TY - JOUR
T1 - A novel conjugative plasmid from Enterococcus faecalis E99 enhances resistance to ultraviolet radiation
AU - Coburn, Phillip S.
AU - Baghdayan, Arto S.
AU - Craig, Nikki
AU - Burroughs, Adam
AU - Tendolkar, Preeti
AU - Miller, Kris
AU - Najar, Fares Z.
AU - Roe, Bruce A.
AU - Shankar, Nathan
N1 - Funding Information:
This work was supported, in part, by the Oklahoma Center for the Advancement of Science and Technology (OCAST) through Health Research Program Grant HR06-104, and by NIH R01 AI059673 to N.S. We thank Helmut Hirt for performing the cCF10 clumping assay, Keith Weaver for analysis of the RepA-encoding region of pBEE99, and Catherine King for performing the spot ultraviolet sensitivity test. We also thank Tamara Hunt for technical support and Mark Huycke for helpful discussions.
PY - 2010/7
Y1 - 2010/7
N2 - Enterococcus faecalis has emerged as a prominent healthcare-associated pathogen frequently encountered in bacteremia, endocarditis, urinary tract infection, and as a leading cause of antibiotic-resistant infections. We recently demonstrated a capacity for high-level biofilm formation by a clinical E. faecalis isolate, E99. This high biofilm-forming phenotype was attributable to a novel locus, designated bee, specifying a pilus at the bacterial cell surface and localized to a large ∼80. kb conjugative plasmid. To better understand the origin of the bee locus, as well as to potentially identify additional factors important to the biology and pathogenesis of strain E99, we sequenced the entire plasmid. The nucleotide sequence of the plasmid, designated pBEE99, revealed large regions of identity to the previously characterized conjugative plasmid pCF10. In addition to the bee locus, pBEE99 possesses an open reading frame potentially encoding aggregation substance, as well as open reading frames putatively encoding polypeptides with 60% to 99% identity at the amino acid level to proteins involved in regulation of the pheromone response and conjugal transfer of pCF10. However, strain E99 did not respond to the cCF10 pheromone in clumping assays. While pBEE99 was found to be devoid of any readily recognizable antibiotic resistance determinants, it carries two non-identical impB/. mucB/. samB-type genes, as well as genes potentially encoding a two-component bacteriocin similar to that encoded on pYI14. Although no bacteriocin activity was detected from an OG1RF transconjugant carrying pBEE99 against strain FA2-2, it was approximately an order of magnitude more resistant to ultraviolet radiation. Moreover, curing strain E99 of this plasmid significantly reduced its ability to survive UV exposure. Therefore, pBEE99 represents a novel conjugative plasmid that confers biofilm-forming and enhanced UV resistance traits that might potentially impact the virulence and/or fitness of E. faecalis.
AB - Enterococcus faecalis has emerged as a prominent healthcare-associated pathogen frequently encountered in bacteremia, endocarditis, urinary tract infection, and as a leading cause of antibiotic-resistant infections. We recently demonstrated a capacity for high-level biofilm formation by a clinical E. faecalis isolate, E99. This high biofilm-forming phenotype was attributable to a novel locus, designated bee, specifying a pilus at the bacterial cell surface and localized to a large ∼80. kb conjugative plasmid. To better understand the origin of the bee locus, as well as to potentially identify additional factors important to the biology and pathogenesis of strain E99, we sequenced the entire plasmid. The nucleotide sequence of the plasmid, designated pBEE99, revealed large regions of identity to the previously characterized conjugative plasmid pCF10. In addition to the bee locus, pBEE99 possesses an open reading frame potentially encoding aggregation substance, as well as open reading frames putatively encoding polypeptides with 60% to 99% identity at the amino acid level to proteins involved in regulation of the pheromone response and conjugal transfer of pCF10. However, strain E99 did not respond to the cCF10 pheromone in clumping assays. While pBEE99 was found to be devoid of any readily recognizable antibiotic resistance determinants, it carries two non-identical impB/. mucB/. samB-type genes, as well as genes potentially encoding a two-component bacteriocin similar to that encoded on pYI14. Although no bacteriocin activity was detected from an OG1RF transconjugant carrying pBEE99 against strain FA2-2, it was approximately an order of magnitude more resistant to ultraviolet radiation. Moreover, curing strain E99 of this plasmid significantly reduced its ability to survive UV exposure. Therefore, pBEE99 represents a novel conjugative plasmid that confers biofilm-forming and enhanced UV resistance traits that might potentially impact the virulence and/or fitness of E. faecalis.
KW - Bacteriocin
KW - Bee locus
KW - Conjugation
KW - Enterococcus faecalis
KW - PBEE99
KW - Ultraviolet radiation resistance
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U2 - 10.1016/j.plasmid.2010.03.001
DO - 10.1016/j.plasmid.2010.03.001
M3 - Article
C2 - 20307569
AN - SCOPUS:77953537725
SN - 0147-619X
VL - 64
SP - 18
EP - 25
JO - Plasmid
JF - Plasmid
IS - 1
ER -