scholarly journals Molecular Characterization of the 16S rRNA Gene ofHelicobacter fennelliaeIsolated from Stools and Blood Cultures from Paediatric Patients in South Africa

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Heidi E. M. Smuts ◽  
Albert Joseph Lastovica
Keyword(s):  
South Africa ◽  
Phylogenetic Analysis ◽  
16S Rrna ◽  
South African ◽  
Rpob Gene ◽  
Australian Isolate ◽  
23S Rrna ◽  
Rrna Gene ◽  
Separate Branch ◽  
Primary Stem

Forty strains ofH. fennelliaecollected from paediatric blood and stool samples over an 18 year period at a children's hospital in Cape Town, South Africa, were amplified by PCR of the 16S rRNA. Two distinct genotypes ofH. fennelliaewere identified based on the phylogenetic analysis. This was confirmed by sequencing a portion of the beta subunit of the RNA polymerase (rpoB) gene. All isolates from South Africa clustered with a proposed novelHelicobacterstrain (accession number AF237612) isolated in Australia, while threeH. fennelliaetype strains from the northern hemisphere, NCTC 11612, LMG 7546 and CCUG 18820, formed a separate branch. A large (355bp) highly conserved intervening sequence (IVS) in the 16S rRNA was found in all isolates. Predicted secondary structures of the IVS from the 16S rRNA and 23S rRNA were characterised by a primary stem structure formed by base pairing of the 3′and 5′ends and internal loops and stems. This phylogenetic analysis is the largest undertaken ofH. fennelliae. The South AfricanH. fennelliaeisolates are closely related to an Australian isolate previously reported to be a possible novel species of Helicobacter. This study suggests that the latter is strain ofH. fennelliae.

scholarly journals Three novel lineages of ‘Candidatus Liberibacter africanus’ associated with native rutaceous hosts of Trioza erytreae in South Africa

2015 ◽  
Vol 65 (Pt_2) ◽  
pp. 723-731 ◽  
Author(s):  
Ronel Roberts ◽  
Emma T. Steenkamp ◽  
Gerhard Pietersen
Keyword(s):  
South Africa ◽  
Phylogenetic Analysis ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Sequence Data ◽  
Rrna Gene ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
Nucleotide Sequence Data ◽  
Trioza Erytreae

Greening disease of citrus in South Africa is associated with ‘Candidatus Liberibacter africanus’ (Laf), a phloem-limited bacterium vectored by the sap-sucking insect Trioza erytreae (Triozidae). Despite the implementation of control strategies, this disease remains problematic, suggesting the existence of reservoir hosts to Laf. The current study aimed to identify such hosts. Samples from 234 trees of Clausena anisata, 289 trees of Vepris lanceolata and 231 trees of Zanthoxylum capense were collected throughout the natural distribution of these trees in South Africa. Total DNA was extracted from samples and tested for the presence of liberibacters by a generic Liberibacter TaqMan real-time PCR assay. Liberibacters present in positive samples were characterized by amplifying and sequencing rplJ, omp and 16S rRNA gene regions. The identity of tree host species from which liberibacter sequences were obtained was verified by sequencing host rbcL genes. Of the trees tested, 33 specimens of Clausena, 17 specimens of Vepris and 10 specimens of Zanthoxylum tested positive for liberibacter. None of the samples contained typical citrus-infecting Laf sequences. Phylogenetic analysis of 16S rRNA gene sequences indicated that the liberibacters obtained from Vepris and Clausena had 16S rRNA gene sequences identical to that of ‘Candidatus Liberibacter africanus subsp. capensis’ (LafC), whereas those from Zanthoxylum species grouped separately. Phylogenetic analysis of the rplJ and omp gene regions revealed unique clusters for liberibacters associated with each tree species. We propose the following names for these novel liberibacters: ‘Candidatus Liberibacter africanus subsp. clausenae’ (LafCl), ‘Candidatus Liberibacter africanus subsp. vepridis’ (LafV) and ‘Candidatus Liberibacter africanus subsp. zanthoxyli’ (LafZ). This study did not find any natural hosts of Laf associated with greening of citrus. While native citrus relatives were shown to be infected with Laf-related liberibacters, nucleotide sequence data suggest that these are not alternative sources of Laf to citrus orchards, per se.

scholarly journals Multilocus sequence analysis of the family Halomonadaceae

2012 ◽  
Vol 62 (Pt_3) ◽  
pp. 520-538 ◽  
Author(s):  
Rafael R. de la Haba ◽  
M. Carmen Márquez ◽  
R. Thane Papke ◽  
Antonio Ventosa
Keyword(s):  
Phylogenetic Analysis ◽  
Sequence Analysis ◽  
16S Rrna ◽  
Halophilic Bacteria ◽  
Multilocus Sequence Analysis ◽  
23S Rrna ◽  
Rrna Gene ◽  
The Family ◽  
Micro Organisms ◽  
The Impact

Multilocus sequence analysis (MLSA) protocols have been developed for species circumscription for many taxa. However, at present, no studies based on MLSA have been performed within any moderately halophilic bacterial group. To test the usefulness of MLSA with these kinds of micro-organisms, the family Halomonadaceae, which includes mainly halophilic bacteria, was chosen as a model. This family comprises ten genera with validly published names and 85 species of environmental, biotechnological and clinical interest. In some cases, the phylogenetic relationships between members of this family, based on 16S rRNA gene sequence comparisons, are not clear and a deep phylogenetic analysis using several housekeeping genes seemed appropriate. Here, MLSA was applied using the 16S rRNA, 23S rRNA, atpA, gyrB, rpoD and secA genes for species of the family Halomonadaceae. Phylogenetic trees based on the individual and concatenated gene sequences revealed that the family Halomonadaceae formed a monophyletic group of micro-organisms within the order Oceanospirillales. With the exception of the genera Halomonas and Modicisalibacter, all other genera within this family were phylogenetically coherent. Five of the six studied genes (16S rRNA, 23S rRNA, gyrB, rpoD and secA) showed a consistent evolutionary history. However, the results obtained with the atpA gene were different; thus, this gene may not be considered useful as an individual gene phylogenetic marker within this family. The phylogenetic methods produced variable results, with those generated from the maximum-likelihood and neighbour-joining algorithms being more similar than those obtained by maximum-parsimony methods. Horizontal gene transfer (HGT) plays an important evolutionary role in the family Halomonadaceae; however, the impact of recombination events in the phylogenetic analysis was minimized by concatenating the six loci, which agreed with the current taxonomic scheme for this family. Finally, the findings of this study also indicated that the 16S rRNA, gyrB and rpoD genes were the most suitable genes for future taxonomic studies using MLSA within the family Halomonadaceae.

scholarly journals Taxonomy of the canine Mollicutes by 16S rRNA gene and 16S/23S rRNA intergenic spacer region sequence comparison

2004 ◽  
Vol 54 (2) ◽  
pp. 537-542 ◽  
Author(s):  
Victoria J. Chalker ◽  
Joe Brownlie
Keyword(s):  
Phylogenetic Analysis ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Sequence Comparison ◽  
Intergenic Spacer ◽  
23S Rrna ◽  
Rrna Gene ◽  
16S Rrna Gene Sequences ◽  
Intergenic Spacer Region ◽  
The 16S Rrna Gene

The taxonomy of canine Mollicutes is described, based on phylogenetic analysis of 16S rRNA gene and 16S/23S rRNA intergenic spacer (IGS) region sequences. The nucleotide sequences of the 16S rRNA gene of two untyped mycoplasmas and the IGS region of 11 Mycoplasma species were determined and used for phylogenetic analysis. The two untyped Mycoplasma strains, HRC 689 and VJC 358, were found to be distinct from all known canine mycoplasmas and all published mycoplasma 16S rRNA gene sequences.

scholarly journals Assessment of Genetic Diversity and Symbiotic Efficiency of Selected Rhizobia Strains Nodulating Lentil (Lens culinaris Medik.)

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 15
Author(s):  
Badreddine Sijilmassi ◽  
Abdelkarim Filali-Maltouf ◽  
Hassan Boulahyaoui ◽  
Aymane Kricha ◽  
Kenza Boubekri ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Phylogenetic Analysis ◽  
16S Rrna ◽  
Rhizobium Leguminosarum ◽  
Sequence Similarity ◽  
P Value ◽  
Rrna Gene ◽  
Research Station ◽  
Symbiotic Efficiency ◽  
Rhizobium Strains

A total of 14 Rhizobium strains were isolated from lentil accessions grown at the ICARDA experimental research station at Marchouch in Morocco and used for molecular characterization and symbiotic efficiency assessment. Individual phylogenetic analysis using the 16S rRNA gene, house-keeping genes rpoB, recA, and gyrB, and symbiotic genes nodD and nodA along with Multilocus Sequence Analysis (MLSA) of the concatenated genes (16S rRNA-rpoB-recA-gyrB) was carried out for the identification and clustering of the isolates. The symbiotic efficiency of the strains was assessed on three Moroccan lentil cultivars (Bakria, Chakkouf, and Zaria) based on the number of nodules, plant height, plant dry weight, and total nitrogen content in leaves. The results showed that the individual phylogenetic analysis clustered all the strains into Rhizobium laguerreae and Rhizobium leguminosarum with sequence similarity ranging from 94 to 100%, except one strain which clustered with Mesorhizobium huakuii with sequence similarity of 100%. The MLSA of the concatenated genes and the related percentages of similarity clustered these strains into two groups of Rhizobium species, with one strain as a new genospecies when applying the threshold of 96%. For symbiotic efficiency, the Bakria variety showed the best association with 10 strains compared to its non-inoculated control (p-value ≤ 0.05), followed by Chakkouf and Zaria. The present study concluded that the genetic diversity and the symbiotic efficiency of Rhizobium strains appeared to be mainly under the control of the lentil genotypes.

scholarly journals The Termite Group I Phylum Is Highly Diverse and Widespread in the Environment

2007 ◽  
Vol 73 (20) ◽  
pp. 6682-6685 ◽  
Author(s):  
Daniel P. R. Herlemann ◽  
Oliver Geissinger ◽  
Andreas Brune
Keyword(s):  
Phylogenetic Analysis ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Rrna Gene ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
Specific Primers ◽  
Environmental Distribution ◽  
Data Set ◽  
Group I

ABSTRACT The bacterial candidate phylum Termite Group I (TG-1) presently consists mostly of “Endomicrobia,” which are endosymbionts of flagellate protists occurring exclusively in the hindguts of termites and wood-feeding cockroaches. Here, we show that public databases contain many, mostly undocumented 16S rRNA gene sequences from other habitats that are affiliated with the TG-1 phylum but are only distantly related to “Endomicrobia.” Phylogenetic analysis of the expanded data set revealed several diverse and deeply branching lineages comprising clones from many different habitats. In addition, we designed specific primers to explore the diversity and environmental distribution of bacteria in the TG-1 phylum.

scholarly journals Denitratisoma oestradiolicum gen. nov., sp. nov., a 17β-oestradiol-degrading, denitrifying betaproteobacterium

2006 ◽  
Vol 56 (7) ◽  
pp. 1547-1552 ◽  
Author(s):  
Michael Fahrbach ◽  
Jan Kuever ◽  
Ruth Meinke ◽  
Peter Kämpfer ◽  
Juliane Hollender
Keyword(s):  
Phylogenetic Analysis ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Gene Sequence ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
16S Rrna Gene Sequence ◽  
Physiological Data ◽  
Rrna Gene ◽  
Rrna Gene Sequence

A Gram-negative, motile, denitrifying bacterium (strain AcBE2-1T) was isolated from activated sludge of a municipal wastewater treatment plant using 17β-oestradiol (E2) as sole source of carbon and energy. Cells were curved rods, 0.4–0.8×0.8–2.0 μm in size, non-fermentative, non-spore-forming, oxidase-positive and catalase-negative. E2 was oxidized completely to carbon dioxide and water by reduction of nitrate to a mixture of dinitrogen monoxide and dinitrogen, with the intermediate accumulation of nitrite. Electron recoveries were between 90 and 100 %, taking assimilated E2 into account. With nitrate as the electron acceptor, the bacterium also grew on fatty acids (C2 to C6), isobutyrate, crotonate, dl-lactate, pyruvate, fumarate and succinate. Phylogenetic analysis of its 16S rRNA gene sequence revealed that strain AcBE2-1T represents a separate line of descent within the family Rhodocyclaceae (Betaproteobacteria). The closest relatives are the cholesterol-degrading, denitrifying bacteria Sterolibacterium denitrificans DSM 13999T and strain 72Chol (=DSM 12783), with <93.9 % sequence similarity. The G+C content of the DNA was 61.4 mol%. Detection of a quinone system with ubiquinone Q-8 as the predominant compound and a fatty acid profile that included high concentrations of C16 : 1 ω7c/iso-C15 : 0 2-OH and C16 : 0, in addition to C18 : 1 ω7c and small amounts of C8 : 0 3-OH, supported the results of the phylogenetic analysis. On the basis of 16S rRNA gene sequence data in combination with chemotaxonomic and physiological data, strain AcBE2-1T (=DSM 16959T=JCM 12830T) is placed in a new genus Denitratisoma gen. nov. as the type strain of the type species Denitratisoma oestradiolicum gen. nov., sp. nov.

scholarly journals Description of Sphingobium fuliginis sp. nov., a phenanthrene-degrading bacterium from a fly ash dumping site, and reclassification of Sphingomonas cloacae as Sphingobium cloacae comb. nov.

2006 ◽  
Vol 56 (9) ◽  
pp. 2147-2152 ◽  
Author(s):  
Om Prakash ◽  
Rup Lal
Keyword(s):  
Phylogenetic Analysis ◽  
Fatty Acid ◽  
Fly Ash ◽  
16S Rrna ◽  
Dna Hybridization ◽  
Type Strain ◽  
Rrna Gene ◽  
16S Rrna Gene Sequences ◽  
Dumping Site ◽  
Degrading Bacterium

A phenanthrene-degrading bacterium, strain TKPT, was isolated from a fly ash dumping site of the thermal power plant in Panki, Kanpur, India, by an enrichment culture method using phenanthrene as the sole source of carbon and energy. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain belonged to the genus Sphingobium, as it showed highest sequence similarity to Sphingobium herbicidovorans DSM 11019T (97.3 %) and Sphingomonas cloacae JCM 10874T (96.5 %), compared with only 91–93 % similarity to members of other genera such as Sphingomonas sensu stricto, Novosphingobium, Sphingopyxis and Sphingosinicella. In DNA–DNA hybridization experiments with strains that were closely related phylogenetically and in terms of 16S rRNA gene sequences, i.e. Sphingobium herbicidovorans DSM 11019T and Sphingomonas cloacae JCM 10874T, strain TKPT showed less than 70 % relatedness. Strain TKPT contained sphingoglycolipids SGL-1 and SGL-2 and 18 : 1ω7c as the predominant fatty acid, with 16 : 0 as a minor component and 14 : 0 2-OH as the major 2-hydroxy fatty acid. Thus, phylogenetic analysis, DNA–DNA hybridization, fatty acid and polar lipid profiles and differences in physiological and morphological features from the most closely related members of the Sphingobium group showed that strain TKPT represents a distinct species of Sphingobium. The name Sphingobium fuliginis sp. nov. is proposed, with the type strain TKPT (=MTCC 7295T=CCM 7327T). Sphingomonas cloacae JCM 10874T formed a coherent cluster with members of Sphingobium, did not reduce nitrate to nitrite and had a fatty acid profile similar to those of Sphingobium species; hence Sphingomonas cloacae should be transferred to the genus Sphingobium as Sphingobium cloacae comb. nov., with the type strain JCM 10874T (=DSM 14926T).

scholarly journals Phylogenetic relationships within the family Halobacteriaceae inferred from rpoB′ gene and protein sequences

2007 ◽  
Vol 57 (10) ◽  
pp. 2289-2295 ◽  
Author(s):  
Madalin Enache ◽  
Takashi Itoh ◽  
Tadamasa Fukushima ◽  
Ron Usami ◽  
Lucia Dumitru ◽  
...  
Keyword(s):  
16S Rrna ◽  
Molecular Marker ◽  
16S Rrna Gene ◽  
Phylogenetic Trees ◽  
Protein Sequences ◽  
Rpob Gene ◽  
Rrna Gene ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
The Family

In order to clarify the current phylogeny of the haloarchaea, particularly the closely related genera that have been difficult to sort out using 16S rRNA gene sequences, the DNA-dependent RNA polymerase subunit B′ gene (rpoB′) was used as a complementary molecular marker. Partial sequences of the gene were determined from 16 strains of the family Halobacteriaceae. Comparisons of phylogenetic trees inferred from the gene and protein sequences as well as from corresponding 16S rRNA gene sequences suggested that species of the genera Natrialba, Natronococcus, Halobiforma, Natronobacterium, Natronorubrum, Natrinema/Haloterrigena and Natronolimnobius formed a monophyletic group in all trees. In the RpoB′ protein tree, the alkaliphilic species Natrialba chahannaoensis, Natrialba hulunbeirensis and Natrialba magadii formed a tight group, while the neutrophilic species Natrialba asiatica formed a separate group with species of the genera Natronorubrum and Natronolimnobius. Species of the genus Natronorubrum were split into two groups in both the rpoB′ gene and protein trees. The most important advantage of the use of the rpoB′ gene over the 16S rRNA gene is that sequences of the former are highly conserved amongst species of the family Halobacteriaceae. All sequences determined so far can be aligned unambiguously without any gaps. On the other hand, gaps are necessary at 49 positions in the inner part of the alignment of 16S rRNA gene sequences. The rpoB′ gene and protein sequences can be used as an excellent alternative molecular marker in phylogenetic analysis of the Halobacteriaceae.

scholarly journals Methanobacterium movens sp. nov. and Methanobacterium flexile sp. nov., isolated from lake sediment

2011 ◽  
Vol 61 (12) ◽  
pp. 2974-2978 ◽  
Author(s):  
Jinxing Zhu ◽  
Xiaoli Liu ◽  
Xiuzhu Dong
Keyword(s):  
Phylogenetic Analysis ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Type Strain ◽  
Qaidam Basin ◽  
Sequence Similarity ◽  
Single Cells ◽  
Rrna Gene ◽  
Qinghai Province ◽  
Gram Staining

Two mesophilic methanogenic strains, designated TS-2T and GHT, were isolated from sediments of Tuosu lake and Gahai lake, respectively, in the Qaidam basin, Qinghai province, China. Cells of both isolates were rods (about 0.3–0.5×2–5 µm) with blunt rounded ends and Gram-staining-positive. Strain TS-2T was motile with one or two polar flagella and used only H2/CO2 for growth and methanogenesis. Strain GHT was non-motile, used both H2/CO2 and formate and displayed a variable cell arrangement depending on the substrate: long chains when growing in formate (50 mM) or under high pressure H2 and single cells under low pressure H2. Phylogenetic analysis based on 16S rRNA gene sequences placed the two isolates in the genus Methanobacterium. Strain TS-2T was most closely related to Methanobacterium alcaliphilum NBRC 105226T (96 % 16S rRNA gene sequence similarity). Phylogenetic analysis based on the alpha subunit of methyl-coenzyme M reductase also supported the affiliation of the two isolates with the genus Methanobacterium. DNA–DNA relatedness between the isolates and M. alcaliphilum DSM 3387T was 39–53 %. Hence we propose two novel species, Methanobacterium movens sp. nov. (type strain TS-2T = AS 1.5093T = JCM 15415T) and Methanobacterium flexile sp. nov. (type strain GHT = AS 1.5092T = JCM 15416T).

Sign in / Sign up

Export Citation Format

Share Document