Characterization of natural populations of Nitrobacter spp. using PCR/RFLP analysis of the ribosomal intergenic spacer

1992 ◽  
Vol 157 (2) ◽  
pp. 107-115 ◽  
Author(s):  
Elisabeth Navarro ◽  
Pascal Simonet ◽  
Philippe Normand ◽  
René Bardin
2006 ◽  
Vol 106 (3) ◽  
pp. 297-306 ◽  
Author(s):  
A. Llorens ◽  
M.J. Hinojo ◽  
R. Mateo ◽  
M.T. González-Jaén ◽  
F.M. Valle-Algarra ◽  
...  

2002 ◽  
Vol 92 (4) ◽  
pp. 406-416 ◽  
Author(s):  
Barry M. Pryor ◽  
Themis J. Michailides

Alternaria isolates were obtained from various pistachio tissues collected in five orchards in California. For all isolates, morphological characteristics of the colony and sporulation apparatus were determined and compared with those of representative isolates of A. alternata, A. tenuissima, A. arborescens, and A. infectoria. A selection of the pistachio isolates and the representative Alternaria isolates were evaluated for pathogenicity to pistachio. Molecular characteristics of these isolates were determined using random amplified polymorphism DNA (RAPD) analysis, polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis of nuclear intergenic spacer rDNA, and sequence analysis of nuclear internal transcribed spacer (ITS) rDNA. Based on morphological characteristics, the pistachio isolates were grouped as identical or very similar to either A. alternata, A. tenuissima, A. arborescens, or A. infectoria. Isolates from the alternata, tenuissima, and arborescens species-groups were pathogenic to pistachio and no significant differences in pathogenicity were observed. Isolates from the infectoria species-group were only weakly pathogenic to pistachio. Based on cluster analysis of RAPD and PCR-RFLP data, three distinct clusters were evident; the infectoria cluster, the arborescens cluster, and a combined alternata/tenuissima cluster. Based on analysis of ITS sequence data, the infectoria species-group was phylogenetically distinct from the other species-groups. Isolates of the alternata, tenuissima, and arborescens species-groups comprised a monophyletic clade in which the three species-groups could not be further resolved.


2020 ◽  
Author(s):  
Mansoor Kodori ◽  
Zohreh Ghalavand ◽  
Abbas Yadegar ◽  
Gita Eslami ◽  
Masoumeh Azimirad ◽  
...  

Abstract Background: Clostridioides difficile is the main cause of healthcare-associated diarrhea worldwide. It is proposed that certain C. difficile toxinotypes with distinct pathogenicity locus (PaLoc) variants are associated with disease severity and outcomes. Additionally, few studies have described the common C. difficile toxinotypes, and also little is known about the tcdC variants in Iranian isolates. We characterized the toxinotypes and the tcdC genotypes from a collection of Iranian clinical C. difficile tcdA+B+ isolates with known ribotypes (RTs).Methods: Fifty C. difficile isolates with known RTs and carrying the tcdA and tcdB toxin genes were analyzed. Toxinotyping was carried out based on a PCR-RFLP analysis of a 19.6 kb region encompassing the PaLoc. Genetic diversity of the tcdC gene was determined by the sequencing of the gene.Results: Of the 50 C. difficile isolates investigated, five distinct toxinotypes were recognized. Toxinotypes 0 (33/50, 66%) and V (11/50, 22%) were the most frequently found. C. difficile isolates of the toxinotype 0 mostly belonged to RT 001 (12/33, 36.4%), whereas toxinotype V consisted of RT 126 (9/11, 81.8%). The tcdC sequencing showed six variants (35/50, 70%); tcdC-sc3 (24%), tcdC-A (22%), tcdC-sc9 (18%), tcdC-B (2%), tcdC-sc14 (2%), and tcdC-sc15 (2%). The remaining isolates were wild-types (15/50, 30%) in the tcdC gene.Conclusions: The present study demonstrates that the majority of clinical tcdA+B+ isolates of C. difficile frequently harbor tcdC genetic variants. We also found that the RT 001/ toxinotype 0 and the RT 126/ toxinotype V are the most common types among Iranian isolates. Further studies are needed to investigate the putative association of various tcdC genotypes with CDI severity and its recurrence.


2011 ◽  
Vol 51 (No. 2) ◽  
pp. 94-99 ◽  
Author(s):  
S.D. Stoneberg Holt ◽  
L. Horová ◽  
P. Bureš ◽  
J. Janeček ◽  
V. Černoch

The characterization of crop cultivars (varieties) will come to depend increasingly on molecular characters in addition to traditional morphological and agronomic characters. Three cultivars of Kentucky bluegrass (Poa pratensis L.), developed by the Plant Breeding Station Hladké Životice (PBHŽ), were characterized using sequences and PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism) patterns from the non-coding plastid trnL-F region (trnL intron, 549 bp, and trnL-trnF intergenic spacer [IGS], 344 to 364 bp). These characters could be readily and repeatably determined not only for mature plants, but also for seedlings (less than 12 weeks old), which are difficult to distinguish morphologically. The method is quick and sensitive. When restricted with a combination of BsaJ I and Bsm I, cultivar Slezanka has one major band, Moravanka has two, and Harmonie has three. When restricted with Alu I, the heaviest band migrates most slowly for Slezanka. It is expected that many Kentucky bluegrass cultivars will share the same trnL-F sequence, so these characters alone are not sufficient for variety identification.


2011 ◽  
Vol 81 (1) ◽  
pp. 21-25 ◽  
Author(s):  
Hassan Momtaz ◽  
Saadat Moshkelani

Leptospira is recognized as an important public health problem worldwide, especially in tropical countries, and is a common cause of abortion in dairy and beef herds. The aim of the present study was to detect and characterize Leptospira as the causative agent of abortion in cattle using a PCR-RFLP in Chaharmahal va Bakhtiari and Isfahan provinces, Iran. A total of 220 bovine aborted foetuses and 120 vaginal discharges from an aborted calf were collected from 64 commercial dairy herds. After isolation of 60 Leptospira spp. from samples, RFLP analysis was carried out with HindIII and HaeIII restriction enzymes in reference strains and isolated for characterization. In a total of 340 specimens, 46 (20.9%) and 14 (11.66%) were identified positive for Leptospira spp. from aborted bovine foetuses and vaginal discharges, respectively. The present results also suggest that L. interrogans serovar hardjo has the highest prevalence in the region under study and L. hardjo is a major pathogen causing bovine abortion in Chaharmahal va Bakhtiari and Isfahan provinces of Iran.


Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1058 ◽  
Author(s):  
Mariangie Castillo ◽  
Emanuel da Silva ◽  
José S. Câmara ◽  
Mahnaz Khadem

The quality and typical characteristic of wines depends, among other factors, on the volatile organic metabolites (VOMs) that are biosynthesized by yeasts, mainly Saccharomyces cerevisiae species. The yeast strain influences the diversity and proportions of the VOMs produced during the fermentation process, as the genetic predisposition of the strains is a by-product of selective adaptation to the ecosystem. The present work reports the characterization of S. cerevisiae strains isolated from grape must, used in the Demarcated Region of Madeira (DRM) for winemaking. Yeast species were identified by amplification and by restriction fragment length polymorphism (RFLP) analysis of the region 5.8S-internal transcribed spacers (PCR-RFLP of 5.8S-ITS) of ribosomal DNA (rDNA). The strains identification was performed by analyzing the RFLP pattern of mitochondrial DNA (RFLP-mtDNA). The representative strains were selected for the characterization of the volatile profile through headspace solid-phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS) analysis. A total of 77 VOMs were identified. Higher alcohols, esters, and fatty acids were the major chemical families representing 63%, 16%, and 9%, respectively, in strain A and 54%, 23%, and 15% in strain B. The results indicate the influence of the strain metabolism in the production of VOMs, many of which probably participate in the aroma of the corresponding wines.


Genome ◽  
2018 ◽  
Vol 61 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Frédérique Bélanger-Lépine ◽  
Christelle Leung ◽  
Hélène Glémet ◽  
Bernard Angers

The ribosomal intergenic spacer (IGS), responsible for the rate of transcription of rRNA genes, is associated with the growth and fecundity of individuals. A previous study of IGS length variants in a yellow perch (Perca flavescens) population revealed the presence of two predominant alleles differing by 1 kb due to variation in the number of repeat units. This study aims to assess whether length variation of IGS is the result of selection in natural populations. Length variation of IGS and 11 neutral microsatellite loci were assessed in geographically distant yellow perch populations. Most populations displayed the very same IGS alleles; they did not differ in frequencies among populations and the FST was not significantly different from zero. In contrast, diversity at microsatellite loci was high and differed among populations (FST = 0.18). Selection test based on FST identified IGS as a significant outlier from neutral expectations for population differentiation. Heterozygote excess was also detected in one specific cohort, suggesting temporal variation in the selection regime. While the exact mechanism remains to be specified, together the results of this study support the contention that balancing selection is acting to maintain two distinct IGS alleles in natural fish populations.


Sign in / Sign up

Export Citation Format

Share Document