scholarly journals Comparative genomics of the Pseudomonas corrugata subgroup reveals high species diversity and allows the description of Pseudomonas ogarae sp. nov.

2021 ◽  
Vol 7 (6) ◽  
Author(s):  
Daniel Garrido-Sanz ◽  
Miguel Redondo-Nieto ◽  
Marta Martin ◽  
Rafael Rivilla

Pseudomonas corrugata constitute one of the phylogenomic subgroups within the Pseudomonas fluorescens species complex and include both plant growth-promoting rhizobacteria (PGPR) and plant pathogenic bacteria. Previous studies suggest that the species diversity of this group remains largely unexplored together with frequent misclassification of strains. Using more than 1800 sequenced Pseudomonas genomes we identified 121 genomes belonging to the P. corrugata subgroup. Intergenomic distances obtained using the genome-to-genome blast distance (GBDP) algorithm and the determination of digital DNA–DNA hybridization values were further used for phylogenomic and clustering analyses, which revealed 29 putative species clusters, of which only five correspond to currently named species within the subgroup. Comparative and functional genome-scale analyses also support the species status of these clusters. The search for PGPR and plant pathogenic determinants showed that approximately half of the genomes analysed could have a pathogenic behaviour based on the presence of a pathogenicity genetic island, while all analysed genomes possess PGPR traits. Finally, this information together with the characterization of phenotypic traits, allows the reclassification proposal of Pseudomonas fluorescens F113 as Pseudomonas ogarae sp. nov., nom rev., type strain F113T (=DSM 112162T=CECT 30235T), which is substantiated by genomic, functional genomics and phenotypic differences with their closest type strains.


2013 ◽  
Vol 63 (Pt_12) ◽  
pp. 4386-4395 ◽  
Author(s):  
Maria del Carmen Montero-Calasanz ◽  
Markus Göker ◽  
Manfred Rohde ◽  
Cathrin Spröer ◽  
Peter Schumann ◽  
...  

A novel non-motile, Gram-staining-negative, yellow-pigmented bacterium, designated AG13T, isolated from a rain water pond at a plant nursery in Spain and characterized as a plant-growth-promoting bacterium, was investigated to determine its taxonomic status. The isolate grew best over a temperature range of 15–40 °C, at pH 5.0–8.0 and with 0–4 % (w/v) NaCl. Chemotaxonomic and molecular characteristics of the isolate matched those described for members of the genus Chryseobacterium . The DNA G+C content of the novel strain was 37.2 mol%. The strain had a polyamine pattern with sym-homospermidine as the major compound and produced flexirubin-type pigments. MK-6 was the dominant menaquinone and the major cellular fatty acids were iso-C15 : 0, C17 : 1ω9c and iso-C17 : 0 3-OH. The main polar lipids were phosphatidylethanolamine, aminolipids and several unidentified lipids. The 16S rRNA gene showed 92.0–97.2 % sequence similarity with those of the members of the genus Chryseobacterium . Based on chemotaxonomic and phenotypic traits, and DNA–DNA hybridizations with the type strains of the most closely related species, the isolate is proposed to represent a novel species, Chryseobacterium hispalense, type strain AG13T ( = DSM 25574T = CCUG 63019T). Emended descriptions of the species Chryseobacterium defluvii , Chryseobacterium indologenes , Chryseobacterium wanjuense and Chryseobacterium gregarium are also provided.



Microbiology ◽  
2021 ◽  
Vol 167 (10) ◽  
Author(s):  
James P. R. Connolly ◽  
Natasha C. A. Turner ◽  
Jennifer C. Hallam ◽  
Patricia T. Rimbi ◽  
Tom Flett ◽  
...  

Appropriate interpretation of environmental signals facilitates niche specificity in pathogenic bacteria. However, the responses of niche-specific pathogens to common host signals are poorly understood. d-Serine (d-ser) is a toxic metabolite present in highly variable concentrations at different colonization sites within the human host that we previously found is capable of inducing changes in gene expression. In this study, we made the striking observation that the global transcriptional response of three Escherichia coli pathotypes – enterohaemorrhagic E. coli (EHEC), uropathogenic E. coli (UPEC) and neonatal meningitis-associated E. coli (NMEC) – to d-ser was highly distinct. In fact, we identified no single differentially expressed gene common to all three strains. We observed the induction of ribosome-associated genes in extraintestinal pathogens UPEC and NMEC only, and the induction of purine metabolism genes in gut-restricted EHEC, and UPEC indicating distinct transcriptional responses to a common signal. UPEC and NMEC encode dsdCXA – a genetic locus required for detoxification and hence normal growth in the presence of d-ser. Specific transcriptional responses were induced in strains accumulating d-ser (WT EHEC and UPEC/NMEC mutants lacking the d-ser-responsive transcriptional activator DsdC), corroborating the notion that d-ser is an unfavourable metabolite if not metabolized. Importantly, many of the UPEC-associated transcriptome alterations correlate with published data on the urinary transcriptome, supporting the hypothesis that d-ser sensing forms a key part of urinary niche adaptation in this pathotype. Collectively, our results demonstrate distinct pleiotropic responses to a common metabolite in diverse E. coli pathotypes, with important implications for niche selectivity.



Author(s):  
Héléna Cuny ◽  
Clément Offret ◽  
Amine M. Boukerb ◽  
Leila Parizadeh ◽  
Olivier Lesouhaitier ◽  
...  

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).



2015 ◽  
Vol 65 (Pt_2) ◽  
pp. 625-632 ◽  
Author(s):  
Javier Pascual ◽  
Marina García-López ◽  
Gerald F. Bills ◽  
Olga Genilloud

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).



2014 ◽  
Vol 64 (Pt_5) ◽  
pp. 1752-1755 ◽  
Author(s):  
Ana J. González ◽  
Estefanía Trapiello

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).



2015 ◽  
Vol 65 (Pt_2) ◽  
pp. 578-586 ◽  
Author(s):  
Munusamy Madhaiyan ◽  
Selvaraj Poonguzhali ◽  
Murugaiyan Senthilkumar ◽  
Dhandapani Pragatheswari ◽  
Jung-Sook Lee ◽  
...  

Three novel bacterial strains, designated Vu-144T, Vu-7 and Vu-35, were isolated on minimal medium from rhizosphere soil of field-grown cowpea and subjected to a taxonomic study using a polyphasic approach. Cells of the strains were Gram-stain-negative, non-motile, non-spore-forming, coccoid rods, and formed non-pigmented colonies. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain Vu-144T was affiliated with an uncultivated lineage of the phylum Bacteroidetes . Its closest phylogenetic neighbour was the recently described species Niastella populi , a member of the family Chitinophagaceae , with just 90.7 % sequence similarity to the type strain. The only isoprenoid quinone detected was menaquinone 7 (MK-7). The fatty acid profiles showed large amounts of iso-C15 : 0, iso-C17 : 0 3-OH and iso-C15 : 1 G and minor amounts of summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH), C16 : 0 and other fatty acids, allowing the differentiation of the strains from other genera. The G+C content of the genomic DNA of the three strains ranged from 43.1 to 44.3 mol%. In addition to phosphatidylethanolamine, the major polar lipids were three unidentified aminophospholipids (APL1–APL3), two unidentified phospholipids (PL1, PL2) and three unidentified lipids (UL1–UL3). Biochemical test patterns also differed from those of Niastella populi and members of other genera. All three isolates showed plant-growth-promoting properties, e.g. the ability to produce indole-3-acetic acid and NH3 and to solubilize phosphate, utilized 1-aminocyclopropane 1-carboxylate (ACC) as a sole source of nitrogen and possessed the ACC deaminase enzyme. The novel isolates readily colonized roots and stimulated growth of tomato and cowpea under glasshouse conditions. Inoculated plants showed a 45–60 % increase in dry matter weight with respect to uninoculated controls. On the basis of the evidence from our polyphasic study, isolate Vu-144T represents a novel genus and species in the family Chitinophagaceae , for which the name Arachidicoccus rhizosphaerae gen. nov., sp. nov. is proposed. The type strain of Arachidicoccus rhizosphaerae is Vu-144T ( = KCTC 22378T = NCIMB 14473T).



Microbiology ◽  
2021 ◽  
Vol 167 (12) ◽  
Author(s):  
Sarah Khazaal ◽  
Rim Al Safadi ◽  
Dani Osman ◽  
Aurélia Hiron ◽  
Philippe Gilot

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.



2013 ◽  
Vol 63 (Pt_12) ◽  
pp. 4691-4697 ◽  
Author(s):  
Yi-sheng Chen ◽  
Yu-hsuan Lin ◽  
Shwu-fen Pan ◽  
Si-hua Ji ◽  
Yu-chung Chang ◽  
...  

A coccal strain isolated from fresh broccoli was initially identified as Enterococcus saccharolyticus ; however, molecular identification and phenotypic traits did not support this identification. DNA–DNA hybridization with the type strain of E. saccharolyticus (76.4 % relatedness), DNA G+C content (35.7 mol%), phylogenetic analysis based on 16S rRNA, pheS and rpoA gene sequences, rep-PCR fingerprinting and profiles of cellular fatty acids, whole-cell proteins and enzyme activities, together with carbohydrate metabolism characteristics, indicated that this strain is distinct and represents a novel subspecies, for which the name Enterococcus saccharolyticus subsp. taiwanensis subsp. nov. is proposed. The type strain is 812T ( = NBRC 109476T = BCRC 80575T). Furthermore, we present an emended description of Enterococcus saccharolyticus and proposal of Enterococcus saccharolyticus subsp. saccharolyticus subsp. nov. (type strain ATCC 43076T = CCUG 27643T = CCUG 33311T = CIP 103246T = DSM 20726T = JCM 8734T = LMG 11427T = NBRC 100493T = NCIMB 702594T).



2012 ◽  
Vol 62 (Pt_8) ◽  
pp. 1761-1765 ◽  
Author(s):  
Patrick Tailliez ◽  
Sylvie Pagès ◽  
Steve Edgington ◽  
Lukasz M. Tymo ◽  
Alan G. Buddie

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).



2015 ◽  
Vol 65 (Pt_5) ◽  
pp. 1611-1616 ◽  
Author(s):  
Syed G. Dastager ◽  
Rahul Mawlankar ◽  
Vidya V. Sonalkar ◽  
Meghana N. Thorat ◽  
Poonam Mual ◽  
...  

A Gram-stain-positive bacterium, designated strain NIO-1109T, was isolated from a marine sediment sample from Chorao Island, Goa, India. Phenotypic and chemotaxonomic characteristics and data from phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NIO-1109T was related to the genus Exiguobacterium . Strain NIO-1109T exhibited >98.0 % 16S rRNA gene sequence similarity with respect to Exiguobacterium indicum HHS 31T (99.5 %) and Exiguobacterium acetylicum NCIMB 9889T (99.1 %); the type strains of other species showed <98 % similarity. Levels of DNA–DNA relatedness between strain NIO-1109T and E. acetylicum DSM 20416T and E. indicum LMG 23471T were less than 70 % (33.0±2.0 and 37±3.2 %, respectively). Strain NIO-1109T also differed from these two closely related species in a number of phenotypic traits. Based on phenotypic, chemotaxonomic and phylogenetic data, strain NIO-1109T is considered to represent a novel species of the genus Exiguobacterium , for which the name Exiguobacterium enclense sp. nov. is proposed. The type strain is NIO-1109T ( = NCIM 5457T = DSM 25128T = CCTCC AB 2011124T).



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