analyses of rRNA sequences can identify so-called signature sequence motifs on various taxonomic levels which are targets for an evolutionary-based identification (Giovannoni et al. 1988, Manz et al. 1992, Amann et al. 1995). In addition, the development of robust DNA cloning techniques and the polymerase chain reaction (PCR) have facilitated higher resolution analyses of more complex communities using 16S rRNA sequence analysis. It has been proposed that the highly variable, selectively neutral, intergenic spacer regions between the 5S and 16S or 16S and 23S rRNA genes might provide better targets (Aakra et al. 1999, Fisher and Triplett 1999). For community structure analysis, however, it seems rather unlikely that other parts of the bacterial genome could fully replace the 16S rRNA gene as target sites due to insufficient sequence information for comparisons.

2003 ◽  
pp. 220-220
Keyword(s):  
16S Rrna ◽  
Bacterial Genome ◽  
Intergenic Spacer ◽  
Rrna Genes ◽  
23S Rrna ◽  
Rrna Gene ◽  
Sequence Information ◽  
Sequence Motifs ◽  
16S Rrna Sequence ◽  
23S Rrna Genes

scholarly journals Species-Specific PCR for Identification of Common Contaminant Mollicutes in Cell Culture

2001 ◽  
Vol 67 (7) ◽  
pp. 3195-3200 ◽  
Author(s):  
Fanrong Kong ◽  
Gregory James ◽  
Susanna Gordon ◽  
Anna Zelynski ◽  
Gwendolyn L. Gilbert
Keyword(s):  
16S Rrna ◽  
Cell Cultures ◽  
Bacterial Species ◽  
Intergenic Spacer ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
23S Rrna ◽  
Rrna Gene ◽  
Specific Pcr ◽  
Species Specific

ABSTRACT Mycoplasma arginini, M. fermentans, M. hyorhinis, M. orale, and Acholeplasma laidlawii are the members of the class Mollicutes most commonly found in contaminated cell cultures. Previous studies have shown that the published PCR primer pairs designed to detect mollicutes in cell cultures are not entirely specific. The 16S rRNA gene, the 16S-23S rRNA intergenic spacer region, and the 5′ end of the 23S rRNA gene, as a whole, are promising targets for design of mollicute species-specific primer pairs. We analyzed the 16S rRNA genes, the 16S-23S rRNA intergenic spacer regions, and the 5′ end of the 23S rRNA genes of these mollicutes and developed PCR methods for species identification based on these regions. Using high melting temperatures, we developed a rapid-cycle PCR for detection and identification of contaminant mollicutes. Previously published, putative mollicute-specific primers amplified DNA from 73 contaminated cell lines, but the presence of mollicutes was confirmed by species-specific PCR in only 60. Sequences of the remaining 13 amplicons were identified as those of gram-positive bacterial species. Species-specific PCR primers are needed to confirm the presence of mollicutes in specimens and for identification, if required.

scholarly journals Discordant 16S and 23S rRNA Gene Phylogenies for the Genus Helicobacter: Implications for Phylogenetic Inference and Systematics

2005 ◽  
Vol 187 (17) ◽  
pp. 6106-6118 ◽  
Author(s):  
Floyd E. Dewhirst ◽  
Zeli Shen ◽  
Michael S. Scimeca ◽  
Lauren N. Stokes ◽  
Tahani Boumenna ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Gene Sequence ◽  
Sequence Data ◽  
Rrna Genes ◽  
23S Rrna ◽  
Rrna Gene ◽  
Rrna Gene Sequence ◽  
23S Rrna Gene ◽  
23S Rrna Genes

ABSTRACT Analysis of 16S rRNA gene sequences has become the primary method for determining prokaryotic phylogeny. Phylogeny is currently the basis for prokaryotic systematics. Therefore, the validity of 16S rRNA gene-based phylogenetic analyses is of fundamental importance for prokaryotic systematics. Discrepancies between 16S rRNA gene analyses and DNA-DNA hybridization and phenotypic analyses have been noted in the genus Helicobacter. To clarify these discrepancies, we sequenced the 23S rRNA genes for 55 helicobacter strains representing 41 taxa (>2,700 bases per sequence). Phylogenetic-tree construction using neighbor-joining, parsimony, and maximum likelihood methods for 23S rRNA gene sequence data yielded stable trees which were consistent with other phenotypic and genotypic methods. The 16S rRNA gene sequence-derived trees were discordant with the 23S rRNA gene trees and other data. Discrepant 16S rRNA gene sequence data for the helicobacters are consistent with the horizontal transfer of 16S rRNA gene fragments and the creation of mosaic molecules with loss of phylogenetic information. These results suggest that taxonomic decisions must be supported by other phylogenetically informative macromolecules, such as the 23S rRNA gene, when 16S rRNA gene-derived phylogeny is discordant with other credible phenotypic and genotypic methods. This study found Wolinella succinogenes to branch with the unsheathed-flagellum cluster of helicobacters by 23S rRNA gene analyses and whole-genome comparisons. This study also found intervening sequences (IVSs) in the 23S rRNA genes of strains of 12 Helicobacter species. IVSs were found in helices 10, 25, and 45, as well as between helices 31′ and 27′. Simultaneous insertion of IVSs at three sites was found in H. mesocricetorum.

scholarly journals The Internal Transcribed Spacer Region, a New Tool for Use in Species Differentiation and Delineation of Systematic Relationships within the Campylobacter Genus

2010 ◽  
Vol 76 (10) ◽  
pp. 3071-3081 ◽  
Author(s):  
Si Ming Man ◽  
Nadeem O. Kaakoush ◽  
Sophie Octavia ◽  
Hazel Mitchell
Keyword(s):  
16S Rrna ◽  
Internal Transcribed Spacer ◽  
Its Region ◽  
Rrna Genes ◽  
23S Rrna ◽  
Species Differentiation ◽  
Rrna Gene ◽  
23S Rrna Gene ◽  
Systematic Relationships ◽  
23S Rrna Genes

ABSTRACT The Campylobacter genus consists of a number of important human and animal pathogens. Although the 16S rRNA gene has been used extensively for detection and identification of Campylobacter species, there is currently limited information on the 23S rRNA gene and the internal transcribed spacer (ITS) region that lies between the 16S and 23S rRNA genes. We examined the potential of the 23S rRNA gene and the ITS region to be used in species differentiation and delineation of systematic relationships for 30 taxa within the Campylobacter genus. The ITS region produced the highest mean pairwise percentage difference (35.94%) compared to the 16S (5.34%) and 23S (7.29%) rRNA genes. The discriminatory power for each region was further validated using Simpson's index of diversity (D value). The D values were 0.968, 0.995, and 0.766 for the ITS region and the 23S and 16S rRNA genes, respectively. A closer examination of the ITS region revealed that Campylobacter concisus, Campylobacter showae, and Campylobacter fetus subsp. fetus harbored tRNA configurations not previously reported for other members of the Campylobacter genus. We also observed the presence of strain-dependent intervening sequences in the 23S rRNA genes. Neighbor-joining trees using the ITS region revealed that Campylobacter jejuni and Campylobacter coli strains clustered in subgroups, which was not observed in trees derived from the 16S or 23S rRNA gene. Of the three regions examined, the ITS region is by far the most cost-effective region for the differentiation and delineation of systematic relationships within the Campylobacter genus.

scholarly journals Molecular Evidence of Chlamydia-Like Organisms in the Feces of Myotis daubentonii Bats

2016 ◽  
Vol 83 (2) ◽  
Author(s):  
K. Hokynar ◽  
E. J. Vesterinen ◽  
T. M. Lilley ◽  
A. T. Pulliainen ◽  
S. J. Korhonen ◽  
...  
Keyword(s):  
16S Rrna ◽  
Sequence Similarity ◽  
Pcr Amplification ◽  
Rrna Genes ◽  
23S Rrna ◽  
Molecular Evidence ◽  
Rrna Gene ◽  
16S Rrna Sequence ◽  
Content Type ◽  
Pcr Targeting

ABSTRACT Chlamydia-like organisms (CLOs) are recently identified members of the Chlamydiales order. CLOs share intracellular lifestyles and biphasic developmental cycles, and they have been detected in environmental samples as well as in various hosts such as amoebae and arthropods. In this study, we screened bat feces for the presence of CLOs by molecular analysis. Using pan-Chlamydiales PCR targeting the 16S rRNA gene, Chlamydiales DNA was detected in 54% of the specimens. PCR amplification, sequencing, and phylogenetic analysis of the 16S rRNA and 23S rRNA genes were used to classify positive specimens and infer their phylogenetic relationships. Most sequences matched best with Rhabdochlamydia species or uncultured Chlamydia sequences identified in ticks. Another set of sequences matched best with sequences of the Chlamydia genus or uncultured Chlamydiales from snakes. To gain evidence of whether CLOs in bat feces are merely diet borne, we analyzed insects trapped from the same location where the bats foraged. Interestingly, the CLO sequences resembling Rhabdochlamydia spp. were detected in insect material as well, but the other set of CLO sequences was not, suggesting that this set might not originate from prey. Thus, bats represent another potential host for Chlamydiales and could harbor novel, previously unidentified members of this order. IMPORTANCE Several pathogenic viruses are known to colonize bats, and recent analyses indicate that bats are also reservoir hosts for bacterial genera. Chlamydia-like organisms (CLOs) have been detected in several animal species. CLOs have high 16S rRNA sequence similarity to Chlamydiaceae and exhibit similar intracellular lifestyles and biphasic developmental cycles. Our study describes the frequent occurrence of CLO DNA in bat feces, suggesting an expanding host species spectrum for the Chlamydiales. As bats can acquire various infectious agents through their diet, prey insects were also studied. We identified CLO sequences in bats that matched best with sequences in prey insects but also CLO sequences not detected in prey insects. This suggests that a portion of CLO DNA present in bat feces is not prey borne. Furthermore, some sequences from bat droppings not originating from their diet might well represent novel, previously unidentified members of the Chlamydiales order.

scholarly journals Case of Localized Recombination in 23S rRNA Genes from Divergent Bradyrhizobium Lineages Associated with Neotropical Legumes

2001 ◽  
Vol 67 (5) ◽  
pp. 2076-2082 ◽  
Author(s):  
Matthew A. Parker
Keyword(s):  
16S Rrna ◽  
Barro Colorado Island ◽  
Mosaic Structure ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
23S Rrna ◽  
Close Relative ◽  
Rrna Gene ◽  
Enzyme Electrophoresis ◽  
16S Rrna Sequence

ABSTRACT Enzyme electrophoresis and rRNA sequencing were used to analyze relationships of Bradyrhizobium sp. nodule bacteria from four papilionoid legumes (Clitoria javitensis, Erythrina costaricensis, Rhynchosia pyramidalis, and Desmodium axillare) growing on Barro Colorado Island (BCI), Panama. Bacteria with identical multilocus allele profiles were commonly found in association with two or more legume genera. Among the 16 multilocus genotypes (electrophoretic types [ETs]) detected, six ETs formed a closely related cluster that included isolates from all four legume taxa. Bacteria from two other BCI legumes (Platypodium andMachaerium) sampled in a previous study were also identical to certain ETs in this group. Isolates from different legume genera that had the same ET had identical nucleotide sequences for both a 5′ portion of the 23S rRNA and the nearly full-length 16S rRNA genes. These results suggest that Bradyrhizobium genotypes with low host specificity may be prevalent in this tropical forest. Parsimony analysis of 16S rRNA sequence variation indicated that most isolates were related to Bradyrhizobium japonicum USDA 110, although one ET sampled from C. javitensis had a 16S rRNA gene highly similar to that of Bradyrhizobium elkaniiUSDA 76. However, this isolate displayed a mosaic structure within the 5′ 23S rRNA region: one 84-bp segment was identical to that of BCI isolate Pe1-3 (a close relative of B. japonicum USDA 110, based on 16S rRNA data), while an adjacent 288-bp segment matched that of B. elkanii USDA 76. This mosaic structure is one of the first observations suggesting recombination in nature betweenBradyrhizobium isolates related to B. japonicumversus B. elkanii.

scholarly journals Development of a Microelectronic Chip Array for High-Throughput Genotyping of Helicobacter Species and Screening for Antimicrobial Resistance

2005 ◽  
Vol 10 (3) ◽  
pp. 235-245 ◽  
Author(s):  
James Z. Xing ◽  
Chris Clarke ◽  
Lijun Zhu ◽  
Stephan Gabos
Keyword(s):  
Antimicrobial Resistance ◽  
16S Rrna ◽  
Tetracycline Resistance ◽  
Rrna Genes ◽  
23S Rrna ◽  
Rrna Gene ◽  
Nucleotide Polymorphisms ◽  
23S Rrna Gene ◽  
23S Rrna Genes ◽  
H Pylori

A microelectronic array assay was developed to specifically genotype Helicobacter pylori versus Helicobacter heilmannii and to determine antimicrobial resistance. Helicobacter 16S rRNA and 23S rRNA genes were specifically generated with Helicobacter genus-specific primers, respectively. The single-nucleotide polymorphisms (SNPs) in 16S rRNA, 268T specific in the H. pylori sequence, and 263A specific in H. heilmannii were used as molecular markers for identification of H. pylori and H. heilmannii, respectively. A triple-base-pair resistant mutation, AGA965-967TTC in 16S rRNA, is known to be responsible for H. pylori tetracycline resistance and was detected to identify resistant strains. H. pylori macrolide resistance was determined by the identification of 3 defined mutations in the 23S rRNA gene using the same method. The assay could be directly used to detect H. pylori in feces. The assay performs multiple determinations, including identification of Helicobacter species and antibiotic resistances, on the same microelectronic platform and is highly amenable to the development of other DNA-based assays.

scholarly journals Spontaneous Erythromycin Resistance Mutation in a 23S rRNA Gene, rrlA, of the Extreme Thermophile Thermus thermophilus IB-21

2001 ◽  
Vol 183 (14) ◽  
pp. 4382-4385 ◽  
Author(s):  
Steven T. Gregory ◽  
Jamie H. D. Cate ◽  
Albert E. Dahlberg
Keyword(s):  
Genetic Manipulation ◽  
Thermus Thermophilus ◽  
Resistance Mutation ◽  
Rrna Genes ◽  
23S Rrna ◽  
Rrna Gene ◽  
Erythromycin Resistance ◽  
23S Rrna Gene ◽  
Resistant Mutants ◽  
23S Rrna Genes

ABSTRACT Spontaneous, erythromycin-resistant mutants of Thermus thermophilus IB-21 were isolated and found to carry the mutation A2058G in one of two 23S rRNA operons. The heterozygosity of these mutants indicates that A2058G confers a dominant or codominant phenotype in this organism. This mutation provides a valuable tool for the genetic manipulation of the 23S rRNA genes ofThermus.

scholarly journals Phylogenetic relationships within the family Halomonadaceae based on comparative 23S and 16S rRNA gene sequence analysis

2010 ◽  
Vol 60 (4) ◽  
pp. 737-748 ◽  
Author(s):  
Rafael R. de la Haba ◽  
David R. Arahal ◽  
M. Carmen Márquez ◽  
Antonio Ventosa
Keyword(s):  
16S Rrna ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
23S Rrna ◽  
Rrna Gene ◽  
Gene Sequences ◽  
The Family ◽  
23S Rrna Gene ◽  
Group 2 ◽  
Group 1

A phylogenetic study of the family Halomonadaceae was carried out based on complete 16S rRNA and 23S rRNA gene sequences. Several 16S rRNA genes of type strains were resequenced, and 28 new sequences of the 23S rRNA gene were obtained. Currently, the family includes nine genera (Carnimonas, Chromohalobacter, Cobetia, Halomonas, Halotalea, Kushneria, Modicisalibacter, Salinicola and Zymobacter). These genera are phylogenetically coherent except Halomonas, which is polyphyletic. This genus comprises two clearly distinguished clusters: group 1 includes Halomonas elongata (the type species) and the species Halomonas eurihalina, H. caseinilytica, H. halmophila, H. sabkhae, H. almeriensis, H. halophila, H. salina, H. organivorans, H. koreensis, H. maura and H. nitroreducens. Group 2 comprises the species Halomonas aquamarina, H. meridiana, H. axialensis, H. magadiensis, H. hydrothermalis, H. alkaliphila, H. venusta, H. boliviensis, H. neptunia, H. variabilis, H. sulfidaeris, H. subterranea, H. janggokensis, H. gomseomensis, H. arcis and H. subglaciescola. Halomonas salaria forms a cluster with Chromohalobacter salarius and the recently described genus Salinicola, and their taxonomic affiliation requires further study. More than 20 Halomonas species are phylogenetically not within the core constituted by the Halomonas sensu stricto cluster (group 1) or group 2 and, since their positions on the different phylogenetic trees are not stable, they cannot be recognized as additional groups either. In general, there is excellent agreement between the phylogenies based on the two rRNA gene sequences, but the 23S rRNA gene showed higher resolution in the differentiation of species of the family Halomonadaceae.

scholarly journals Identification of non-fermenting Gram-negative bacteria of clinical importance by an oligonucleotide array

2009 ◽  
Vol 58 (5) ◽  
pp. 596-605 ◽  
Author(s):  
Siou Cing Su ◽  
Mario Vaneechoutte ◽  
Lenie Dijkshoorn ◽  
Yu Fang Wei ◽  
Ya Lei Chen ◽  
...  
Keyword(s):  
Clinical Importance ◽  
Intergenic Spacer ◽  
16S Rrna Genes ◽  
Oligonucleotide Array ◽  
Rrna Genes ◽  
Universal Primers ◽  
23S Rrna ◽  
Rrna Gene ◽  
Nylon Membrane ◽  
Gram Negative

Many species of non-fermenting Gram-negative bacilli (non-fermenters) are important opportunistic and nosocomial pathogens. Identification of most species of non-fermenters by phenotypic characteristics can be difficult. In this study, an oligonucleotide array was developed to identify 38 species of clinically relevant non-fermenters. The method consisted of PCR-based amplification of 16S–23S rRNA gene intergenic spacer (ITS) regions using bacterial universal primers, followed by hybridization of the digoxigenin-labelled PCR products with oligonucleotide probes immobilized on a nylon membrane. A total of 398 strains, comprising 276 target strains (i.e. strains belonging to the 38 species to be identified) and 122 non-target strains (i.e. strains not included in the array), were analysed by the array. Four target strains (three reference strains and one clinical isolate) produced discrepant identification by array hybridization. Three of the four discordant strains were found to be correctly identified by the array, as confirmed by sequencing of the ITS and 16S rRNA genes, with the remaining one being an unidentified species. The sensitivity and specificity of the array for identification of non-fermenters were 100 and 96.7 %, respectively. In summary, the oligonucleotide array described here offers a very reliable method for identification of clinically relevant non-fermenters, with results being available within one working day.

scholarly journals rDNA analyses of planktonic heterocystous cyanobacteria, including members of the genera Anabaenopsis and Cyanospira The GenBank accession numbers of the 16S rDNA gene sequences reported in this paper are AY038032–AY038037.

Microbiology ◽  
2002 ◽  
Vol 148 (2) ◽  
pp. 481-496 ◽  
Author(s):  
Isabelle Iteman ◽  
Rosmarie Rippka ◽  
Nicole Tandeau de Marsac ◽  
Michael Herdman
Keyword(s):  
16S Rrna ◽  
16S Rdna ◽  
Genomic Sequence ◽  
Sequence Similarity ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
23S Rrna ◽  
Phylogenetic Position ◽  
Rrna Gene ◽  
Heterocystous Cyanobacteria

The taxonomic coherence and phylogenetic relationships of 11 planktonic heterocystous cyanobacterial isolates were examined by investigating two areas of the rRNA operon, the 16S rRNA gene (rrnS) and the internal transcribed spacer (ITS) located between the 16S rRNA and 23S rRNA genes. The rrnS sequences were determined for five strains, including representatives of Anabaena flos-aquae, Aphanizomenon flos-aquae, Nodularia sp. and two alkaliphilic planktonic members of the genera Anabaenopsis and Cyanospira, whose phylogenetic position was previously unknown. Comparison of the data with those previously published for individual groups of planktonic heterocystous cyanobacteria showed that, with the exception of members assigned to the genus Cylindrospermopsis, all the planktonic strains form a distinct subclade within the monophyletic clade of heterocystous cyanobacteria. Within this subclade five different phylogenetic clusters were distinguished. The phylogenetic groupings of Anabaena and Aphanizomenon strains within three of these clusters were not always consistent with their generic or specific assignments based on classical morphological definitions, and the high degree of sequence similarity between strains of Anabaenopsis and Cyanospira suggests that they may be assignable to a single genus. Ribotyping and additional studies performed on PCR amplicons of the 16S rDNA or the ITS for the 11 planktonic heterocystous strains demonstrated that they all contain multiple rrn operons and ITS regions of variable size. Finally, evidence is provided for intra-genomic sequence heterogeneity of the 16S rRNA genes within most of the individual isolates.

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