Search results for "DNA FINGERPRINT"
showing 10 items of 95 documents
Diversity of rhizobia nodulating wild shrubs of Sicily and some neighbouring islands
2008
Abstract Legume shrubs have great potential for rehabilitation of semi-arid degraded soils in Mediterranean ecosystems as they establish mutualistic symbiosis with Nfxing rhizobia. Eighty-eight symbiotic rhizobia were isolated from seven wild legume shrubs native of Sicily (Southern Italy) and grouped in operational taxonomic units (OTU) by analysis of the ribosomal internal transcribed spacer (ITS) polymorphism. Partial sequencing of 16S rRNA gene of representative isolates of each OTU revealed that most Genisteae symbionts are related to Bradyrhizobium canariense, B. japonicum and B. elkanii. Teline monspessulana was the only Genistea nodulated by Mesorhizobium strains, and Anagyris foeti…
Genotypic characterization of Bradyrhizobium strains nodulating small Senegalese legumes by 16S-23S rRNA intergenic gene spacers and amplified fragme…
2000
ABSTRACT We examined the genotypic diversity of 64 Bradyrhizobium strains isolated from nodules from 27 native leguminous plant species in Senegal (West Africa) belonging to the genera Abrus , Alysicarpus , Bryaspis , Chamaecrista , Cassia , Crotalaria , Desmodium , Eriosema , Indigofera , Moghania , Rhynchosia , Sesbania , Tephrosia , and Zornia , which play an ecological role and have agronomic potential in arid regions. The strains were characterized by intergenic spacer (between 16S and 23S rRNA genes) PCR and restriction fragment length polymorphism (IGS PCR-RFLP) and amplified fragment length polymorphism (AFLP) fingerprinting analyses. Fifty-three reference strains of the different B…
Effect of natamycin on the enumeration, genetic structure and composition of bacterial community isolated from soils and soybean rhizosphere
2004
Natamycin is commonly used to control fungal growth on agar media used for bacterial enumeration or strain isolation. However, there is no conclusive report on the possible effect of this antibiotic on bacterial growth or on the diversity of the recovered soil bacteria. Therefore, the possible effects of natamycin on the numbers of bacteria isolated at 12 degrees C from three different soils and soybean rhizosphere soil were investigated using natamycin concentrations ranging from 0 to 200 mg l(-1). Our results demonstrate that natamycin concentrations, which inhibit the growth of fungi on the media, have a small but significant inhibitory effect on the number of bacterial colony forming un…
DNA Amplification Fingerprinting for Subtyping Neisseria gonorrhoeae Strains
1995
Background and Objectives DNA amplification fingerprinting is used in most epidemiologic studies as a substitute for conventional typing methods. DNA amplification fingerprinting and conventional typing methods were compared in this epidemiologic study of Neisseria gonorrhoeae. Goal of This Study To differentiate 70 Neisseria gonorrhoeae isolates from untreated patients with urogenital gonococcal infection. Study Design Gonococcal strains were characterized by auxo-typing, serotyping, plasmid profile, antibiotic sensitivity, and DNA amplification fingerprinting. The method of unweighted pair-group average linkage was used for cluster analysis. Discriminatory power was calculated applying Si…
Identification of bacterial groups preferentially associated with mycorrhizal roots of Medicago truncatula
2007
ABSTRACT The genetic structures of bacterial communities associated with Medicago truncatula Gaertn. cv. Jemalong line J5 (Myc + Nod + ) and its symbiosis-defective mutants TRV48 (Myc + Nod − ) and TRV25 (Myc − Nod − ) were compared. Plants were cultivated in a fertile soil (Châteaurenard, France) and in soil from the Mediterranean basin showing a low fertility (Mas d'Imbert, France). Plant growth, root architecture, and the efficiency of root symbiosis of the three plant genotypes were characterized in the two soils. Structures of the bacterial communities were assessed by automated-ribosomal intergenic spacer analysis (A-RISA) fingerprinting from DNA extracted from the rhizosphere soil an…
Lactobacillus oeni sp. nov., from wine.
2009
Ten Lactobacillus strains, previously isolated from different Bobal grape wines from the Utiel-Requena Origin Denomination of Spain, were characterized phylogenetically, genotypically and phenotypically. The 16S rRNA genes were sequenced and phylogenetic analysis showed that they form a tight phylogenetic clade that is closely related to reference strains Lactobacillus satsumensis NRIC 0604T, ‘Lactobacillus uvarum’ 8 and Lactobacillus mali DSM 20444T. DNA–DNA hybridization results confirmed the separation of the strains from other Lactobacillus species. Genotypically, the strains could be differentiated from their closest neighbours by 16S amplified rDNA restriction analysis and random ampl…
Characterization of Bacterial and Fungal Soil Communities by Automated Ribosomal Intergenic Spacer Analysis Fingerprints: Biological and Methodologic…
2001
ABSTRACT Automated rRNA intergenic spacer analysis (ARISA) was used to characterise bacterial (B-ARISA) and fungal (F-ARISA) communities from different soil types. The 16S-23S intergenic spacer region from the bacterial rRNA operon was amplified from total soil community DNA for B-ARISA. Similarly, the two internal transcribed spacers and the 5.8S rRNA gene (ITS1-5.8S-ITS2) from the fungal rRNA operon were amplified from total soil community DNA for F-ARISA. Universal fluorescence-labeled primers were used for the PCRs, and fragments of between 200 and 1,200 bp were resolved on denaturing polyacrylamide gels by use of an automated sequencer with laser detection. Methodological (DNA extracti…
Cumulative Effects of Short-Term Polymetal Contamination on Soil Bacterial Community Structure
2006
ABSTRACT In this study we evaluated the short-term effects of copper, cadmium, and mercury, added singly or in combination at different doses, on soil bacterial community structure using the bacterial automated ribosomal intergenic spacer analysis (B-ARISA) fingerprinting technique. Principal-component analysis of B-ARISA profiles allowed us to deduce the following order of impact: (Cu + Cd + Hg) >> Hg ≥ Cd > Cu. These results demonstrated that there was a cumulative effect of metal toxicity. Furthermore, the trend of modifications was consistent with the “hump-backed” relationships between biological diversity and disturbance described by Giller et al. (K. E. Giller, E. Witler, an…
Polyphasic taxonomic characterization of Lactobacillus rossiae isolates from Belgian and Italian sourdoughs reveals intraspecific heterogeneity.
2009
Abstract (GTG) 5 -PCR fingerprinting and pheS sequence analysis of 18 Lactobacillus rossiae isolates, mainly originating from Belgian and Italian artisan sourdoughs, revealed intraspecies grouping as evidenced by the delineation of three and two subgroups, respectively. On the other hand, 16S rRNA and rpoA gene sequence analysis and DNA–DNA hybridizations supported the accommodation of all isolates in a single species. No correlation between genetic and phenotypic heterogeneity was observed. Collectively, these data do not warrant taxonomic division of L. rossiae . On the other hand, the considerable differences in intraspecies sequence variation of L. rossiae isolates displayed by the pheS…
Epidemiology ofSalmonella typhimurium: ribosomal DNA analysis of strains from human and animal sources
1993
SUMMARYSalmonella typhimuriumis the most frequently identified serovar ofSalmonellain Italy. This serovar is characterized by the widespread dissemination among human and non-human sources of phenotypically and genetically well-differentiated clones.In this study 457 strains ofS. typhimuriumisolated in Italy in the years 1982–91 from human and animal sources were submitted to characterization by the rDNA fingerprinting technique. Application of this typing method, after digestion of chromosomal DNA withHincII endonuclease, confirmed the greatest genetic differentiation of clones ofS. typhimurium, allowing reliable identification of 45 rDNA patterns linked into 9 major clusters. rDNA pattern…