Previous Article | Next Article ![]()
Applied and Environmental Microbiology, November 2006, p. 6955-6964, Vol. 72, No. 11
0099-2240/06/$08.00+0 doi:10.1128/AEM.00934-06
Copyright © 2006, American Society for Microbiology. All Rights Reserved.
Department of Bacteriology and Bacterial Infection Control,1 Department of Ophthalmology,2 Laboratory of Bacterial Drug Resistance, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511, Japan3
Received 20 April 2006/ Accepted 9 August 2006
A total of 636 vancomycin-resistant Enterococcus faecium (VRE) isolates obtained between 1994 and 1999 from the Medical School Hospital of the University of Michigan were tested for bacteriocin production. Of the 277 (44%) bacteriocinogenic strains, 21 were active against E. faecalis, E. faecium, E. hirae, E. durans, and Listeria monocytogenes. Of those 21 strains, a representative bacteriocin of strain VRE82, designated bacteriocin 43, was found to be encoded on mobilizable plasmid pDT1 (6.2 kbp). Nine open reading frames (ORFs), ORF1 to ORF9, were presented on pDT1 and were oriented in the same direction. The bacteriocin 43 locus (bac43) consists of the bacteriocin gene bacA (ORF1) and the immunity gene bacB (ORF2). The deduced bacA product is 74 amino acids in length with a putative signal peptide of 30 amino acids at the N terminus. The bacB gene encodes a deduced 95-amino-acid protein without a signal sequence. The predicted mature BacA protein (44 amino acids) showed sequence homology with the membrane-active class IIa bacteriocins of lactic acid bacteria and showed 86% homology with bacteriocin 31 from E. faecalis YI717 and 98% homology with bacteriocin RC714. Southern analysis with a bac43 probe of each plasmid DNA from the 21 strains showed hybridization to a specific fragment corresponding to the 6.2-kbp EcoRI fragment, suggesting that the strains harbored the pDT1-like plasmid (6.2 kb) which encoded the bacteriocin 43-type bacteriocin. The bac43 determinant was not identified among non-VRE clinical isolates.
Published ahead of print on 21 August 2006.
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»