Search results for "rase"
showing 10 items of 4343 documents
Comparison of Four Commercial DNA Extraction Kits for PCR Detection of Listeria monocytogenes, Salmonella, Escherichia coli O157:H7, and Staphylococc…
2008
Four commercial DNA extraction methods, PrepMan Ultra (Applied Biosystems), InstaGene Matrix (BioRad), DNeasy Tissue kit (Qiagen), and UltraClean (MoBio), were tested for PCR detection of Listeria monocytogenes, Escherichia coli O157: H7, Salmonella, and Staphylococcus aureus in fresh, minimally processed vegetables. For comparative purposes, sensitivity assays with specific PCRs were carried out after DNA extraction with the four methods in green pepper, broccoli, and onion artificially inoculated with the four pathogens separately. As confirmed by statistical analysis, the DNeasy Tissue kit rendered the highest sensitivity values in the three matrices assayed for Salmonella, L. monocytoge…
In vitro and in vivo sulfate reduction in the gut contents of the termite Mastotermes darwiniensis and the rose-chafer Pachnoda marginata.
2005
Sulfate-reducing bacteria (SRB) from termites have been assigned to the genus Desulfovibrio. Desulfovibrio intestinalis lives in the gut of the Australian termite Mastotermes darwiniensis. For the first time we were able to enrich and identify a sulfate-reducing bacterium from the gut of the rose-chafer Pachnoda marginata, which showed the highest 16S rDNA sequence identity (93%) to Desulfovibrio intestinalis and Desulfovibrio strain STL1. Compared to Mastotermes darwiniensis (1x10(7) cells of SRB per ml gut contents), sulfate-reducing bacteria occurred in higher numbers in the gut contents of Pachnoda marginata reaching cell titers of up to 2x10(8) cells per ml gut contents. In vitro sulfa…
Transcription analysis of the genes tcdA-E of the pathogenicity locus of Clostridium difficile.
1997
To analyse the transcription pattern of the five tcdA-E genes of the pathogenicity locus (PaLoc) of Clostridium difficile a protocol was established to purify RNA from strain VPI10463. Transcription analysis of the five tcdA-E genes showed that they were all transcribed. In the early exponential phase, a high level of tcdC and low levels of tcdA,B,D,E transcripts were detectable; this was inverted in the stationary phase, suggesting that TcdC might have a negative influence on transcription of the other genes. Three transcription initiation sites, one for tcdA and two for tcdB were determined by primer extension analysis. Readthrough transcripts from outside the locus were not obtainable, s…
Clostridium difficile toxin A carries a C-terminal repetitive structure homologous to the carbohydrate binding region of streptococcal glycosyltransf…
1990
A detailed analysis of the 8130-bp open reading frame (ORF) of gene toxA and of an upstream ORF designated utxA, indicates the presence of a transcription terminator stem-loop for toxA, promoter sequences, and Shine-Dalgarno boxes for toxA and utxA. No transcription terminator between toxA and utxA is suggested by the sequence. ToxA contains two domains, one-third (C-terminal) with a repetitive structure and the residual two-thirds with no repetitions. The 2499-bp sequence encoding the repetitive structure is composed of nine groups of different short repetitive oligodeoxyribonucleotides (SRONs). A combination of these SRONs codes for five groups of combined repetitive oligopeptides (CROPs)…
T-DNA insertion alters the terpenoid content composition and bioactivity of transgenic Artemisia annua.
2014
In this study, the interference of T-DNA insertion upon Agrobacterium-mediated transformation on the biochemical expression of the host genome is discussed. Plant extracts of transgenic Artemisia annua L. with or without an overexpressed farnesyl pyrophosphate synthase gene have been investigated for their bioactivity and metabolic profile in comparison with wild type A. annua. The highest antimicrobial activity against Staphylococcus aureus, Bacillus subtilis and Candida albicans was observed in the T253 transgenic lines. Moreover, the crude extract from T253 showed higher antimalarial activity against the Plasmodium faciparum K1 strain than those of the others. The terpenoid constituents…
Simultaneous detection of Carnobacterium and Leuconostoc in meat products by multiplex PCR.
2004
M.C. MACIAN, E. CHENOLL AND R. AZNAR. 2004. Aims: To develop a multiplex PCR approach for simultaneous detection of Leuconostoc and Carnobacterium and its validation in meat products. Methods and Results: Two multiplex PCR assays were developed using newly designed 16S rDNA-directed primers adapted to the current taxonomic situation of genera Leuconostoc and Carnobacterium that allow: (i) simultaneous detection of both genera, and members of the nonmotile species of genus Carnobacterium and (ii) identification in a single assay of the nonmotile species C. divergens, C. maltaromicum and C. gallinarum. Sensitivity values of 10 3 and 10 4 CFU g )1 were determined for multiplex PCR detection of…
Development and validation of two PCR tests for the detection of and differentiation between Anaplasma ovis and Anaplasma marginale
2012
Anaplasma ovis and Anaplasma marginale are tick-transmitted bacteria that cause anaplasmosis in domestic and wild animals. Recent results show that some domestic and wild animals and ticks are susceptible to both A. ovis and A. marginale, thus supporting the need to differentiate between these species in hosts and ticks diagnosed with Anaplasma infection. However, although anaplasmosis is one of the most common diseases of grazing animals worldwide, rapid and effective tests are not available for the detection of and discrimination between these 2 Anaplasma species. The objective of this research was to develop an easy and reliable method to identify and discriminate between the closely rel…
16S-ARDRA, a tool for identification of lactic acid bacteria isolated from grape must and wine.
2003
Lactic acid bacteria (LAB) are found in a great variety of habitats, including grape must and wines. There is a close relationship between the species of LAB which develop during fermentation and the eventual quality of the wine. For these reasons analytical techniques allowing fast and reliable identification of wine LAB are needed. In this work a simple and accurate protocol for identifying species of LAB isolated from grape must and wine is presented. This protocol is based on the amplification, directly from colony, of 16S rDNA and later digestion with one of the following restriction enzymes BfaI, MseI and AluI. A sequential use of the three enzymes is proposed to simplify LAB wine ide…
Characterization and transcriptional analysis of Pseudomonas fluorescens denitrifying clusters containing the nar, nir, nor and nos genes
2001
In this study, we report the cloning and characterization of denitrifying gene clusters of Pseudomonas fluorescens C7R12 containing the narXLDKGHJI, nirPOQSM, norCB and nosRZDFYL genes. While consensus sequences for Fnr-like protein binding sites were identified in the promoter regions of the nar, nir, nor and nos genes, consensus sequences corresponding to the NarL binding sites were identified only upstream the nar genes. Monitoring by mRNA analysis the expression of the narG, nirS, norB and nosZ structural genes suggests a sequential induction of the denitrification system in P. fluorescens.
Identification of Critical Genes for Growth in Olive Brine by Transposon Mutagenesis of Lactobacillus pentosus C11
2013
ABSTRACT Olive brine represents a stressful environment due to the high NaCl concentration, presence of phenolic compounds known as antimicrobials, and low availability of nutrients. Thus, only a few strains of lactic acid bacteria (LAB) are adapted to grow in and ferment table olives. To identify the mechanisms by which these few strains are able to grow in olive brine, Lactobacillus pentosus C11, a particularly resistant strain isolated from naturally fermented table olives, was mutagenized by random transposition using the P junc -TpaseIS 1223 system (H. Licandro-Seraut, S. Brinster, M. van de Guchte, H. Scornec, E. Maguin, P. Sansonetti, J. F. Cavin, and P. Serror, Appl. Environ. Microb…