scholarly journals Differentiation of Bifidobacterium species using partial RNA polymerase β-subunit (rpoB) gene sequences

2010 ◽  
Vol 60 (12) ◽  
pp. 2697-2704 ◽  
Author(s):  
Byoung Jun Kim ◽  
Hee-Youn Kim ◽  
Yeo-Jun Yun ◽  
Bum-Joon Kim ◽  
Yoon-Hoh Kook

Partial RNA polymerase β-subunit gene (rpoB) sequences (315 bp) were determined and used to differentiate the type strains of 23 species of the genus Bifidobacterium. The sequences were compared with those of the partial hsp60 (604 bp) and 16S rRNA genes (1475 or 1495 bp). The rpoB gene sequences showed nucleotide sequence similarities ranging from 84.1 % to 99.0 %, while the similarities of the hsp60 sequences ranged from 78.5 % to 99.7 % and the 16S rRNA gene sequence similarities ranged from 89.4 % to 99.2 %. The phylogenetic trees constructed from the sequences of these three genes showed similar clustering patterns, with the exception of several species. The Bifidobacterium catenulatum–Bifidobacterium pseudocatenulatum, Bifidobacterium pseudolongum subsp. pseudolongum–Bifidobacterium pseudolongum subsp. globosum and Bifidobacterium gallinarum–Bifidobacterium pullorum–Bifidobacterium saeculare groups were more clearly differentiated in the partial rpoB and hsp60 gene sequence trees than they were in the 16S rRNA gene tree. Based on sequence similarities and tree topologies, the newly determined rpoB gene sequences are suitable molecular markers for the differentiation of species of the genus Bifidobacterium and support various other molecular tools used to determine the relationships among species of this genus.

2004 ◽  
Vol 54 (6) ◽  
pp. 2095-2105 ◽  
Author(s):  
Toïdi Adékambi ◽  
Michel Drancourt

The current classification of non-pigmented and late-pigmenting rapidly growing mycobacteria (RGM) capable of producing disease in humans and animals consists primarily of three groups, the Mycobacterium fortuitum group, the Mycobacterium chelonae–abscessus group and the Mycobacterium smegmatis group. Since 1995, eight emerging species have been tentatively assigned to these groups on the basis of their phenotypic characters and 16S rRNA gene sequence, resulting in confusing taxonomy. In order to assess further taxonomic relationships among RGM, complete sequences of the 16S rRNA gene (1483–1489 bp), rpoB (3486–3495 bp) and recA (1041–1056 bp) and partial sequences of hsp65 (420 bp) and sodA (441 bp) were determined in 19 species of RGM. Phylogenetic trees based upon each gene sequence, those based on the combined dataset of the five gene sequences and one based on the combined dataset of the rpoB and recA gene sequences were then compared using the neighbour-joining, maximum-parsimony and maximum-likelihood methods after using the incongruence length difference test. Combined datasets of the five gene sequences comprising nearly 7000 bp and of the rpoB+recA gene sequences comprising nearly 4600 bp distinguished six phylogenetic groups, the M. chelonae–abscessus group, the Mycobacterium mucogenicum group, the M. fortuitum group, the Mycobacterium mageritense group, the Mycobacterium wolinskyi group and the M. smegmatis group, respectively comprising four, three, eight, one, one and two species. The two protein-encoding genes rpoB and recA improved meaningfully the bootstrap values at the nodes of the different groups. The species M. mucogenicum, M. mageritense and M. wolinskyi formed new groups separated from the M. chelonae–abscessus, M. fortuitum and M. smegmatis groups, respectively. The M. mucogenicum group was well delineated, in contrast to the M. mageritense and M. wolinskyi groups. For phylogenetic organizations derived from the hsp65 and sodA gene sequences, the bootstrap values at the nodes of a few clusters were <70 %. In contrast, phylogenetic organizations obtained from the 16S rRNA, rpoB and recA genes were globally similar to that inferred from combined datasets, indicating that the rpoB and recA genes appeared to be useful tools in addition to the 16S rRNA gene for the investigation of evolutionary relationships among RGM species. Moreover, rpoB gene sequence analysis yielded bootstrap values higher than those observed with recA and 16S rRNA genes. Also, molecular signatures in the rpoB and 16S rRNA genes of the M. mucogenicum group showed that it was a sister group of the M. chelonae–abscessus group. In this group, M. mucogenicum ATCC 49650T was clearly distinguished from M. mucogenicum ATCC 49649 with regard to analysis of the five gene sequences. This was in agreement with phenotypic and biochemical characteristics and suggested that these strains are representatives of two closely related, albeit distinct species.


2007 ◽  
Vol 57 (11) ◽  
pp. 2720-2724 ◽  
Author(s):  
Donovan P. Kelly ◽  
Yoshihito Uchino ◽  
Harald Huber ◽  
Ricardo Amils ◽  
Ann P. Wood

The published sequence of the 16S rRNA gene of Thiomonas cuprina strain Hö5 (=DSM 5495T) (GenBank accession no. U67162) was found to be erroneous. The 16S rRNA genes from the type strain held by the DSMZ since 1990 (DSM 5495T =NBRC 102145T) and strain Hö5 maintained frozen in the Universität Regensburg for 23 years (=NBRC 102094) were sequenced and found to be identical, but to show no significant similarity to the U67162 sequence. This also casts some doubt on the previously published 5S and 23S rRNA gene sequences (GenBank accession nos U67171 and X75567). The correct 16S rRNA gene sequence showed 99.8 % identity to those from Thiomonas delicata NBRC 14566T and ‘Thiomonas arsenivorans’ DSM 16361. The properties of these three species are re-evaluated, and emended descriptions are provided for the genus Thiomonas and the species Thiomonas cuprina.


2005 ◽  
Vol 71 (12) ◽  
pp. 8301-8304 ◽  
Author(s):  
Amy Beumer ◽  
Jayne B. Robinson

ABSTRACT Genomic analysis has revealed heterogeneity among bacterial 16S rRNA gene sequences within a single species; yet the cause(s) remains uncertain. Generalized transducing bacteriophages have recently gained recognition for their abundance as well as their ability to affect lateral gene transfer and to harbor bacterial 16S rRNA gene sequences. Here, we demonstrate the ability of broad-host-range, generalized transducing phages to acquire 16S rRNA genes and gene sequences. Using PCR and primers specific to conserved regions of the 16S rRNA gene, we have found that generalized transducing phages (D3112, UT1, and SN-T), but not specialized transducing phages (D3), acquired entire bacterial 16S rRNA genes. Furthermore, we show that the broad-host-range, generalized transducing phage SN-T is capable of acquiring the 16S rRNA gene from two different genera: Sphaerotilus natans, the host from which SN-T was originally isolated, and Pseudomonas aeruginosa. In sequential infections, SN-T harbored only 16S rRNA gene sequences of the final host as determined by restriction fragment length polymorphism analysis. The frequency of 16S rRNA gene sequences in SN-T populations was determined to be 1 × 10−9 transductants/PFU. Our findings further implicate transduction in the horizontal transfer of 16S rRNA genes between different species or genera of bacteria.


2005 ◽  
Vol 71 (10) ◽  
pp. 6308-6318 ◽  
Author(s):  
Helen A. Vrionis ◽  
Robert T. Anderson ◽  
Irene Ortiz-Bernad ◽  
Kathleen R. O'Neill ◽  
Charles T. Resch ◽  
...  

ABSTRACT The geochemistry and microbiology of a uranium-contaminated subsurface environment that had undergone two seasons of acetate addition to stimulate microbial U(VI) reduction was examined. There were distinct horizontal and vertical geochemical gradients that could be attributed in large part to the manner in which acetate was distributed in the aquifer, with more reduction of Fe(III) and sulfate occurring at greater depths and closer to the point of acetate injection. Clone libraries of 16S rRNA genes derived from sediments and groundwater indicated an enrichment of sulfate-reducing bacteria in the order Desulfobacterales in sediment and groundwater samples. These samples were collected nearest the injection gallery where microbially reducible Fe(III) oxides were highly depleted, groundwater sulfate concentrations were low, and increases in acid volatile sulfide were observed in the sediment. Further down-gradient, metal-reducing conditions were present as indicated by intermediate Fe(II)/Fe(total) ratios, lower acid volatile sulfide values, and increased abundance of 16S rRNA gene sequences belonging to the dissimilatory Fe(III)- and U(VI)-reducing family Geobacteraceae. Maximal Fe(III) and U(VI) reduction correlated with maximal recovery of Geobacteraceae 16S rRNA gene sequences in both groundwater and sediment; however, the sites at which these maxima occurred were spatially separated within the aquifer. The substantial microbial and geochemical heterogeneity at this site demonstrates that attempts should be made to deliver acetate in a more uniform manner and that closely spaced sampling intervals, horizontally and vertically, in both sediment and groundwater are necessary in order to obtain a more in-depth understanding of microbial processes and the relative contribution of attached and planktonic populations to in situ uranium bioremediation.


2004 ◽  
Vol 54 (4) ◽  
pp. 1349-1353 ◽  
Author(s):  
Chuji Hiruki ◽  
Keri Wang

Clover proliferation phytoplasma (CPR) is designated as the reference strain for the CP phylogenetic group or subclade, on the basis of molecular analyses of genomic DNA, the 16S rRNA gene and the 16S–23S spacer region. Other strains related to CPR include alfalfa witches'-broom (AWB), brinjal little leaf (BLL), beet leafhopper-transmitted virescence (BLTV), Illinois elm yellows (ILEY), potato witches'-broom (PWB), potato yellows (PY), tomato big bud in California (TBBc) and phytoplasmas from Fragaria multicipita (FM). Phylogenetic analysis of the 16S rRNA gene sequences of BLL, CPR, FM and ILEY, together with sequences from 16 other phytoplasmas that belong to the ash yellows (AshY), jujube witches'-broom (JWB) and elm yellows (EY) groups that were available in GenBank, produced a tree on which these phytoplasmas clearly clustered as a discrete group. Three subgroups have been classified on the basis of sequence homology and the collective RFLP patterns of amplified 16S rRNA genes. AWB, BLTV, PWB and TBBc are assigned to taxonomic subgroup CP-A, FM belongs to subgroup CP-B and BLL and ILEY are assigned to subgroup CP-C. Genetic heterogeneity between different isolates of AWB, CPR and PWB has been observed from heteroduplex mobility assay analysis of amplified 16S rRNA genes and the 16S–23S spacer region. Two unique signature sequences that can be utilized to distinguish the CP group from others were present. On the basis of unique properties of the DNA from clover proliferation phytoplasma, the name ‘Candidatus Phytoplasma trifolii’ is proposed for the CP group.


2006 ◽  
Vol 55 (1) ◽  
pp. 109-113 ◽  
Author(s):  
Ali Al-Ahmad ◽  
Thorsten Mathias Auschill ◽  
Gabriele Braun ◽  
Elmar Hellwig ◽  
Nicole Birgit Arweiler

This study was carried out in order to compare two PCR-based methods in the detection of Streptococcus mutans. The first PCR method was based on primers for the 16S rRNA gene and the second method was based on specific primers that targeted the glucosyltransferase gene (gtfB). Each PCR was performed with eight different streptococci from the viridans group, five other streptococci and 17 different non-streptococcal bacterial strains. Direct use of the S. mutans 16S rRNA gene-specific primers revealed that Streptococcus gordonii and Streptococcus infantis were also detected. After amplifying the 16S rRNA gene with universal primers and subsequently performing nested PCR, the S. mutans-specific nested primers based on the 16S rRNA gene detected all tested streptococci. There was no cross-reaction of the gtfB primers after direct PCR. Our results indicate that direct PCR and nested PCR based on 16S rRNA genes can reveal false-positive results for oral streptococci and lead to an overestimation of the prevalence of S. mutans with regards to its role as the most prevalent causative agent of dental caries.


2012 ◽  
Vol 62 (Pt_3) ◽  
pp. 632-637 ◽  
Author(s):  
Song-Ih Han ◽  
Hyo-Jin Lee ◽  
Hae-Ran Lee ◽  
Ki-Kwang Kim ◽  
Kyung-Sook Whang

Three exopolysaccharide-producing bacteria, designated strains DRP28T, DRP29 and DRP31, were isolated from the rhizoplane of Angelica sinensis from the Geumsan, Republic of Korea. Cells were straight rods, Gram reaction-negative, aerobic, non-motile, and catalase- and oxidase- positive. Flexirubin-type pigments were absent. Phylogenetic analysis of the 16S rRNA gene indicated that these bacteria belong to the genus Mucilaginibacter in the phylum Bacteroidetes. 16S rRNA gene sequence similarities to strains of recognized species of the genus Mucilaginibacter were 93.8–97.4 %. The major fatty acids were iso-C15 : 0 and summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH). The strains contained MK-7 as the major isoprenoid quinone. Strains DRP28T, DRP29 and DRP31 formed a single, distinct genomospecies with DNA G+C contents of 41.9–42.7 mol% and DNA hybridization values of 82.6–86.8 %; the strains exhibited DNA–DNA hybridization values of only 20.4–41.3 % with related species of the genus Mucilaginibacter. On the basis of evidence presented in this study, strains DRP28T, DRP29 and DRP31 were considered to represent a novel species of the genus Mucilaginibacter, for which the name Mucilaginibacter polysacchareus sp. nov. is proposed. The type strain is DRP28T ( = KACC 15075T  = NBRC 107757T).


2010 ◽  
Vol 60 (11) ◽  
pp. 2552-2556 ◽  
Author(s):  
Ping Fa Zhou ◽  
Wei Min Chen ◽  
Ge Hong Wei

Previously, five rhizobial strains isolated from root nodules of Robinia pseudoacacia were assigned to the same genospecies on the basis of identical 16S rRNA gene sequences and phylogenetic analyses of the nodA, nodC and nifH genes, in which the five isolates formed a well-supported group that excluded other sequences found in public databases. In this study, the 16S rRNA gene sequence similarities between the isolates and Mesorhizobium mediterraneum UPM-Ca36T and Mesorhizobium temperatum SDW018T were 99.5 and 99.6 %, respectively. The five isolates were also different from defined Mesorhizobium species using ERIC fingerprint profiles and they formed a novel Mesorhizobium lineage in phylogenetic analyses of recA and atpD gene sequences. DNA–DNA relatedness values between the representative strain, CCNWYC 115T, and type strains of defined Mesorhizobium species were found to be lower than 47.5 %. These results indicated that the isolates represented a novel genomic species. Therefore, a novel species, Mesorhizobium robiniae sp. nov., is proposed, with type strain CCNWYC 115T (=ACCC 14543T =HAMBI 3082T). Strain CCNWYC 115T can form effective nodules only on its original host.


2021 ◽  
Author(s):  
Antti Juhani Rissanen ◽  
Moritz Buck ◽  
Sari Peura

A putative novel methanotrophic genus, Candidatus Methylumidiphilus (Methylococcales), was recently shown to be ubiquitous and one of the most abundant methanotrophic genera in water columns of oxygen-stratified lakes and ponds of boreal and subarctic area. However, it has probably escaped detection in many previous studies using 16S rRNA gene amplicon sequencing due to insufficient database coverage, which is because Ca. Methylumidiphilus lacks cultured representatives and previously analysed metagenome assembled genomes (MAGs) affiliated with it do not contain 16S rRNA genes. Therefore, we screened MAGs affiliated with the genus for their 16S rRNA gene sequences in a recently published lake and pond MAG dataset. Among 66 MAGs classified as Ca. Methylumidiphilus (with completeness over 40% and contamination less than 5%) originating from lakes in Finland, Sweden and Switzerland as well as from ponds in Canada, we could find 5 MAGs each containing one 1532 bp long sequence spanning the V1-V9 regions of the 16S rRNA gene. After removal of sequence redundancy, this resulted in two unique 16S rRNA gene sequences. These sequences represented two different putative species, i.e. Ca. Methylumidiphilus alinenensis (Genbank accession: OK236221) as well as another so far unnamed species of Ca. Methylumidiphilus (Genbank accession: OK236220). We suggest that including these two sequences in reference databases will enhance 16S rRNA gene - based detection of members of this genus from environmental samples.


2005 ◽  
Vol 55 (5) ◽  
pp. 1857-1862 ◽  
Author(s):  
Diva do Carmo Teixeira ◽  
Colette Saillard ◽  
Sandrine Eveillard ◽  
Jean Luc Danet ◽  
Paulo Inácio da Costa ◽  
...  

Symptoms of huanglongbing (HLB) were reported in São Paulo State (SPS), Brazil, in March 2004. In Asia, HLB is caused by ‘Candidatus Liberibacter asiaticus' and in Africa by ‘Candidatus Liberibacter africanus’. Detection of the liberibacters is based on PCR amplification of their 16S rRNA gene with specific primers. Leaves with blotchy mottle symptoms characteristic of HLB were sampled in several farms of SPS and tested for the presence of liberibacters. ‘Ca. L. asiaticus' was detected in a small number of samples but most samples gave negative PCR results. Therefore, a new HLB pathogen was suspected. Evidence for an SPS-HLB bacterium in symptomatic leaves was obtained by PCR amplification with universal primers for prokaryotic 16S rRNA gene sequences. The amplified 16S rRNA gene was cloned and sequenced. Sequence analysis and phylogeny studies showed that the 16S rRNA gene possessed the oligonucleotide signatures and the secondary loop structure characteristic of the α-Proteobacteria, including the liberibacters. The 16S rRNA gene sequence phylogenetic tree showed that the SPS-HLB bacterium clustered within the α-Proteobacteria, the liberibacters being its closest relatives. For these reasons, the SPS-HLB bacterium is considered a member of the genus ‘Ca. Liberibacter’. However, while the 16S rRNA gene sequences of ‘Ca. L. asiaticus' and ‘Ca. L. africanus' had 98·4 % similarity, the 16S rRNA gene sequence of the SPS-HLB liberibacter had only 96·0 % similarity with the 16S rRNA gene sequences of ‘Ca. L. asiaticus' or ‘Ca. L. africanus’. This lower similarity was reflected in the phylogenetic tree, where the SPS-HLB liberibacter did not cluster within the ‘Ca. L asiaticus’/‘Ca. L. africanus group’, but as a separate branch. Within the genus ‘Candidatus Liberibacter’ and for a given species, the 16S/23S intergenic region does not vary greatly. The intergenic regions of three strains of ‘Ca. L. asiaticus’, from India, the People's Republic of China and Japan, were found to have identical or almost identical sequences. In contrast, the intergenic regions of the SPS-HLB liberibacter, ‘Ca. L. asiaticus' and ‘Ca. L. africanus' had quite different sequences, with similarity between 66·0 and 79·5 %. These results confirm that the SPS-HLB liberibacter is a novel species for which the name ‘Candidatus Liberibacter americanus' is proposed. Like the African and the Asian liberibacters, the ‘American’ liberibacter is restricted to the sieve tubes of the citrus host. The liberibacter could also be detected by PCR amplification of the 16S rRNA gene in Diaphorina citri, the psyllid vector of ‘Ca. L. asiaticus’, suggesting that this psyllid is also a vector of ‘Ca. L. americanus' in SPS. ‘Ca. L. americanus' was detected in 216 of 218 symptomatic leaf samples from 47 farms in 35 municipalities, while ‘Ca. L. asiaticus' was detected in only 4 of the 218 samples, indicating that ‘Ca. L. americanus' is the major cause of HLB in SPS.


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