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ANNUAL CONFERENCE :: Abstract Library
Abstract Library
2003 Conference Abstract
| Type of Submission |
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Submission Type: |
Poster Presentation |
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Subject Category: |
Applied Microbiology |
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| Session Information |
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Presentation Date: |
May 26, 2003 |
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Abstract ID: |
A20 |
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Session: |
Poster 1 |
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Time: |
14:00 |
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| Presenting Author |
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| Other Authors |
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D.R. ROY, Agriculture and Agri-Food Canada
S.R. SIROIS, Agriculture and Agri-Food Canada
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| Title |
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Use of tnp gene, an IS30-family insertion sequence isolated from Lactobacillus rhamnosus for strain differentiation in Lactobacillus casei -complex. |
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| Abstract Text |
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Lactic acid bacteria have been used for millennia for the production of fermented foods. Among them, Lactobacillus casei -complex comprising Lactobacillus casei , Lactobacillus zeae and Lactobacillus rhamnosus is of interest because strains from this complex can be used for technological and probiotic applications. Molecular methods based on sequence of the 16S rRNA gene (rDNA) such as specific probes or Amplified Ribosomal DNA Restriction Analysis (ARDRA) have been used for identification of these species. However, this technology carries the inherent problem of heterogeneity between copies of the 16S rDNA in many species. The aim of this study was to use an insertion element for strain differentiation among the L. casei -complex as an alternative to 16S rDNA sequences in bacterial identification. An insertion sequence has been previously identified in the genome of L. rhamnosus RW-9595M as a segment of 1017 nucleotides flanked upstream and downstream of inverted repeats of 19 nucleotides. The open reading frame of this element encodes a 339 amino acid protein that displays similarities with transposases encoded by bacterial insertion sequences belonging to the IS30 family. PCR screening from 66 strains belonging to Lactobacillus spp., Bifidobacterium spp. Streptococcus thermophilus and Escherichia coli confirms that tnp or highly similar sequence is found only in Lactobacillus spp. With a PCR base approach, this element was detected in 43 strains of the Lactobacillus casei - complex. Sequence analysis of 14 PCR products of 1017 nucleotides from strains of L. casei , L. zeae and L. rhamnosus revealed 100% similariy between seven strains of L. rhamnosus (ATCC 9595, ATCC 12116, ATCC 21052, ATCC 27773, R, RW-6541M and CLI2552) and L. rhamnosus RW-9595M. In addition, 100% similarity was also observed for L. zeae ATCC 393 with RW-9595M. However, sequence from L. zeae ATCC 15820 differed from L. rhamnosus . Strains of L. casei can be differentiated by sequencing PCR products. Results suggest that the PCR approach based on tnp gene and subsequent sequence analysis can be used for strain differentiation among Lactobacillus spp. |
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