scholarly journals Genotypic Characterization of Bradyrhizobium Strains Nodulating Small Senegalese Legumes by 16S-23S rRNA Intergenic Gene Spacers and Amplified Fragment Length Polymorphism Fingerprint Analyses

2000 ◽  
Vol 66 (9) ◽  
pp. 3987-3997 ◽  
Author(s):  
Florence Doignon-Bourcier ◽  
Anne Willems ◽  
Renata Coopman ◽  
Gisele Laguerre ◽  
Monique Gillis ◽  
...  

ABSTRACT We examined the genotypic diversity of 64Bradyrhizobium 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 Bradyrhizobium species and described groups were included for comparison. The strains were diverse and formed 27 groups by AFLP and 16 groups by IGS PCR-RFLP. The sizes of the IGS PCR products from the Bradyrhizobium strains that were studied varied from 780 to 1,038 bp and were correlated with the IGS PCR-RFLP results. The grouping of strains was consistent by the three methods AFLP, IGS PCR-RFLP, and previously reported 16S amplified ribosomal DNA restriction analysis. For investigating the whole genome, AFLP was the most discriminative technique, thus being of particular interest for future taxonomic studies in Bradyrhizobium, for which DNA is difficult to obtain in quantity and quality to perform extensive DNA:DNA hybridizations.

1999 ◽  
Vol 181 (15) ◽  
pp. 4469-4475 ◽  
Author(s):  
Adam Meijer ◽  
Servaas A. Morré ◽  
Adriaan J. C. Van Den Brule ◽  
Paul H. M. Savelkoul ◽  
Jacobus M. Ossewaarde

ABSTRACT The genomic relatedness of 19 Chlamydia pneumoniaeisolates (17 from respiratory origin and 2 from atherosclerotic origin), 21 Chlamydia trachomatis isolates (all serovars from the human biovar, an isolate from the mouse biovar, and a porcine isolate), 6 Chlamydia psittaci isolates (5 avian isolates and 1 feline isolate), and 1 Chlamydia pecorum isolate was studied by analyzing genomic amplified fragment length polymorphism (AFLP) fingerprints. The AFLP procedure was adapted from a previously developed method for characterization of clinical C. trachomatis isolates. The fingerprints of all C. pneumoniae isolates were nearly identical, clustering together at a Dice similarity of 92.6% (± 1.6% standard deviation). The fingerprints of the C. trachomatis isolates of human, mouse, and swine origin were clearly distinct from each other. The fingerprints of the isolates from the human biovar could be divided into at least 12 different types when the presence or absence of specific bands was taken into account. The C. psittacifingerprints could be divided into a parakeet, a pigeon, and a feline type. The fingerprint of C. pecorum was clearly distinct from all others. Cluster analysis of selected isolates from all species revealed groups other than those based on sequence data from single genes (in particular, omp1 and rRNA genes) but was in agreement with available DNA-DNA hybridization data. In conclusion, cluster analysis of AFLP fingerprints of representatives of all species provided suggestions for a grouping of chlamydiae based on the analysis of the whole genome. Furthermore, genomic AFLP analysis showed that the genome of C. pneumoniae is highly conserved and that no differences exist between isolates of respiratory and atherosclerotic origins.


2000 ◽  
Vol 38 (9) ◽  
pp. 3379-3387 ◽  
Author(s):  
Bjørn-Arne Lindstedt ◽  
Even Heir ◽  
Traute Vardund ◽  
Kjetil K. Melby ◽  
Georg Kapperud

Amplified-fragment length polymorphism (AFLP) analysis with the endonucleases BglII and MfeI was used to genotype 91 Campylobacter jejuni subsp. jejunistrains from outbreaks and sporadic cases. AFLP-generated fragments were labeled with fluorescent dye and separated by capillary electrophoresis. The software packages GeneScan and GelCompar II were used to calculate AFLP pattern similarities and to investigate phylogenetic relationships among the genotyped strains. The AFLP method was compared with two additional DNA-based typing methods, pulsed-field gel electrophoresis (PFGE) using SmaI and restriction fragment length polymorphism analysis on PCR products (PCR-RFLP) of theflaA and flaB genes. We found that AFLP analysis of C. jejuni strains is a rapid method that offers better discriminatory power than do both PFGE and PCR-RFLP. AFLP and, to a lesser extent, PCR-RFLP could differentiate strains within the same PFGE profiles, which also makes PCR-RFLP an alternative to PFGE. We were able to clearly distinguish 9 of 10 recognized outbreaks by AFLP and to identify similarities among outbreak and sporadic strains. Therefore, AFLP is suitable for epidemiological surveillance ofC. jejuni and will be an excellent tool for source identification in outbreak situations.


2003 ◽  
Vol 69 (11) ◽  
pp. 6386-6392 ◽  
Author(s):  
Delphine Paillard ◽  
Véronique Dubois ◽  
Robert Duran ◽  
Fany Nathier ◽  
Catherine Guittet ◽  
...  

ABSTRACT A molecular method based on restriction fragment length polymorphism (RFLP) of PCR-amplified fragments of the 23S rRNA gene was designed to rapidly identify Listeria strains to the species level. Two fragments (S1, 460 bp, and S2, 890 bp) were amplified from boiled DNA. S2 was cut with the restriction enzymes XmnI or CfoI and, if needed, S1 was digested by either AluI or ClaI. This method was first optimized with six reference strains and then applied to 182 isolates collected from effluents of treatment plants. All isolates were also identified by the API Listeria kit, hemolysis, and phosphatidylinositol-specific phospholipase C production (PI-PLC) on ALOA medium. The PCR-RFLP method unambiguously identified 160 environmental strains, including 131 in concordance with the API system, and revealed that 22 isolates were mixed cultures of Listeria monocytogenes and Listeria innocua. Discrepant results were resolved by a multiplex PCR on the iap gene, which confirmed the PCR-RFLP data for 49 of the 51 discordances, including the 22 mixed cultures. Sequencing of the 16S rRNA gene for 12 selected strains and reconstruction of a phylogenetic tree validated the molecular methods, except for two unclassifiable strains. The 158 single identifiable isolates were 92 L. monocytogenes (including seven nonhemolytic and PI-PLC-negative strains), 61 L. innocua, 4 Listeria seeligeri, and 1 Listeria welshimeri strain. The PCR-RFLP method proposed here provides rapid, easy-to-use, inexpensive, and reliable identification of the six Listeria species. Moreover, it can detect mixtures of Listeria species and thus is particularly adapted to environmental and food microbiology.


2004 ◽  
Vol 70 (8) ◽  
pp. 4468-4477 ◽  
Author(s):  
Cinta Rachman ◽  
Petia Kabadjova ◽  
Rosica Valcheva ◽  
Hervé Prévost ◽  
Xavier Dousset

ABSTRACT The genus Carnobacterium is currently divided into the following eight species: Carnobacterium piscicola, C. divergens, C. gallinarum, C. mobile, C. funditum, C. alterfunditum, C. inhibens, and C. viridans. An identification tool for the rapid differentiation of these eight Carnobacterium species was developed, based on the 16S-23S ribosomal DNA (rDNA) intergenic spacer region (ISR). PCR-restriction fragment length polymorphism (PCR-RFLP) analysis of this 16S-23S rDNA ISR was performed in order to obtain restriction profiles for all of the species. Three PCR amplicons, which were designated small ISR (S-ISR), medium ISR (M-ISR), and large ISR (L-ISR), were obtained for all Carnobacterium species. The L-ISR sequence revealed the presence of two tRNA genes, tRNAAla and tRNAIle, which were separated by a spacer region that varied from 24 to 38 bp long. This region was variable among the species, allowing the design of species-specific primers. These primers were tested and proved to be species specific. The identification method based on the 16S-23S rDNA ISR, using PCR-RFLP and specific primers, is very suitable for the rapid low-cost identification and discrimination of all of the Carnobacterium species from other phylogenetically related lactic acid bacteria.


1999 ◽  
Vol 37 (10) ◽  
pp. 3198-3203 ◽  
Author(s):  
Ruth Grady ◽  
Meeta Desai ◽  
Gael O’Neill ◽  
Barry Cookson ◽  
John Stanley

Fluorescent amplified-fragment length polymorphism (FAFLP) analysis was investigated for its ability to identify and subtype isolates of an epidemic methicillin-resistant phage type of Staphylococcus aureus, EMRSA-15. These isolates were also characterized by PCR-restriction fragment length polymorphism (PCR-RFLP) of the coagulase gene and pulsed-field gel electrophoresis (PFGE). For FAFLP, DNA was double digested with restriction enzymes ApaI plusTaqI or EcoRI plus MseI. Site-specific adaptors were ligated to one or the other set of restriction fragments, and PCR amplification was carried out with adaptor-specific primers. Amplified fragments separated on an ABI 377 automated sequencer and analyzed with Genescan version 2.1 software generated FAFLP profiles for all the isolates. The presence or absence of fragments was scored, similarity coefficients were calculated, and UPGMA (unweighted pair group method using arithmatic averages) cluster analysis was performed. Either enzyme-primer combination readily differentiated EMRSA-15 from other methicillin-resistant S. aureus (MRSA) isolates and also revealed heterogeneity within the phage type. The discriminatory power of FAFLP was high. By combining both enzyme-primer data sets, 24 isolates were divided into 11 profiles. PCR-RFLP did not discriminate among these EMRSA-15 isolates. PFGE could discriminate well between isolates but was not as reproducible as FAFLP. All S. aureus and MRSA isolates in this study were typeable by FAFLP, which was easy to perform, robust, and reproducible, with evident potential to subtype MRSA for purposes of hospital infection control.


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