« Previous Abstract"MFalpha1, the gene encoding the alpha mating pheromone of Candida albicans"    Next Abstract"Date palm responses to a chronic, realistic ozone exposure in a FACE experiment" »

J Antimicrob Chemother

Title:		Co-transfer of vanA and aggregation substance genes from Enterococcus faecalis isolates in intra- and interspecies matings
Author(s):		Paoletti C; Foglia G; Princivalli MS; Magi G; Guaglianone E; Donelli G; Pruzzo C; Biavasco F; Facinelli B;
Address:		"Institute of Microbiology and Biomedical Sciences, Polytechnic University of Marche, 60100 Ancona, Italy"
Journal Title:		J Antimicrob Chemother
Year:		2007
Volume:		20070309
Issue:		5
Page Number:		1005 - 1009
DOI:		10.1093/jac/dkm057
ISSN/ISBN:		0305-7453 (Print) 0305-7453 (Linking)
Abstract:		"OBJECTIVES: The study was undertaken to investigate vancomycin-resistant (vanA) Enterococcus faecalis isolates carrying aggregation substance (AS) gene(s) for their ability to co-transfer vanA and AS genes. METHODS: Six vanA clumping-positive E. faecalis isolates (five human and one food sample) carrying one or more AS genes (prgB, asa1, asa373) were analysed for co-transfer of vanA and AS genes to E. faecalis JH2-2 and Enterococcus faecium 64/3. RESULTS: E. faecalis isolates harboured one or multiple plasmids carrying vanA, one or more AS gene(s) or both. vanA was transferred to JH2-2 (frequencies of 10(-3)-10(-6)) from all donors and to 64/3 (10(- 6)-10(- 8)) only from donors from humans. AS genes were detected in 51/60 (85%) of JH2-2 and in 20/50 (40%) of 64/3 vanA transconjugants (prgB, asa1, asa373 or prgB asa373), of which a total of 53.6% were clumping-positive. The plasmid content of JH2-2 transconjugants from the same donor was either identical to that of the donor or it was completely different, suggesting different mechanisms for co-transfer (location on the same pheromone plasmid, mobilization of vanA plasmids by the pheromone-inducible conjugation system, rearrangement of plasmid content during matings). After induction with pheromones, a marked increase in adhesion to Caco-2 cells was observed in four isolates and in some JH2-2 transconjugants, all clumping-positive. CONCLUSIONS: Findings suggest that co-transfer of vanA and AS genes may be a common feature of E. faecalis isolates. Since AS is recognized as a virulence factor, this feature might contribute to the emergence of strains with enhanced ability to cause infection and disease in humans"
Keywords:		"Bacterial Adhesion Bacterial Proteins/*genetics Caco-2 Cells Carbon-Oxygen Ligases/*genetics Conjugation, Genetic Enterococcus faecalis/*genetics/isolation & purification/physiology Enterococcus faecium/genetics Food Microbiology Humans Pheromones/genetic;"
Notes:		"MedlinePaoletti, Claudia Foglia, Gessica Princivalli, Maria Stella Magi, Gloria Guaglianone, Emilio Donelli, Gianfranco Pruzzo, Carla Biavasco, Francesca Facinelli, Bruna eng Research Support, Non-U.S. Gov't England 2007/03/14 J Antimicrob Chemother. 2007 May; 59(5):1005-9. doi: 10.1093/jac/dkm057. Epub 2007 Mar 9"