scholarly journals Cultivation-Independent Characterization of Methylobacterium Populations in the Plant Phyllosphere by Automated Ribosomal Intergenic Spacer Analysis

2008 ◽  
Vol 74 (7) ◽  
pp. 2218-2228 ◽  
Author(s):  
Claudia Knief ◽  
Lisa Frances ◽  
Franck Cantet ◽  
Julia A. Vorholt
Keyword(s):  
Intergenic Spacer ◽  
23S Rrna ◽  
Rrna Gene ◽  
Length Variation ◽  
Ribosomal Intergenic Spacer ◽  
Pcr Products ◽  
23S Rrna Gene ◽  
Reverse Primer ◽  
Insight Into

ABSTRACT Bacteria of the genus Methylobacterium are widespread in the environment, but their ecological role in ecosystems, such as the plant phyllosphere, is not very well understood. To gain better insight into the distribution of different Methylobacterium species in diverse ecosystems, a rapid and specific cultivation-independent method for detection of these organisms and analysis of their community structure is needed. Therefore, 16S rRNA gene-targeted primers specific for this genus were designed and evaluated. These primers were used in PCR in combination with a reverse primer that binds to the tRNAAla gene, which is located upstream of the 23S rRNA gene in the 16S-23S intergenic spacer (IGS). PCR products that were of different lengths were obtained due to the length heterogeneity of the IGS of different Methylobacterium species. This length variation allowed generation of fingerprints of Methylobacterium communities in environmental samples by automated ribosomal intergenic spacer analysis. The Methylobacterium communities on leaves of different plant species in a natural field were compared using this method. The new method allows rapid comparisons of Methylobacterium communities and is thus a useful tool to study Methylobacterium communities in different ecosystems.

scholarly journals Molecular characterization of a ceftriaxone-resistant Neisseria gonorrhoeae strain found in Switzerland: a case report

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Konrad Egli ◽  
Anna Roditscheff ◽  
Ursula Flückiger ◽  
Martin Risch ◽  
Lorenz Risch ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
23S Rrna ◽  
Rrna Gene ◽  
Limited Information ◽  
Specific Pcr ◽  
Appropriate Treatment ◽  
23S Rrna Gene ◽  
Allele Type ◽  
Ciprofloxacin Resistance

Abstract Background The resistance of Neisseria gonorrhoeae to ceftriaxone is unusual in Switzerland. The underlying genotype responsible for resistance is suspected to be novel. Generally, resistance in Neisseria gonorrhoeae (Ng) involves a comprehensive set of genes with many different mutations leading to resistance to different β-lactams and fluoroquinolones. Case presentation A patient had a positive result from specific PCR for Ng. We routinely culture all clinical specimens with a positive NG-PCR. In this particular case, we isolated a strain with resistance to ceftriaxone in Switzerland. A total of seven different genes (penA, ponA, porinB, mtr, gyrA, parC, 23S rRNA gene) in this strain were partially sequenced for comparison with phenotypic susceptibility testing. Interestingly, two different mutations in the porinB gene were observed, and data on this gene are limited. Information on the identified allele type of the penA gene is very limited as well. Three different mutations of parC and gyrA that correlate with ciprofloxacin resistance were found. The combination of ceftriaxone and ciprofloxacin resistance makes an appropriate treatment difficult to obtain due to multidrug resistance. Conclusion The combined results for all genes show the appearance of new mutations in central Europe either due to worldwide spread or the emergence of new genetic combinations of mutations.

scholarly journals Genotypic Characterization of Clarithromycin-Resistant and -Susceptible Helicobacter pylori Strains from the Same Patient Demonstrates Existence of Two Unrelated Isolates

1998 ◽  
Vol 36 (9) ◽  
pp. 2730-2731 ◽  
Author(s):  
Ge Wang ◽  
Qin Jiang ◽  
Diane E. Taylor
Keyword(s):  
Helicobacter Pylori ◽  
Gel Electrophoresis ◽  
Genomic Dna ◽  
Pulsed Field Gel Electrophoresis ◽  
23S Rrna ◽  
Rrna Gene ◽  
Clarithromycin Resistance ◽  
23S Rrna Gene ◽  
Mode Of Development

Clarithromycin-susceptible and clarithromycin-resistantHelicobacter pylori isolates from the same patient were investigated for the mode of development and mechanism of clarithromycin resistance. The clarithromycin-resistant strain UA1182 harbors homozygous A-to-G mutations at position 2143 in both copies of the 23S rRNA gene and has a phenotype of resistance to clarithromycin and clindamycin but no significant resistance to streptogramin B. Pulsed-field gel electrophoresis patterns of NruI- andNotI-digested genomic DNA from the Clas and Clar isolates demonstrated that they are genetically distinct, suggesting that the development of clarithromycin resistance is not from the mutation of the existing Clas strain but from a completely new strain.

scholarly journals Presence of a novel 16S–23S rRNA gene intergenic spacer insert in Bradyrhizobium canariense strains

2007 ◽  
Vol 269 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Vera Safronova ◽  
Elena Chizhevskaya ◽  
Simonetta Bullitta ◽  
Evgeny Andronov ◽  
Andrei Belimov ◽  
...  
Keyword(s):  
Intergenic Spacer ◽  
23S Rrna ◽  
Rrna Gene ◽  
23S Rrna Gene

scholarly journals 16S–23S rRNA Gene Intergenic Spacer Region Variability Helps Resolve Closely Related Sphingomonads

2016 ◽  
Vol 7 ◽  
Author(s):  
Sima Tokajian ◽  
Nahla Issa ◽  
Tamara Salloum ◽  
Joe Ibrahim ◽  
Maya Farah
Keyword(s):  
Intergenic Spacer ◽  
23S Rrna ◽  
Rrna Gene ◽  
Intergenic Spacer Region ◽  
23S Rrna Gene

scholarly journals Geographic Distribution and Genetic Diversity of Ceanothus-Infective FrankiaStrains

1999 ◽  
Vol 65 (4) ◽  
pp. 1378-1383 ◽  
Author(s):  
Nancy J. Ritchie ◽  
David D. Myrold
Keyword(s):  
Root Nodules ◽  
Intergenic Spacer ◽  
Taxonomic Diversity ◽  
Molecular Techniques ◽  
23S Rrna ◽  
Rrna Gene ◽  
Sample Collection ◽  
Pcr Product ◽  
Pcr Rflp ◽  
23S Rrna Gene

ABSTRACT Little is known about Ceanothus-infectiveFrankia strains because no Frankia strains that can reinfect the host plants have been isolated fromCeonothus spp. Therefore, we studied the diversity of theCeonothus-infective Frankia strains by using molecular techniques. Frankia strains inhabiting root nodules of nine Ceanothus species were characterized. The Ceanothus species used represent the taxonomic diversity and geographic range of the genus; therefore, the breadth of the diversity of Frankia strains that infectCeanothus spp. was studied. DNA was amplified directly from nodular material by using the PCR. The amplified region included the 3′ end of the 16S rRNA gene, the intergenic spacer, and a large portion of the 23S rRNA gene. A series of restriction enzyme digestions of the PCR product allowed us to identify PCR-restriction fragment length polymorphism (RFLP) groups among theCeanothus-infective Frankia strains tested. Twelve different enzymes were used, which resulted in four different PCR-RFLP groups. The groups did not follow the taxonomic lines of the Ceanothus host species. Instead, theFrankia strains present were related to the sample collection locales.

Sign in / Sign up

Export Citation Format

Share Document