scholarly journals Genetic relatedness within the genus Campylobacter inferred from rpoB sequences

2006 ◽  
Vol 56 (5) ◽  
pp. 937-945 ◽  
Author(s):  
Bożena M. Korczak ◽  
Regina Stieber ◽  
Stefan Emler ◽  
André P. Burnens ◽  
Joachim Frey ◽  
...  

The genus Campylobacter comprises 17 species, some of which are important animal and human pathogens. To gain more insight into the genetic relatedness of this genus and to improve the molecular tools available for diagnosis, a universal sequencing approach was established for the gene encoding the beta-subunit of RNA polymerase (rpoB) for the genus Campylobacter. A total of 59 strains, including the type strains of currently recognized species as well as field isolates, were investigated in the study. A primer set specific for Campylobacter species enabled straightforward amplification and sequencing of a 530 bp fragment of the rpoB gene. The 16S rRNA gene sequences of all of the strains were determined in parallel. A good congruence was obtained between 16S rRNA and rpoB gene sequence-based trees within the genus Campylobacter. The branching of the rpoB tree was similar to that of the 16S rRNA gene tree, even though a few discrepancies were observed for certain species. The resolution of the rpoB gene within the genus Campylobacter was generally much higher than that of the 16S rRNA gene sequence, resulting in a clear separation of most species and even some subspecies. The universally applicable amplification and sequencing approach for partial rpoB gene sequence determination provides a powerful tool for DNA sequence-based discrimination of Campylobacter species.

2015 ◽  
Vol 65 (Pt_11) ◽  
pp. 3878-3884 ◽  
Author(s):  
Akira Nakamura

Strain 43PT was isolated as an l-glucose-utilizing bacterium from soil in Japan. Cells of the strain were Gram-stain-negative, aerobic and non-motile cocci. The 16S rRNA gene sequence of the strain showed high similarity to that of Paracoccus limosus (98.5 %). Phylogenetic analyses based on 16S rRNA gene sequences revealed that this strain belongs to the genus Paracoccus. Strain 43PT contained Q-10 as the sole isoprenoid quinone. The major cellular fatty acids were C18 : 1ω7c or C18 : 1ω6c and C16 : 0, and C18 : 0, C18 : 1ω9c, C10 : 0 3-OH and summed feature 2 were detected as minor components. The DNA G+C content of strain 43PT was 64.1 mol%. Strain 43PT contained the major polar lipids phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, an unknown aminolipid and two unknown glycolipids. The DNA–DNA relatedness between strain 43PT and the six related type strains of the genus Paracoccus, including P. limosus, was below 23 %. Based on the chemotaxonomic and physiological data and the values of DNA–DNA relatedness, especially the ability to assimilate l-glucose, this strain should be classified as a representative of a novel species of the genus Paracoccus, for which the name Paracoccus laeviglucosivorans sp. nov. (type strain 43PT = JCM 30587T = DSM 100094T) is proposed.


2007 ◽  
Vol 57 (11) ◽  
pp. 2485-2488 ◽  
Author(s):  
Jung-Hoon Yoon ◽  
So-Jung Kang ◽  
Hyun Woo Oh ◽  
Tae-Kwang Oh

A Gram-negative, non-motile, coccobacilli-shaped bacterium, DS-48T, was isolated from soil from Dokdo, Korea, and its taxonomic position was investigated by means of a polyphasic study. Strain DS-48T grew optimally at 25 °C and pH 7.0–8.0 in the presence of 0.5 % (w/v) NaCl. It contained Q-10 as the predominant ubiquinone and C18 : 1 ω7c and C18 : 1 2-OH as the major fatty acids. The DNA G+C content was 69.3 mol%. A phylogenetic analysis based on 16S rRNA gene sequences showed that strain DS-48T fell within the genus Roseomonas, clustering with Roseomonas lacus TH-G33T (at a bootstrap confidence level of 100 %). The levels of similarity between the 16S rRNA gene sequence of strain DS-48T and those of the type strains of recognized Roseomonas species were in the range 93.2–98.0 %. DNA–DNA relatedness data and differential phenotypic properties, together with the phylogenetic distinctiveness of DS-48T, revealed that this strain differs from recognized Roseomonas species. On the basis of phenotypic, phylogenetic and genetic data, therefore, strain DS-48T represents a novel species within the genus Roseomonas, for which the name Roseomonas terrae sp. nov. is proposed. The type strain is DS-48T (=KCTC 12874T=JCM 14592T).


2010 ◽  
Vol 60 (12) ◽  
pp. 2984-2990 ◽  
Author(s):  
Mitsuo Sakamoto ◽  
Natsuko Suzuki ◽  
Yoshimi Benno

hsp60 gene sequences were determined for members of the genus Bacteroides and sequence similarities were compared with those obtained for the 16S rRNA gene. Among the 29 Bacteroides type strains, the mean sequence similarity of the hsp60 gene (84.5 %) was significantly less than that of the 16S rRNA gene (90.7 %), indicating a high discriminatory power of the hsp60 gene. Species of the genus Bacteroides were differentiated well by hsp60 gene sequence analysis, except for Bacteroides pyogenes JCM 6294T, Bacteroides suis JCM 6292T and Bacteroides tectus JCM 10003T. The hsp60 gene sequence analysis and the levels of DNA–DNA relatedness observed demonstrated that these three type strains are a single species. Consequently, B. suis and B. tectus are heterotypic synonyms of B. pyogenes. This study suggests that the hsp60 gene is an alternative phylogenetic marker for the classification of species of the genus Bacteroides.


2005 ◽  
Vol 55 (3) ◽  
pp. 1097-1099 ◽  
Author(s):  
Stefan Spring ◽  
Peter Schumann ◽  
Cathrin Spröer

The 16S rRNA gene sequence of [Methanogenium] frittonii DSM 2832T was determined and was found to be 99·9 % similar to the sequence of Methanoculleus thermophilus DSM 2373T. DNA–DNA hybridizations between both strains revealed 86 % DNA–DNA binding, indicating that both strains belong to the same species. The determination of the DNA G+C content of both type strains, DSM 2832T and DSM 2373T, revealed values of 56·1 and 59·1 mol%, respectively. Based on the phenotypic and genotypic characteristics, it is proposed to unite the species [Methanogenium] frittonii and Methanoculleus thermophilus under the name Methanoculleus thermophilus, which is the earlier synonym and hence has priority. Emended descriptions of the species Methanoculleus thermophilus and the genus Methanogenium are also given.


2015 ◽  
Vol 65 (Pt_9) ◽  
pp. 2803-2809 ◽  
Author(s):  
Peter Kämpfer ◽  
Hans-Jürgen Busse ◽  
John A. McInroy ◽  
Jia Xu ◽  
Stefanie P. Glaeser

A yellow, nitrogen-fixing bacterial strain, NXU-44T, isolated from the rhizosphere of switchgrass (Panicum virgatum) in Auburn, Alabama, USA, was studied to determine its taxonomic position. Cells of the isolate were rod-shaped and Gram-stain-negative. A comparison of the 16S rRNA gene sequence with the sequences of the type strains of the most closely related species showed that the strain belongs to the genus Flavobacterium with highest sequence similarities to the type strains of Flavobacterium ginsenosidimutans (97.9 %), Flavobacterium phragmitis (97.6 %) and Flavobacterium anhuiense (97.5 %). The 16S rRNA gene sequence similarities to all other species of the genus Flavobacterium were below 97.5 %. The fatty acid profile of strain NXU-44T consisted of the major fatty acids iso-C15 : 0, iso-C15 : 0 2-OH/C16 : 1ω7c and iso-C17 : 0 3-OH. The major compounds in the polar lipid profile were phosphatidylethanolamine, phosphatidylserine, one aminolipid and two polar lipids. The quinone system was composed exclusively of menaquinone MK-6. The polyamine pattern contained the major compound sym-homospermidine and only minor amounts of other polyamines. The diagnostic diamino acid of the peptidoglycan was meso-diaminopimelic acid. These data and the differential biochemical and chemotaxonomic properties show that strain NXU-44T represents a novel species of the genus Flavobacterium for which the name Flavobacterium nitrogenifigens sp. nov. is proposed. The type strain is NXU-44T ( = LMG 28694T = CIP 110894T).


2018 ◽  
Author(s):  
R.A. Barco ◽  
G.M. Garrity ◽  
J.J. Scott ◽  
J.P. Amend ◽  
K.H. Nealson ◽  
...  

AbstractGenus assignment is fundamental in the characterization of microbes, yet there is currently no unambiguous way to demarcate genera solely using standard genomic relatedness indices. Here, we propose an approach to demarcate genera that relies on the combined use of the average nucleotide identity, genome alignment fraction, and the distinction between type species and non-type species. More than 750 genomes representing type strains of species from 10 different phyla, and 19 different taxonomic orders/families in Gram-positive/negative, bacterial and archaeal lineages were tested. Overall, all 19 analyzed taxa conserved significant genomic differences between members of a genus and type species of other genera in the same taxonomic family. Bacillus, Flavobacterium, Hydrogenovibrio, Lactococcus, Methanosarcina, Thiomicrorhabdus, Thiomicrospira, Shewanella, and Vibrio are discussed in detail. Less than 1% of the type strains analyzed need reclassification, highlighting that the adoption of the 16S rRNA gene as a taxonomic marker has provided consistency to the classification of microorganisms in recent decades. One exception to this is the genus Bacillus with 61% of type strains needing reclassification, including the human pathogens B. cereus and B. anthracis. The results provide a first line of evidence that the combination of genomic indices provides appropriate resolution to effectively demarcate genera within the current taxonomic framework that is based on the 16S rRNA gene. We also identify the emergence of natural breakpoints at the genome level that can further help in the circumscription of genera. Altogether, these results show that a distinct difference between distant relatives and close relatives at the genome level (i.e., genomic coherence) is an emergent property of genera in Bacteria and Archaea.


2007 ◽  
Vol 57 (2) ◽  
pp. 405-408 ◽  
Author(s):  
Fubin Qiu ◽  
Ying Huang ◽  
Lei Sun ◽  
Xiaoxia Zhang ◽  
Zhiheng Liu ◽  
...  

A Gram-positive, rod-shaped, non-motile bacterium, designated strain wged11T, was isolated from the root of ginseng, and its taxonomic position was established using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences showed that this organism formed a robust clade with recognized species of the genus Leifsonia. Strain wged11T was characterized by a high content of ω-cyclohexylundecanoic and anteiso- and iso-branched saturated fatty acids, MK-11 as the major menaquinone and dl-2,4-diaminobutyric acid in its cell-wall peptidoglycan. The DNA G+C content of strain wged11T was 66.4 mol%. Levels of similarity between the 16S rRNA gene sequence of strain wged11T and those of the type strains of other members of the genus Leifsonia ranged from 94.7 to 97.6 %. The mean level of DNA–DNA relatedness between strain wged11T and Leifsonia poae DSM 15202T, its nearest phylogenetic neighbour, was 35.3 %. Based on these findings, strain wged11T (=CGMCC 4.3491T=JCM 13908T) is proposed as the type strain of a novel species of the genus Leifsonia, Leifsonia ginsengi sp. nov.


2010 ◽  
Vol 60 (11) ◽  
pp. 2548-2551 ◽  
Author(s):  
Amanda L. Jones ◽  
Gail D. Payne ◽  
Michael Goodfellow

The taxonomic status of an actinomycete isolated from soil collected from a hay meadow was determined using a polyphasic approach. The strain, designated N1350T, had morphological and chemotaxonomic properties consistent with its classification in the genus Williamsia and formed a distinct phyletic line within the clade comprising the type strains of species of the genus Williamsia in the 16S rRNA gene tree. Strain N1350T shared highest 16S rRNA gene sequence similarities with Williamsia marianensis MT8T (98.1 %) and Williamsia muralis MA140-96T (98.3 %). However, strain N1350T was readily distinguished from the type strains of Williamsia species using a combination of phenotypic properties. On the basis of these data, strain N1350T is considered to represent a novel species of the genus Williamsia. The name proposed for this taxon is Williamsia faeni sp. nov., with the type strain N1350T (=DSM 45372T =NCIMB 14575T =NRRL B-24794T).


2015 ◽  
Vol 65 (Pt_7) ◽  
pp. 2179-2186 ◽  
Author(s):  
Peter Kämpfer ◽  
Hans-Jürgen Busse ◽  
John A. McInroy ◽  
Stefanie P. Glaeser

A yellow-pigmented bacterial strain, 91A-612T, isolated from the geocarposphere (soil around the peanut) of very immature peanuts (Arachis hypogaea) in Alabama, USA, was studied for its taxonomic position. Cells of the isolate were rod-shaped and stained Gram-negative. A comparison of the 16S rRNA gene sequence with the sequences of the type strains of the most closely related species showed that the strain belongs to the genus Chryseobacterium, showing the highest sequence similarities to the type strains of Chryseobacterium molle (98.4 %), C. pallidum (98.3 %) and C. hominis (97.8 %). The 16S rRNA gene sequence similarities to the type strains of all other species of the genus Chryseobacterium were below 97.0 %. The fatty acid profile of strain 91A-612T consisted of the major fatty acids iso-C15 : 0, summed feature 3 (iso-C15 : 0 2-OH/C16 : 1ω7c) and iso-C17 : 0 3-OH. Major compounds in the polar lipid profile were phosphatidylethanolamine and several unidentified lipids, including two lipids that did not contain a sugar moiety, an amino group or a phosphate group (L3, L8), and an aminolipid (AL1). The quinone system was composed mainly of MK-6. The polyamine pattern contained sym-homospermidine as the major compound and moderate amounts of spermidine and spermine. DNA–DNA hybridizations between strain 91A-612T and the type strains of C. molle, C. pallidum and C. hominis resulted in relatedness values well below 70 %. These data and the differentiating biochemical and chemotaxonomic properties showed that isolate 91A-612T represents a novel species of the genus Chryseobacterium, for which we propose the name Chryseobacterium arachidiradicis sp. nov. (type strain 91A-612T = LMG 27814T = CCM 8490T = CIP 110647T).


2007 ◽  
Vol 57 (8) ◽  
pp. 1721-1724 ◽  
Author(s):  
Myung Kyum Kim ◽  
Hee-Young Jung

A novel strain, designated KP01T, belonging to the class Sphingobacteria (phylum Bacteroidetes) was isolated from soil in South Korea and was characterized taxonomically using a polyphasic approach. The strain was found to comprise Gram-negative, aerobic, non-motile, non-spore-forming rods. A phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain belonged to the genus Chitinophaga but was clearly separated from established Chitinophaga species. The 16S rRNA gene sequence similarities between KP01T and type strains of established Chitinophaga species ranged from 90.3 to 95.7 %. Phenotypic and chemotaxonomic data (major menaquinone, MK-7; major fatty acids, iso-C15 : 0 and C16 : 1 ω5c; major hydroxy fatty acid, C17 : 0 iso 3-OH) supported the affiliation of strain KP01T with the genus Chitinophaga. Therefore strain KP01T represents a novel species, for which the name Chitinophaga terrae sp. nov. is proposed. The type strain is KP01T (=KCTC 12836T =LMG 24015T).


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