Photorhabdus luminescens subsp. noenieputensis subsp. nov., a symbiotic bacterium associated with a novel Heterorhabditis species related to Heterorhabditis indica

2013 ◽  
Vol 63 (Pt_5) ◽  
pp. 1853-1858 ◽  
Author(s):  
Tiarin Ferreira ◽  
Carol van Reenen ◽  
Sylvie Pagès ◽  
Patrick Tailliez ◽  
Antoinette P. Malan ◽  
...  
Keyword(s):  
Type Species ◽  
Galleria Mellonella ◽  
Entomopathogenic Nematode ◽  
Symbiotic Bacterium ◽  
Tween 20 ◽  
Haemolytic Activity ◽  
Phenotypic Traits ◽  
Photorhabdus Luminescens ◽  
Content Type ◽  
Link Type

The bacterial symbiont AM7T, isolated from a novel entomopathogenic nematode species of the genus Heterorhabditis, displays the main phenotypic traits of the genus Photorhabdus and is highly pathogenic to Galleria mellonella. Phylogenetic analysis based on a multigene approach (16S rRNA, recA, gyrB, dnaN, gltX and infB) confirmed the classification of isolate AM7T within the species Photorhabdus luminescens and revealed its close relatedness to Photorhabdus luminescens subsp. caribbeanensis , P. luminescens subsp. akhurstii and P. luminescens subsp. hainanensis . The five concatenated protein-encoding sequences (4197 nt) of strain AM7T revealed 95.8, 95.4 and 94.9 % nucleotide identity to sequences of P. luminescens subsp. caribbeanensis HG29T, P. luminescens subsp. akhurstii FRG04T and P. luminescens subsp. hainanensis C8404T, respectively. These identity values are less than the threshold of 97 % proposed for classification within one of the existing subspecies of P. luminescens . Unlike other strains described for P. luminescens , strain AM7T produces acid from adonitol, sorbitol and xylitol, assimilates xylitol and has no lipase activity on medium containing Tween 20 or 60. Strain AM7T is differentiated from P. luminescens subsp. caribbeanensis by the assimilation of N-acetylglucosamine and the absence of haemolytic activity. Unlike P. luminescens subsp. akhurstii , strain AM7T does not assimilate mannitol, and it is distinguished from P. luminescens subsp. hainanensis by the assimilation of trehalose and citrate, the inability to produce indole from tryptophan and the presence of acetoin production and urease activity. Strain AM7T ( = ATCC BAA-2407T  = DSM 25462T) belongs to a novel subspecies, and is proposed as the type strain of Photorhabdus luminescens subsp. noenieputensis sp. nov.

Xenorhabdus lircayensis sp. nov., the symbiotic bacterium associated with the entomopathogenic nematode Steinernema unicornum

2021 ◽  
Vol 71 (12) ◽  
Author(s):  
Carlos Castaneda-Alvarez ◽  
Simona Prodan ◽  
Alan Zamorano ◽  
Ernesto San-Blas ◽  
Erwin Aballay
Keyword(s):  
New Species ◽  
Type Species ◽  
Entomopathogenic Nematode ◽  
Phylogenetic Reconstruction ◽  
Symbiotic Bacterium ◽  
Rrna Gene ◽  
Species List ◽  
Content Type ◽  
Link Type ◽  
Bacterium Strain

Xenorhabdus is a symbiotic group of bacteria associated with entomopathogenic nematodes of the family Steinernematidae. Although the described Steirnernema species list is extensive, not all their symbiotic bacteria have been identified. One single motile, Gram-negative and non-spore-forming rod-shaped symbiotic bacterium, strain VLST, was isolated from the entomopathogenic nematode Steinernema unicornum. Analyses of the 16S rRNA gene determined that the VLST isolate belongs to the genus Xenorhabdus , and its closest related species is Xenorhabdus szentirmaii DSM 16338T (98.2 %). Deeper analyses using the whole genome for phylogenetic reconstruction indicate that VLST exhibits a unique clade in the genus. Genomic comparisons considering digital DNA–DNA hybridization (dDDH) values confirms this result, showing that the VLST values are distant enough from the 70 % threshold suggested for new species, sharing 30.7, 30.5 and 30.3 % dDDH with Xenorhabdus khoisanae MCB, Xenorhabdus koppenhoeferi DSM 18168T and Xenorhabdus miraniensis DSM 18168T, respectively, as the closest species. Detailed physiological, biochemical and chemotaxonomic tests of the VLST isolate reveal consistent differences from previously described Xenorhabdus species. Phylogenetic, physiological, biochemical and chemotaxonomic approaches show that VLST represents a new species of the genus Xenorhabdus , for which the name Xenorhabdus lircayensis sp. nov. (type strain VLST=CCCT 20.04T=DSM 111583T) is proposed.

Description of Xenorhabdus magdalenensis sp. nov., the symbiotic bacterium associated with Steinernema australe

2012 ◽  
Vol 62 (Pt_8) ◽  
pp. 1761-1765 ◽  
Author(s):  
Patrick Tailliez ◽  
Sylvie Pagès ◽  
Steve Edgington ◽  
Lukasz M. Tymo ◽  
Alan G. Buddie
Keyword(s):  
Type Species ◽  
Sequence Similarity ◽  
Symbiotic Bacterium ◽  
Phylogenetic Position ◽  
Phenotypic Traits ◽  
Rrna Gene ◽  
Content Type ◽  
Link Type ◽  
Bacterium Strain ◽  
The Difference

A symbiotic bacterium, strain IMI 397775T, was isolated from the insect-pathogenic nematode Steinernema australe. On the basis of 16S rRNA gene sequence similarity, this bacterial isolate was shown to belong to the genus Xenorhabdus , in agreement with the genus of its nematode host. The accurate phylogenetic position of this new isolate was defined using a multigene approach and showed that isolate IMI 397775T shares a common ancestor with Xenorhabdus doucetiae FRM16T and Xenorhabdus romanii PR06-AT, the symbiotic bacteria associated with Steinernema diaprepesi and Steinernema puertoricense, respectively. The nucleotide identity (less than 97 %) between isolate IMI 397775T, X. doucetiae FRM16T and X. romanii PR06-AT calculated for the concatenated sequences of five gene fragments encompassing 4275 nt, several phenotypic traits and the difference between the upper temperatures that limit growth of these three bacteria allowed genetic and phenotypic differentiation of isolate IMI 397775T from the two closely related species. Strain IMI 397775T therefore represents a novel species, for which the name Xenorhabdus magdalenensis sp. nov. is proposed, with the type strain IMI 397775T ( = DSM 24915T).

Xenorhabdus ishibashii sp. nov., isolated from the entomopathogenic nematode Steinernema aciari

2013 ◽  
Vol 63 (Pt_5) ◽  
pp. 1690-1695 ◽  
Author(s):  
Ryusei Kuwata ◽  
Li-hong Qiu ◽  
Wen Wang ◽  
Yuki Harada ◽  
Mutsuhiro Yoshida ◽  
...  
Keyword(s):  
Type Species ◽  
Entomopathogenic Nematode ◽  
Sequence Similarity ◽  
Phenotypic Traits ◽  
Rrna Gene ◽  
Protein Coding ◽  
Content Type ◽  
Link Type ◽  
Mutualistic Association ◽  
Reference Strains

Gram-negative bacteria of the genus Xenorhabdus exhibit a mutualistic association with steinernematid entomopathogenic nematodes and a pathogenic relationship with insects. Here we describe two isolates of the entomopathogenic nematode Steinernema aciari collected from China and Japan. 16S rRNA gene sequence similarity and phylogenetic analysis indicated that the isolates obtained from S. aciari belonged to the genus Xenorhabdus . Multilocus sequence analysis based on five universal protein-coding gene sequences revealed that the isolates were closely related to Xenorhabdus ehlersii DSM 16337T and Xenorhabdus griffiniae ID10T but that they exhibited <97 % sequence similarity with these reference strains, which indicated that the isolates were distinct from previously described species. Based on these genetic differences and several differential phenotypic traits, we propose that the isolates represent a novel species of the genus Xenorhabdus , for which we propose the name Xenorhabdus ishibashii sp. nov. The type strain is GDh7T ( = DSM 22670T  = CGMCC 1.9166T).

scholarly journals Mutations in the two component regulator systems PmrAB and PhoPQ give rise to increased colistin resistance in Citrobacter and Enterobacter spp.

2020 ◽  
Vol 69 (4) ◽  
pp. 521-529 ◽  
Author(s):  
Matthew E. Wand ◽  
J. Mark Sutton
Keyword(s):  
Growth Rate ◽  
Type Species ◽  
Galleria Mellonella ◽  
Strain Differences ◽  
Fold Increase ◽  
Colistin Resistance ◽  
Content Type ◽  
Link Type ◽  
Carbapenem Resistant ◽  
Individual Strain

Introduction. Colistin is a last resort antibiotic for treating infections caused by carbapenem-resistant isolates. Mechanisms of resistance to colistin have been widely described in Klebsiella pneumoniae and Escherichia coli but have yet to be characterized in Citrobacter and Enterobacter species. Aim. To identify the causative mutations leading to generation of colistin resistance in Citrobacter and Enterobacter spp. Methodology. Colistin resistance was generated by culturing in increasing concentrations of colistin or by direct culture in a lethal (above MIC) concentration. Whole-genome sequencing was used to identify mutations. Fitness of resistant strains was determined by changes in growth rate, and virulence in Galleria mellonella. Results. We were able to generate colistin resistance upon exposure to sub-MIC levels of colistin, in several but not all strains of Citrobacter and Enterobacter resulting in a 16-fold increase in colistin MIC values for both species. The same individual strains also developed resistance to colistin after a single exposure at 10× MIC, with a similar increase in MIC. Genetic analysis revealed that this increased resistance was attributed to mutations in PmrB for Citrobacter and PhoP in Enterobacter , although we were not able to identify causative mutations in all strains. Colistin-resistant mutants showed little difference in growth rate, and virulence in G. mellonella, although there were strain-to-strain differences. Conclusions. Stable colistin resistance may be acquired with no loss of fitness in these species. However, only select strains were able to adapt suggesting that acquisition of colistin resistance is dependent upon individual strain characteristics.

Pseudoalteromonas ostreae sp. nov., a new bacterial species harboured by the flat oyster Ostrea edulis

2021 ◽  
Vol 71 (11) ◽  
Author(s):  
Héléna Cuny ◽  
Clément Offret ◽  
Amine M. Boukerb ◽  
Leila Parizadeh ◽  
Olivier Lesouhaitier ◽  
...  
Keyword(s):  
Type Species ◽  
Bacterial Species ◽  
Acid Methyl Ester ◽  
Phenotypic Traits ◽  
Rrna Gene ◽  
Ostrea Edulis ◽  
Content Type ◽  
Link Type ◽  
A Genome ◽  
Flat Oyster

Three bacterial strains, named hOe-66T, hOe-124 and hOe-125, were isolated from the haemolymph of different specimens of the flat oyster Ostrea edulis collected in Concarneau bay (Finistère, France). These strains were characterized by a polyphasic approach, including (i) whole genome analyses with 16S rRNA gene sequence alignment and pangenome analysis, determination of the G+C content, average nucleotide identity (ANI), and in silico DNA–DNA hybridization (isDDH), and (ii) fatty acid methyl ester and other phenotypic analyses. Strains hOe-66T, hOe-124 and hOe-125 were closely related to both type strains Pseudoalteromonas rhizosphaerae RA15T and Pseudoalteromonas neustonica PAMC 28425T with less than 93.3% ANI and 52.3% isDDH values. Regarding their phenotypic traits, the three strains were Gram-negative, 1–2 µm rod-shaped, aerobic, motile and non-spore-forming bacteria. Cells grew optimally at 25 °C in 2.5% NaCl and at 7–8 pH. The most abundant fatty acids were summed feature 3 (C16:1 ω7c/C16:1 ω6c), C16:0 and C17:1 ω8c. The strains carried a genome average size of 4.64 Mb and a G+C content of 40.28 mol%. The genetic and phenotypic results suggested that strains hOe-66T, hOe-124 and hOe-125 belong to a new species of the genus Pseudoalteromonas . In this context, we propose the name Pseudoalteromonas ostreae sp. nov. The type strain is hOe-66T (=CECT 30303T=CIP 111911T).

scholarly journals Pseudomonas granadensis sp. nov., a new bacterial species isolated from the Tejeda, Almijara and Alhama Natural Park, Granada, Spain

2015 ◽  
Vol 65 (Pt_2) ◽  
pp. 625-632 ◽  
Author(s):  
Javier Pascual ◽  
Marina García-López ◽  
Gerald F. Bills ◽  
Olga Genilloud
Keyword(s):  
Dna Hybridization ◽  
Type Species ◽  
Novel Species ◽  
Bacterial Species ◽  
Phenotypic Traits ◽  
Terminal Electron Acceptor ◽  
Content Type ◽  
Link Type ◽  
Natural Park ◽  
Fatty Acid Compositions

During the course of screening bacterial isolates as sources of as-yet unknown bioactive compounds with pharmaceutical applications, a chemo-organotrophic, Gram-negative bacterium was isolated from a soil sample taken from the Tejeda, Almijara and Alhama Natural Park, Granada, Spain. Strain F-278,770T was oxidase- and catalase-positive, aerobic, with a respiratory type of metabolism with oxygen as the terminal electron acceptor, non-spore-forming and motile by one polar flagellum, although some cells had two polar flagella. Phylogenetic analysis of the 16S rRNA, gyrB, rpoB and rpoD genes revealed that strain F-278,770T belongs to the Pseudomonas koreensis subgroup (Pseudomonas fluorescens lineage), with Pseudomonas moraviensis , P. koreensis , P. baetica and P. helmanticensis as its closest relatives. Chemotaxonomic traits such as polar lipid and fatty acid compositions and G+C content of genomic DNA corroborated the placement of strain F-278,770T in the genus Pseudomonas . DNA–DNA hybridization assays and phenotypic traits confirmed that this strain represents a novel species of the genus Pseudomonas , for which the name Pseudomonas granadensis sp. nov. is proposed. The type strain is F-278,770T ( = DSM 28040T = LMG 27940T).

scholarly journals Clavibacter michiganensis subsp. phaseoli subsp. nov., pathogenic in bean

2014 ◽  
Vol 64 (Pt_5) ◽  
pp. 1752-1755 ◽  
Author(s):  
Ana J. González ◽  
Estefanía Trapiello
Keyword(s):  
Type Species ◽  
Restriction Analysis ◽  
16S Rrna Gene Sequencing ◽  
Phenotypic Traits ◽  
Rrna Gene ◽  
Bacterial Disease ◽  
Clavibacter Michiganensis ◽  
Content Type ◽  
Link Type ◽  
Clavibacter Michiganensis Subsp

A yellow Gram-reaction-positive bacterium isolated from bean seeds (Phaseolus vulgaris L.) was identified as Clavibacter michiganensis by 16S rRNA gene sequencing. Molecular methods were employed in order to identify the subspecies. Such methods included the amplification of specific sequences by PCR, 16S amplified rDNA restriction analysis (ARDRA), RFLP and multilocus sequence analysis as well as the analysis of biochemical and phenotypic traits including API 50CH and API ZYM results. The results showed that strain LPPA 982T did not represent any known subspecies of C. michiganensis . Pathogenicity tests revealed that the strain is a bean pathogen causing a newly identified bacterial disease that we name bacterial bean leaf yellowing. On the basis of these results, strain LPPA 982T is regarded as representing a novel subspecies for which the name Clavibacter michiganensis subsp. phaseoli subsp. nov. is proposed. The type strain is LPPA 982T ( = CECT 8144T = LMG 27667T).

Oceanobacillus indicireducens sp. nov., a facultative alkaliphile that reduces an indigo dye

2013 ◽  
Vol 63 (Pt_4) ◽  
pp. 1437-1442 ◽  
Author(s):  
Kikue Hirota ◽  
Kenichi Aino ◽  
Yoshinobu Nodasaka ◽  
Isao Yumoto
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Type Strain ◽  
Type Species ◽  
Phylogenetic Analyses ◽  
Tween 20 ◽  
Rrna Gene ◽  
Content Type ◽  
Link Type ◽  
Content Similarity

An indigo-reducing facultatively alkaliphilic and halophilic strain, designated strain A21T, was isolated from a fermented Polygonum indigo (Polygonum tinctorium Lour.) liquor sample aged for 4 days prepared in a laboratory. 16S rRNA gene sequence phylogeny suggested that strain A21T was a member of the genus Oceanobacillus with the closest relative being the type strain of Oceanobacillus chironomi (similarity: 96.0 %). The cells of the isolate stained Gram-positive and were facultatively anaerobic straight rods that were motile by peritrichous flagella. The strain grew between 18 and 48 °C with optimum growth at 39 °C. It grew in the pH range of 7–12. It hydrolysed casein, gelatin and Tween 20 but not Tweens 40, 60 and 80, starch or DNA. No isoprenoid quinone was detected and the DNA G+C content was 39.7 mol%. The whole-cell fatty acid profile mainly consisted of iso-C15 : 0, anteiso-C15 : 0 and C16 : 0. DNA–DNA hybridization experiments with O. chironomi revealed 13 % relatedness. Owing to the differences in phenotypic and chemotaxonomic characteristics, and phylogenetic analyses based on 16S rRNA gene sequences and DNA–DNA relatedness data from reported Oceanobacillus species, the isolate merits classification as a representative of a novel species, for which the name Oceanobacillus indicireducens sp. nov. is proposed. The type strain is A21T ( = JCM 17251T  = NCIMB 14685T). The description of the genus Oceanobacillus is also emended.

scholarly journals Investigation of the polyamine biosynthetic and transport capability of Streptococcus agalactiae: the non-essential PotABCD transporter

Microbiology ◽  
2021 ◽  
Vol 167 (12) ◽  
Author(s):  
Sarah Khazaal ◽  
Rim Al Safadi ◽  
Dani Osman ◽  
Aurélia Hiron ◽  
Philippe Gilot
Keyword(s):  
Oxidative Stress ◽  
Streptococcus Agalactiae ◽  
Type Species ◽  
Physiological Stress ◽  
Acid Stress ◽  
Phenotypic Traits ◽  
Growth Media ◽  
Content Type ◽  
Peptidoglycan Biosynthesis ◽  
Link Type

Polyamines constitute a group of organic polycations positively charged at physiological pH. They are involved in a large variety of biological processes, including the protection against physiological stress. In this study, we show that the genome of Streptococcus agalactiae , a commensal bacterium of the intestine and the vagina and one of the most common agents responsible of neonate infections, does not encode proteins homologous to the specific enzymes involved in the known polyamine synthetic pathways. This lack of biosynthetic capability was verified experimentally by TLC analysis of the intracellular content of S. agalactiae grown in the absence of polyamines. However, similar analyses showed that the polyamines spermidine, spermine and putrescine can be imported from the growth media into the bacteria. We found that all strains of S. agalactiae possess the genes encoding the polyamine ABC transporter PotABCD. We demonstrated that these genes form an operon with folK, a gene involved in folate biosynthesis, murB, a gene involved in peptidoglycan biosynthesis, and with clc, a gene encoding a Cl−/H+ antiporter involved in resistance to acid stress in Escherichia coli . Transcription of the potABCD operon is induced by peroxide-induced oxidative stress but not by acidic stress. Spermidine and spermine were found to be inducers of potABCD transcription at pH 7.4 whereas putrescine induces this expression only during peroxide-induced oxidative stress. Using a deletion mutant of potABCD, we were nevertheless unable to associate phenotypic traits to the PotABCD transporter, probably due to the existence of one or more as yet identified transporters with a redundant action.

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