. E. Weaver,, F. Y. An,, and D. B. Clewell. 2001. Completion of the nucleotide sequence of the Enterococcus faecalis conjugative virulence plasmid pADl and identification of a second transfer origin. Plasmid 46:117127.
80. Franke, A. E.,, and D. B. Clewell. 1981. Evidence for a chromosome-borne resistance transposon (Tn916) in Streptococcus faecalis that is capable of "conjugal" transfer in the absence of a conjugative plasmid. J. Bacterial. 145:494502.
81. Franke, A. E.,, G. M. Dunny,, B. L. Brown,, F. An,, D. R. Oliver,, S. P. Damle,, and D. B. Clewell,. 1978. Gene transfer in Streptococcus faecalis: evidence for the mobilization of chromosomal determinants by transmissible plasmids, p. 4547. In D. Schlessinger (éd.), Microbiology1978. American Society for Microbiology, Washington, D.C.
82. Fujimoto, S.,, and D. B. Clewell. 1998. Regulation of the pADl sex pheromone response of Enterococcus faecalis by direct interaction between the cADl peptide mating signal and the negatively regulating, DNA-binding TraA protein. Proc. Natl. Acad. Set. USA 95:64306435.
83. Fujimoto, S.,, and Y. Ike. 2000. Plasmid-specific DNA binding of TraAs and PrgX of Enterococcus faecalis plasmids pAD1, pPD1, and CF10. First International ASM Conference on Enterococci, Banff, Canada.
84. Fujimoto, S.,, H. Tomita,, E. Wakamatsu,, K. Tanimoto,, and Y. Ike. 1995. Physical mapping of the conjugative bacteriocin plasmid pPD1 of Enterococcus faecalis and identification of the determinant related to the pheromone response, J. Bacteriol. 177:55745581.
85. Galli, D.,, A. Friesenegger,, and R. Wirth. 1992. Transcriptional control of sex-pheromone-inducible genes on plasmid pADl of Enterococcus faecalis and sequence analysis of a third structural gene for (pPDl-encoded) aggregation substance. Mol. Microbiol. 6:12971308.
86. Galli, D.,, F. Lottspeich,, and R. Wirth. 1990. Sequence analysis of Enterococcus faecalis aggregation substance encoded by the sex pheromone plasmid pAD1. Mol. Microbiol. 4:895904.
87. Galli, D.,, and R. Wirth. 1991. Comparative analysis of Enterococcus faecalis sex pheromone plasmids identifies a single homologous DNA region which codes for aggregation substance, J. Bacteriol. 173:30293033.
88. Galli, D.,, R. Wirth,, and G. Wanner. 1989. Identification of aggregation substances of Enterococcus faecalis after induction by sex pheromones. Arch. Microbiol. 151:486490.
89. Gamier, E.,, S. Taourit,, P. Glaser,, P. Courvalin,, and M. Galimand. 2000. Characterization of transposon Tn1549, conferring VanB-type resistance in Enterococcus spp. Microbiology 146:14811489.
90. Gawron-Burke, M. C.,, and D. B. Clewell. 1982. A transposon in Streptococcus faecalis with fertility properties. Nature 300:281284.
91. Gawron-Burke, M. C.,, and D. B. Clewell. 1984. Regeneration of insertionally inactivated streptococcal DNA fragments following excision of Tn916 in Escherichia colt. A strategy for targeting and cloning genes from gram-positive bacteria. J. Bacteriol. 159:214221.
92. Gilmore, M. S.,, R. A. Segarra,, M. C. Booth,, C. P. Bogie,, L. R. Hall,, and D. B. Clewell. 1994. Genetic structure of the Enterococcus faecalis plasmid pAD1-encoded cytolytic toxin system and its relationship to lantibiotic determinants. J. Bacteriol. 176:73357344.
93. Guzman, C. A.,, C. Pruzzo,, M. Plate,, M. C. Guardati,, and L. Calegari. 1991. Serum dependent expression of Enterococcus faecalis adhesins involved in the colonization of heart cells. Microb. Pathog. 11:399409.
94. Handwerger, S.,, M. J. Pucci,, and A. Kolokathis. 1990. Vancomycin resistance is encoded on a pheromone response plasmid in Enterococcus faecium 228. Antimicrob. Agents Chemother. 34:358360.
95. Handwerger, S.,, and J. Skoble. 1995. Identification of chromosomal mobile element conferring high-level vancomycin resistance in Enterococcus faecium. Antimicrob. Agents Chemother. 39:24462453.
96. Heath, D. G.,, F. Y. An,, K. E. Weaver,, and D. B. Clewell. 1995. Phase variation of Enterococcus faecalis pAD1 conjugation functions relates to changes in iteron sequence region. J. Bacteriol. 177:54535459.
97. Heaton, M. P.,, L. E Discotto,, M. J. Pucci,, and S. Handwerger. 1996. Mobilization of vancomycin resistance by transposon-mediated fusion of a VanA plasmid with an Enterococcus faecium sex pheromone-response plasmid. Gene 171: 917.
98. Heaton, M. P.,, and S. Handwerger. 1995. Conjugative mobilization of a vancomycin resistance plasmid by a putative Enterococcus faecium sex pheromone response plasmid. Microb. Drug. Resist. 1:177183.
99. Hedberg, P. J.,, B. A. B. Leonard,, R. E. Ruhfel,, and G. M. Dunny. 1996. Identification and characterization of the genes of Enterococcus faecalis plasmid pCF10 involved in replication and in negative control of pheromone-inducible conjugation. Plasmid 35:4657.
100. Hinerfeld, D.,, and G. Churchward. 2001. Specific binding of integrase to the origin of transfer (oriT) of the conjugative transposon Tn916. J. Bacteriol. 183: 29472951.
101. Hirt, H.,, S. L. Erlandsen,, and G. M. Dunny. 2000. Heterologous inducible expression of Enterococcus faecalis pCFlO aggregation substance AsclO in Lactococcus lactis and Streptococcus gordonii contributes to cell hydrophobicity and adhesion to fibrin. J. Bacteriol. 182:22992306.
102. Hirt, H.,, P. M. Schlievert,, and G. M. Dunny. 2002. In vivo induction of virulence and antibiotic resistance transfer in Enterococcus faecalis mediated by the sex pheromone-sensing system of pCFlO. Infect. Immun. 70:716723.
103. Hirt, H.,, G. Wanner,, D. Galli,, and R. Wirth. 1993. Biochemical, immunologi-cal and ultrastructural characterization encoded by Enterococcus faecalis sex-pheromone plasmids. Eur. J. Biochem. 211:711716.
104. Hirt, H.,, R. Wirth,, and A. Muscholl. 1996. Comparative analysis of 18 sex pheromone plasmids from Enterococcus faecalis: detection of a new insertion element on pPD1 and implications for the evolution of this plasmid family. Molec. Gen. Genet. 252:640647.
105. Hofner, H.,, R. Wirth,, R. Marre,, G. Wanner,, and E. Straube. 1995. Subinhibitory concentrations of daptomycin enhance adherence of Enterococcus faecalis to in vitro cultivated renal tubuloepithelial cells and induce a sex pheromone plasmid-encoded adhesin. Med. Microbiol. Lett. 4:140149.
106. Horaud, T.,, G. de Cespedes,, D. Clermont,, E David, and F. Delbos. 1991. Variability of chromosomal genetic elements in streptococci, p. 1620. In G. M. Dunny,, P. P. Cleary,, and L. L. McKay (ed), Genetics and Molecular Biology of Streptococci, hactococci, and Enterococci. American Society for Microbiology, Washington, D.C.
107. Horaud, T.,, C. Le Bouguenec,, and K. Pepper. 1985. Molecular genetics of resistance to macrolides, lincosamides and streptogramin B (MLS) in streptococci. J. Antimicrob. Chemother. 16:111135.
108. Horn, T.,, J. Nakayama,, S. Sakuda,, and H. Nagasawa. 2000. Analysis of tran-scriptional control by sex pheromone receptor, TraA, in Enterococcus faecalis. First International ASM Conference on Enterococci, Banff, Canada.
109. Huycke, M. M.,, M. S. Gilmore,, B. D. Jett,, and J. L. Booth. 1992. Transfer of pheromone-inducible plasmids between Enterococcus faecalis in the Syrian hamster gastrointestinal tract. J. Infect. Dis. 166:11881191.
110. Huycke, M. M.,, D. E Sahm,, and M. S. Gilmore. 1998. Multiple-drug resistant enterococci: the nature of the problem and an agenda for the future. Emerg. Infect. Dis. 4:239249.
111. Ike, Y.,, and D. B. Clewell. 1984. Genetic analysis of the pADl pheromone response in Streptococcus faecalis, using transposon Tn927 as an insertional mutagen. J. Bacterial. 158:777783.
112. Ike, Y.,, and D. B. Clewell. 1992. Evidence that the hemolysin/bacteriocin phe-notype of Enterococcus faecalis subsp. zymogenes can be determined by plasmids in different incompatibility groups as well as by the chromosome. J. Bacterial. 171:81728177.
113. Ike, Y.,, R. C. Craig,, B. A. White,, Y. Yagi,, and D. B. Clewell. 1983. Modification of Streptococcus faecalis sex pheromones after acquisition of plasmid DNA. Proc. Natl. Acad. Sci. USA 80:53695373.
114. Ike, Y.,, S. E. Flannagan,, and D. B. Clewell. 1992. Hyperhemolytic phenomena associated with insertions of Tn916 into the hemolysin determinant of Enterococcus faecalis plasmid pADl. J. Bacteriol. 174:18011809.
115. Ike, Y.,, H. Hashimoto,, and D. B. Clewell. 1984. Hemolysin of Streptococcus faecalis subspecies zymogenes contributes to virulence in mice. Infect. Immun. 45: 528530.
116. Ike, Y.,, H. Hashimoto,, and D. B. Clewell. 1987. High incidence of hemolysin production by Enterococcus (Streptococcus) faecalis strains associated with human parenteral infections. J. Clin. Microbiol. 25:15241528.
117. Ike, Y.,, K. Tanimoto,, H. Tomita,, K. Takeuchi,, and S. Fujimoto. 1998. Efficient transfer of the pheromone-independent Enterococcus faecium plasmid pMG1 (Gmr) (65.1 kilobases) to Enterococcus strains during broth mating, J. Bacteriol. 180:48864892.
118. Jacob, A. E.,, G. I. Douglas,, and S. J. Hobbs. 1975. Self-transferable plasmids determining the hemolysin and bacteriocin of Streptococcus faecalis var. zymogenes. J. Bacteriol. 121:863872.
119. Jacob, A. E.,, and S. Hobbs. 1974. Conjugal transfer of plasmid-borne multiple antibiotic resistance in Streptococcus faecalis var. zymogenes. J. Bacteriol. 117:360372.
120. Jaworski, D. D.,, and D. B. Clewell. 1994. Evidence that coupling sequences play a frequency-detenrrining role in conjugative transposition of Tn916 in Enterococcus faecalis. J. Bacteriol. 176:33283335.
121. Jaworski, D. D.,, and D. B. Clewell. 1995. A functional origin of transfer (oriT) on the conjugative transposon Tn916. J. Bacteriol. 177:66446651.
122. Jaworski, D. D.,, S. E. Flannagan,, and D. B. Clewell. 1996. Analyses of traA, int-Tn, and xis-Tn mutations in the conjugative transposon Tn916 in Enterococcus faecalis. Plasmid 36:201208.
123. Jett, B. D.,, H. G. Jensen,, R. E. Nordquist,, and M. S. Gilmore. 1992. Contribution of the pAD1-encoded cytolysin to the severity of experimental Enterococcus faecalis endophthalmitis. Infect. Immun. 60:24452452.
124. Kao, S.-M.,, S. B. Olmsted,, A. S. Viksnins,, J. C. Gallo,, and G. M. Dunny. 1991. Molecular and genetic analysis of a region of plasmid pCF10 containing positive control genes and structural genes encoding surface proteins involved in pheromone-inducible conjugation in Enterococcus faecalis. J. Bactenol. 173:76507664.
125. Kreft, B.,, R. Marre,, U. Schramm,, and R. Wirth. 1992. Aggregation substance of Enterococcus faecalis mediates adhesion to cultured renal tubular cells. Infect. Immun. 60:2530.
126. Le Bouguenec, C.,, G. de Cespedes,, and T. Horaud. 1988. Molecular analysis of a composite chromosomal conjugative element (Tn3701) of Streptococcus pyogenes. J. Bacteriol. 170:39303936.
127. Leonard, B. A. B.,, A. Podbielski,, R J. Hedberg,, and G. M. Dunny. 1996. Enterococcus faecalis pheromone binding protein, PrgZ, recruits a chromosomal oligopeptide permease system to import sex pheromone cCF10 for induction of conjugation. Proc. Natl. Acad. Sci. USA 93:260264.
128. Lowe, A. M.,, R A. Lambert,, and A. W. Smith. 1995. Cloning of an Enterococcus faecalis endocarditis antigen: homology with adhesins from some oral streptococci. Infect. Immun. 63:703706.
129. Manoil, C.,, and J. Baily. 1997. A simple screen for permissive sites in proteins: analysis of Eschenchia coli lac permease. J. Mol. Biol. 267:250263.
130. Maqueda, M.,, R. Quirantes,, I. Martin,, A. Galvez,, M. Martinez-Bueno,, and E. Valdivia. 1997. Chemical signals in gram-positive bacteria: the sex pheromone system in Enterococcus faecalis. Microbiol. Semin. 13:2336.
131. Marra, D.,, B. Pethel,, G. Churchward,, and J. R. Scott. 1999. The frequency of conjugative transposition of Tn916 is not determined by the frequency of excision. J. Bacteriol. 181:54145418.
132. Martinez-Bueno, M.,, A. Galvez,, E. Validivia,, and M. Maqueda. 1990. A transferable plasmid associated with AS-48 production in Enterococcus faecalis. J. Bacteriol. 172:28172818.
133. Martinez-Bueno, M.,, M. Maqueda,, A. Galvez,, B. Samyn,, J. V. Beeumen,, J. Coyette,, and E. Valdivia. 1994. Determination of the gene sequence and the molecular structure of the enterococcal peptide antibiotic AS-48. J. Bacteriol. 176: 63346339.
134. Mcllwraith, M.,, S. Showsh,, and D. B. Clewell. Unpublished.
135. Mori, M.,, A. Isogai,, Y. Sakagami,, M. Fujino,, C. Kitada,, D. B. Clewell,, and A. Suzuki. 1986. Isolation and structure of Streptococcus faecalis sex pheromone inhibitor, iAD1, that is excreted by donor strains harboring plasmid pAD1. Agric. Biol. Chem. 50:539541.
136. Mori, M.,, Y. Sakagami,, Y. Ishii,, A. Isogai,, C. Kitada,, M. Fujino,, J. C. Adsit,, G. M. Dunny,, and A. Suzuki. 1988. Structure of cCF10, a peptide sex pheromone which induces conjugative transfer of the Streptococcus faecalis tetracycline resistance plasmid, pCF10. J. Biol. Chem. 263:1457414578.
137. Mori, M.,, Y. Sakagami,, M. Narita,, A. Isogai,, M. Fuji no,, C. Kitada,, R. Craig,, D. Clewell,, and A. Suzuki. 1984. Isolation and structure of the bacterial sex pheromone, cADl, that induces plasmid transfer in Streptococcus faecalis. FEBS Lett 178:97100.
138. Mori, M.,, H. Tanaka,, Y. Sakagami,, A. Isogai,, M. Fuji no,, C. Kitada,, D. B. Clewell,, and A. Suzuki. 1987. Isolation and structure of the sex pheromone inhibitor, iPD1, excreted by Streptococcus faecalis donor strains harboring plasmid pPD1. J. Bacteriol 169:17471749.
139. Mori, M.,, H. Tanaka,, Y. Sakagami,, A. Isogai,, M. Fujino, C. Kitada, B. A. White, F. Y. An, D. B. Clewell, and A. Suzuki. 1986. Isolation and structure of the Streptococcus faecalis sex pheromone, cAM373. FEBS Lett. 206:6972.
140. Mullany, P.,, M. Pallen,, M. Wilks,, J. R. Stephen,, and S. Tabaqchali. 1996. A group II intron in a conjugative transposon from the gram-positive bacterium, Clostridium difficile. Gene 174:145150.
141. Murray, B. E.,, F. An,, and D. B. Clewell. 1988. Plasmids and pheromone response of the β-lactamase producer Streptococcus (Enterococcus) faecalis HH22. Antimicrob. Agents Chemother. 32:547551.
142. Muscholl-Silberhorn, A. 1998. Analysis of the clumping-mediating domain(s) of sex pheromone plasmid pADl-encoded aggregation substance. Eur. J. Biochem. 258:515520.
143. Muscholl-Silberhorn, A. 1999. Cloning and functional analysis of Asa373, a novel adhesin unrelated to the other sex pheromone plasmid-encoded aggregation substances of Enterococcus faecalis. Mol. Microbiol. 34:620630.
144. Muscholl-Silberhorn, A. 2000. Pheromone-regulated expression of sex pheromone plasmid pADl-encoded aggregation substance depends on at least six upstream genes and a cis-acting, orientation-dependent factor. J. Bacteriol. 182: 38163825.
145. Muscholl, A.,, D. Galli,, G. Wanner,, and R. Wirth. 1993. Sex pheromone plasmid pADl-encoded aggregation substance of Enterococcus faecalis is positively regulated in trans by traE1. Eur. J. Biochem. 214:333338.
146. Muscholl-Silberhorn, A.,, E. Samberger,, and R. Wirth. 1997. Why does Staphylococcus aureus secrete an Enterococcus faecalis-specific pheromone? FEMS Microbiol. Lett. 157:261266.
147. Nakayama, J.,, Y. Abe,, A. Isogai,, and A. Suzuki. 1995. Isolation and structure of the Enterococcus faecalis sex pheromone, cOB1, that induces conjugal transfer of the hemolysin/bacteriocin plasmids, pOBl and pYIl. Biosci. Biotech. Biochem. 59:703705.
148. Nakayama, J.,, D. B. Clewell,, and A. Suzuki. 1995. Targeted disruption of the PD78 (traF) reduces pheromone-inducible conjugal transfer of the bacteriocin plasmid pPD1 in Enterococcus faecalis. FEMS Microbiol. Lett. 128:283288.
149. Nakayama, J.,, G. M. Dunny,, D. B. Clewell,, and A. Suzuki,. 1995. Quantitative analysis for pheromone inhibitor and pheromone shutdown in Enterococcus faecalis, p. 35-38. In J. J. Ferretti,, M. S. Gilmore,, T. R. Klaenhammer,, and F. Brown (eds.), Genetics of Streptococci, Enterococci and Lactococci. Developmental and Biological Standards, vol. 85. Karger, Basel, Switzerland.
150. Nakayama, J.,, S. Igarashi,, H. Nagasawa,, D. B. Clewell,, F. Y. An,, and A. Suzuki. 1996. Isolation and structure of staph-cAM373 produced by Staphylococcus aureus that induces conjugal transfer of Enterococcus faecalis plasmid pAM373. Biosci. Biotech. Biochem. 60:10381039.
151. Nakayama, J.,, Y. Ono,, A. Isogai,, D. B. Clewell,, and A. Suzuki. 1995. Isolation and structure of the sex pheromone inhibitor, ÎAM373, of Enterococcus faecalis. Biosci. Biotech. Biochem. 59:13581359.
152. Nakayama, J.,, R. E. Ruhfel,, G. M. Dunny,, A. Isogai,, and A. Suzuki. 1994. The prgQ gene of the Enterococcus faecalis tetracycline resistance plasmid pCF10 encodes a peptide inhibitor, iCF10. J. Bacteriol 176:20032004.
153. Nakayama, J.,, and A. Suzuki. 1997. Genetic analysis of plasmid-specific pheromone signaling encoded by pPDl in Enterococcus faecalis. Biosci. Biotech. Biochem. 61:17961799.
154. Nakayama, J.,, Y. Takanami,, T. Horii,, S. Sakuda,, and A. Suzuki. 1998. Molecular mechanism of peptide-specific pheromone signaling in Enterococcus faecalis: functions of pheromone receptor TraA and pheromone-binding protein TraC encoded by plasmid pPD1. J. Bacteriol. 180:449456.
155. Nakayama, J.,, K. Yoshida,, H. Kobayashi,, A. Isogai,, D. B. Clewell,, and A. Suzuki. 1995. Cloning and characterization of a region of Enterococcus faecalis plasmid pPDl encoding pheromone inhibitor (ipd), pheromone sensitivity (traC), and pheromone shutdown (traB) genes. J. Bacteriol. 177:55675573.
156. Nes, I. F.,, and V. G. H. Eijsink,. 1999. Regulation of group II peptide bacteriocin synthesis by quorum-sensing mechanisms, p. 175192. In G. M. Dunny,, and S. C. Wïnans (éd.), Cell-Cell Signaling in Bacteria. ASM Press, Washington, D.C.
160. 156a. Netherwood, T.,, R. Bowden,, P. Harrison,, A. G. O'Donnell,, D. S. Parker,, and H. J. Gilbert 1999. Gene transfer in the gastrointestinal tract. Appl. Environ. Microbiol. 65:51395141.
157. Norgren, M.,, and J. R. Scott 1991. The presence of conjugative transposon Tn916 in the recipient strain does not impede transfer of a second copy of the element. J. Bacteriol. 173:319324.
158. Oliver, D. R.,, B. L. Brown,, and D. B. Clewell. 1977. Characterization of plas-mids detennining hemolysin and bacteriocin production in Streptococcus faecalis 5952. J. Bactenol. 130:948950.
159. Oliver, D. R.,, B. L. Brown,, and D. B. Clewell. 1977. Analysis of plasmid de-oxyribonucleic acid in a cariogenic strain of Streptococcus faecalis: an approach to identifying genetic determinants on cryptic plasmids. J. Bacteriol. 130:759765.
160. Olmsted, S. B., G. M. Dunny, S. L. Erlandsen, and C. L. Wells. 1994. A plasmid-encoded surface protein on Enterococcus faecalis augments its internal-ization by cultured epithelial cells. J. Infect. Dis. 170:15491556.
161. Olmsted, S. B.,, S. L. Erlandsen,, G. M. Dunny,, and C. L. Wells. 1993. High-resolution visualization by field emission scanning electron microscopy of Enterococcus faecalis surface proteins encoded by the pheromone-inducible conjugative plasmid pCFlO. J. Bacteriol. 175:62296237.
162. Olmsted, S. B.,, S.-M. Kao,, L. J. van Putte,, J. C. Gallo,, and G. M. Dunny. 1991. Role of the pheromone-inducible surface protein Asc10 in mating aggregate formation and conjugal transfer of the Enterococcus faecalis plasmid pCF10. J. Bacteriol. 173:76657672.
163. Pontius, L. T.,, and D. B. Clewell. 1991. A phase variation event that activates conjugation functions encoded by the Enterococcus faecalis plasmid pAD1. Plasmid 26:172185.
164. Pontius, L. T.,, and D. B. Clewell. 1992. Regulation of the pAD1-encoded pheromone response in Enterococcus faecalis: nucleotide sequence analysis of traA. J. Bacteriol. 174:18211827.
165. Pontius, L. T.,, and D. B. Clewell. 1992. Conjugative transfer of Enterococcus faecalis plasmid pADl: nucleotide sequence and transcriptional fusion analysis of a region involved in positive regulation, J. Bactenol. 174:31523160.
166. Poyart-Salmeron, C.,, P. Trieu-Cuot,, C. Carlier,, and P. Courvalin. 1989. Molecular characterization of two proteins involved in the excision of the conjugative transposon Tnl545: homologies with other site-specific recombinases. EMBO J. 8:24252433.
167. Poyart-Salmeron, C.,, P. Trieu-Cuot,, C. Carlier,, and P. Courvalin. 1990. The integration-excision system of the conjugative transposon Tn1545 is structurally and functionally related to those of lambdoid phages. Mol. Microbiol. 4:15131521.
168. Prowedi, R.,, R. Manganelli,, and G. Pozzi. 1996. Characterization of conjugative transposon Tn5251 of Streptococcus pneumoniae. FEMS Microbiol. Lett. 135: 231236.
169. Rakita, R. M.,, N. N. Vanek,, K. Jacques-Palaz,, M. Mee,, M. M. Mariscalco,, G. M. Dunny,, M. Snuggs,, W. B. Van Winkle,, and S. I. Simon. 1999. Enterococcus faecalis bearing aggregation substance is resistant to killing by human neutrophils despite phagocytosis and neutrophil activation. Infect. Immun. 67:60676075.
170. Rice, L. B. 1998. Tn916 family conjugative transposons and dissemination of antimicrobial resistance determinants. Antimicrob. Agents Chemother. 42:18711877.
171. Rice, L. B.,, and L. L. Carias. 1998. Transfer of Tn5385, a composite, multire-sistance chromosomal element from Enterococcus faecalis. J. Bacteriol. 180:714721.
172. Ruhfel, R. E.,, D. A. Manias,, and G. M. Dunny. 1993. Cloning and characterization of a region of the Enterococcus faecalis conjugative plasmid, pCF10, encoding a sex pheromone-binding function, J. Bacteriol. 175:52535259.
173. Salvers, A. A.,, N. B. Shoemaker,, A. M. Stevens,, and L. Y. Li. 1995. Conjugative transposons: an unusual and diverse set of integrated gene transfer elements. Microbiol. Rev. 59:579590.
174. Sannomiya, P.,, R. A. Craig,, D. B. Clewell,, A. Suzuki,, M. Fujino,, G. O. Till,, and W. A. Marasco. 1990. Characterization of a class of nonformylated Enterococcus faecalis-derived neutrophil chemotactic peptides: the sex pheromones. Proc. Natl. Acad. Set. USA 87:6670.
175. Schlievert, P. M.,, P. J. Gahr,, A. P. Assimacopoulos,, M. M. Dinges,, J. A. Stoehr,, J. W. Harmala,, H. Hirt,, and G. M. Dunny. 1998. Aggregation and binding substances enhance pathogenicity in rabbit models of Enterococcus faecalis endocarditis. Infect. Immun. 66:218223.
176. Schwarz, F. V.,, V. Perreten,, and M. Teuber. 2001. Sequence of the 50-kb conjugative multiresistance plasmid pRE25 from Enterococcus faecalis RE25. Plasmid 46:170187.
177. Scott, J. R.,, and G. Churchward. 1995. Conjugative transposition. Annu. Rev. Microbiol. 49:367397.
178. Scott, J. R.,, F. Bringel,, D. Marra,, G. Van Alstine,, and C. K. Rudy. 1994. Conjugative transposition of Tn926: preferred targets and evidence for conjugative transfer of a single strand and for a double-stranded circular intermediate. Mol. Microbiol. 11:10991108.
179. Scott, J. R.,, A. Kirchman,, and M. G. Caparon. 1988. An intermediate in transposition of the conjugative transposon Tn916. Proc. Natl. Acad. Sci. USA 85: 48094813.
180. Senghas, E.,, J. M. Jones,, M. Yamamoto,, C. Gawron-Burke,, and D. B. Clewell. 1988. Genetic organization of the bacterial conjugative transposon Tn916. J. Bacteriol. 170:245249.
181. Showsh, S. A.,, and R. E. Andrews, Jr. 1992. Tetracycline enhances Tn916-mediated conjugal transfer. Plasmid 28:213224.
182. Showsh, S. A.,, and R. E. Andrews, Jr. 1996. Functional comparison of conju-gative transposons Tn916 and Tn925. Plasmid 35:164173.
183. Showsh, S. A.,, and R. E. Andrews, Jr. 1999. Analysis of the requirement for a pUBHO mob region during Tn916-dependent mobilization. Plasmid 41:179186.
184. Showsh, S. A.,, E. H. De Boever,, and D. B. Clewell. 2001. Vancomycin resistance plasmid in Enterococcus faecalis that encodes sensitivity to a sex phero-mone also produced by Staphylococcus aureus. Antimicrob. Agents Chemother. 45: 21772178.
185. Su, Y. A.,, and D. B. Clewell. 1993. Characterization of the left four kilobases of conjugative transposon Tn926. Determinants involved in excision. Plasmid 30:234250.
186. Su, Y. A.,, P. He,, and D. B. Clewell. 1992. Characterization of the tetQA) determinant of Tn916: evidence for regulation by transcription attenuation. Antimicrob. Agents Chemother. 36:769778.
187. Sussmuth, S. D.,, A. Muscholl-Silberhorn,, R. Wirth,, M. Susa,, R. Marre,, and E. Rozdzinski. 2000. Aggregation substance promotes adherence, phagocytosis, and intracellular survival of Enterococcus faecalis within human macrophages and suppresses respiratory burst. Infect. Immun. 68:49004906.
188. Suzuki, A.,, M. Mori,, Y. Sakagami,, A. Isogai,, M. Fujino,, C. Kitada,, R. A. Craig,, and D. B. Clewell. 1984. Isolation and structure of bacterial sex pheromone, cPD1. Science 226:849850.
189. Swartley, J. S., C. F. McAllister, R. A. Hajjeh, D. W. Heinrich, and D. S. Stephens. 1993. Deletions of Tn926-like transposons are implicated in tetM-mediated resistance in pathogenic Neisseria. Mol. Microbiol. 10:299310.
190. Tanimoto, K.,, F. Y. An,, and D. B. Clewell. 1993. Characterization of the traC determinant of the Enterococcus faecalis hemolysin/bacteriocin plasmid pAD1. Binding of sex pheromone. J. Bacteriol. 175:52605264.
191. Tanimoto, K.,, and D. B. Clewell. 1993. Regulation of the pAD1-encoded sex pheromone response in Enterococcus faecalis-. expression of the positive regulator TraE1. J. Bacteriol. 175:10081018.
192. Tanimoto, K.,, H. Tomita,, and Y. Ike. 1996. The traA gene of the Enterococcus faecalis conjugative plasmid pPDl encodes a negative regulator for the pheromone response. Plasmid 36:5561.
193. Tomich, P. K.,, F. Y. An,, S. P. Damle,, and D. B. Clewell. 1979. Plasmid related transmissibility and multiple drug resistance in Streptococcus faecalis subspecies zymogenes strain DS16. Antimicrob. Agents Chemother. 15:828830.
194. Tomita, H..Personal communication.
195. Tomita, H.,, and D. B. Clewell. 2000. A pAD1-encoded small RNA molecule, mD, negatively regulates Enterococcus faecalis pheromone response by enhancing transcription termination. J. Bacteriol. 182:10621073.
196. Tomita, H.,, S. Fujimoto,, K. Tanimoto,, and Y. Ike. 1997. Cloning and genetic and sequence analyses of the bacteriocin 21 determinant encoded on the Enterococcus faecalis pheromone-responsive conjugative plasmid pPD1. J. Bacteriol. 179:78437855.
197. Tomita, H.,, S. Fujimoto,, K. Tanimoto,, and Y. Ike. 1996. Cloning and genetic organization of the bacteriocin 31 determinant encoded on the Enterococcus faecalis pheromone-responsive conjugative plasmid pYI17. J. Bacteriol. 178:35853593.
198. Torres, O. R.,, R. Z. Korman,, S. A. Zahler,, and G. M. Dunny. 1991. The conjugative transposon Tn925: enhancement of conjugal transfer by tetracycline in Enterococcus faecalis and mobilization of chromosomal genes in Bacillus subtilis and E. faecalis. Mol. Gen. Genet. 225:395400.
199. Trotter, K. M.,, and G. M. Dunny. 1990. Mutants of Enterococcus faecalis deficient as recipients in mating with donors carrying pheromone-inducible plasmids. Plasmid 24:5767.
200. Wanner, G.,, H. Formanek,, D. Galli,, and R. Wirth. 1989. Localization of aggregation substances of Enterococcus faecalis after induction by sex pheromones. An ultrastructural comparison using iirtmunolabelling, transmission and high resolution scanning electron microscopic techniques. Arch. Microbiol. 151:491497.
201. Waters, C. M.,, and G. M. Dunny. 2001. Analysis of functional domains of the Enterococcus faecalis pheromone-induced surface protein aggregation substance. J. Bacteriol. 183:56595667.
202. Weaver, K. E.,, and D. B. Clewell. 1988. Regulation of the pADl sex pheromone response in Enterococcus faecalis: construction and characterization of lacZ tran-scriptional fusions in a key control region of the plasmid. J. Bacteriol. 170:43434352.
203. Weaver, K. E.,, and D. B. Clewell. 1989. Construction of Enterococcus faecalis pADl miniplasmids: identification of a minimal pheromone response regulatory region and evaluation of a novel pheromone-dependent growth inhibition. Plasmid 22:106119.
204. Weaver, K. E.,, and D. B. Clewell. 1990. Regulation of the pADl sex pheromone response in Enterococcus faecalis: effects of host strain and traA, traB, and C region mutants on expression of an E region pheromone-inducible lacZ fusion. J. Bacteriol. 172:26332641.
205. Weaver, K. E.,, and D. B. Clewell. 1991. Control of Enterococcus faecalis sex pheromone cAD1 elaboration: effects of culture aeration and pAD1 plasmid-encoded determinants. Plasmid 25:177189.
206. Weaver, K. E.,, D. B. Clewell,, and E Y. An. 1993. Identification, characterization, and nucleotide sequence of a region of Enterococcus faecalis pheromone-responsive plasmid pAD1 capable of autonomous replication, J. Bacteriol. 175: 19001909.
207. Weidlich, G.,, R. Wirth,, and D. Galli. 1992. Sex pheromone plasmid pADl-encoded surface exclusion protein of Enterococcus faecalis. Mol. Gen. Genet. 233: 161168.
208. Wirth, R. 1994. The sex pheromone system of Enterococcus faecalis. More than just a plasmid-collection mechanism? Eur. J. Biochem. 222:235246.
209. Wirth, R. 2000. Sex pheromones and gene transfer in Enterococcus faecalis. Res. Microbiol. 151:493496.
210. Wirth, R.,, A. Friesenegger,, and T. Horaud. 1992. Identification of new sex pheromone plasmids in Enterococcus faecalis. Mol. Gen. Genet. 233:157160.
211. Wirth, R.,, and H. Marcinek,. 1995. In vivo gene transfer by Enterococcus faecalis, p. 51-54. In J. J. Ferretti,, M. S. Gilmore,, T. R. Klaenhammer,, and F. Brown (eds.), Genetics of Streptococci, Enterococci and Lactococci. Developmental and Biological Standards, vol. 85. Karger, Basel, Switzerland.
212. Wirth, R.,, A. Muscholl,, and G. Wanner. 1996. The role of pheromones in bacterial interaction. Trends Microbiol. 4:96103.
213. Wu, H. C., 1996. Biosynthesis of lipoproteins, p. 10051014. In F. C. Neidhardt,, R. Curtiss III,, J. L. Ingraham,, E. C. C. Lin,, K. B. Low,, B. Magasanik,, W. S. Reznikoff,, M. Riley,, M. Schaechter,, and H. E. Umbarger (éd.), Escherichia coli and Salmonella, 2nd ed. ASM Press, Washington, D.C.
214. Wu, K.,, F. Y. An,, and D. B. Clewell. 1999. Enterococcus faecalis pheromone-responding plasmid pADl gives rise to an aggregation (clumping) response when cells are exposed to subinhibitory concentrations of chloramphenicol, erythromycin, or tetracycline. Plasmid 41:8288.
215. Yagi, Y.,, R. E. Kessler,, J. H. Shaw,, D. E. Lopatin,, F. Y. An,, and D. B. Clewell. 1983. Plasmid content of Streptococcus faecalis strain 39-5 and identification of a pheromone (cPDl)-induced surface antigen, J. Gen. Microbiol. 129:12071215.
216. Yarnell, W. S.,, and J. W. Roberts. 1999. Mechanism of intrinsic transcription termination and antitermination. Science 284:611615.

Tables

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Table 1

Plasmids that encode a pheromone response

Citation: Clewell D, Dunny G. 2002. Conjugation and Genetic Exchange in Enterococci, p 265-300. In Gilmore M, Clewell D, Courvalin P, Dunny G, Murray B, Rice L (ed), The Enterococci. ASM Press, Washington, DC. doi: 10.1128/9781555817923.ch7
Generic image for table
Table 2

Pheromone and inhibitor precursors

Citation: Clewell D, Dunny G. 2002. Conjugation and Genetic Exchange in Enterococci, p 265-300. In Gilmore M, Clewell D, Courvalin P, Dunny G, Murray B, Rice L (ed), The Enterococci. ASM Press, Washington, DC. doi: 10.1128/9781555817923.ch7

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