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.

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).

Enterococcus saccharolyticus subsp. taiwanensis subsp. nov., isolated from broccoli

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 ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Dna Hybridization ◽  
Type Strain ◽  
Type Species ◽  
Phenotypic Traits ◽  
Strain Atcc ◽  
Content Type ◽  
Cellular Fatty Acids ◽  
Link Type ◽  
Emended Description

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).

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).

scholarly journals Comparative polyphasic characterization of Streptococcus phocae strains with different host origin and description of the subspecies Streptococcus phocae subsp. salmonis subsp. nov.

2014 ◽  
Vol 64 (Pt_5) ◽  
pp. 1775-1781 ◽  
Author(s):  
Ruben Avendaño-Herrera ◽  
Sabela Balboa ◽  
Nuria Castro ◽  
Alberto González-Contreras ◽  
Beatriz Magariños ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Type Species ◽  
Growth Media ◽  
Major Protein ◽  
Species Definition ◽  
Content Type ◽  
Columbia Blood Agar ◽  
Link Type ◽  
Major Protein Band ◽  
Host Origin

A polyphasic study was undertaken to clarify the taxonomic position of Streptococcus phocae strains isolated from Atlantic salmon (Salmo salar) cage-farmed in Chile. Four salmon and three seal isolates showed minor differences in the SDS-PAGE protein analysis. Thus, a major protein band present in the salmon isolates, of approximately 22.4 kDa, was absent in the pinniped strains, regardless of the growth media employed. In addition, the pinniped strains showed protein bands with molecular masses of 71.5 and 14.2 kDa, when grown on trypticase soy agar supplemented with 1 % NaCl, or 25.6 kDa, when grown on Columbia blood agar, not present in the Atlantic salmon strains. A high similarity in the matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS spectra of the strains was observed, although some minor peaks were absent in the fish isolates. Fatty acid methyl esters from isolates with different host origin significantly (P<0.05) differed in the content of C16 : 0, C17 : 0, C18 : 1ω9c, C20 : 4ω6,9,12,15c and summed features 3, 5 and 8. The salmon isolates formed a separate cluster in the phylogenetic analysis of housekeeping genes, separately or as concatenated sequences. Sequence divergences among salmon and seal strains were in the range of inter-subspecies differentiation for groEL (2.5 %), gyrB (1.8 %), recN (2.1 %), rpoB (1.7 %) and sodA (2.0 %) genes. DNA–DNA hybridization results confirmed those of sequencing, showing reassociation values between seal and salmon strains close to the borderline of species definition. Differences in growth at low temperatures and in the haemolytic capacities were also observed between both groups of isolates. On the basis of all these results, the salmon isolates represent a novel subspecies of S. phocae , for which the name Streptococcus phocae subsp. salmonis subsp. nov. is proposed. The type strain is C-4T ( = CECT 7921T = DSM 24768T). The subspecies Streptococcus phocae subsp. phocae subsp. nov. is automatically created. An emended description of S. phocae is also provided.

scholarly journals Exiguobacterium enclense sp. nov., isolated from sediment

2015 ◽  
Vol 65 (Pt_5) ◽  
pp. 1611-1616 ◽  
Author(s):  
Syed G. Dastager ◽  
Rahul Mawlankar ◽  
Vidya V. Sonalkar ◽  
Meghana N. Thorat ◽  
Poonam Mual ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Type Species ◽  
Sequence Similarity ◽  
Phenotypic Traits ◽  
Rrna Gene ◽  
Closely Related Species ◽  
Content Type ◽  
Link Type ◽  
Marine Sediment Sample

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).

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.

scholarly journals Combinatorial quorum sensing in Pseudomonas aeruginosa allows for novel cheating strategies

Microbiology ◽  
2020 ◽  
Vol 166 (8) ◽  
pp. 777-784 ◽  
Author(s):  
James Gurney ◽  
Sheyda Azimi ◽  
Sam P. Brown ◽  
Stephen P. Diggle
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Type Species ◽  
Natural Populations ◽  
Opportunistic Pathogen ◽  
Growth Media ◽  
Public And Private ◽  
Content Type ◽  
Private Goods ◽  
Link Type

In the opportunistic pathogen Pseudomonas aeruginosa, quorum sensing (QS) is a social trait that is exploitable by non-cooperating cheats. Previously it has been shown that by linking QS to the production of both public and private goods, cheats can be prevented from invading populations of cooperators and this was described by Dandekar et al. (Science 2012;338:264–266) as ‘a metabolic incentive to cooperate’. We hypothesized that P. aeruginosa could evolve novel cheating strategies to circumvent private goods metabolism by rewiring its combinatorial response to two QS signals (3O-C12-HSL and C4-HSL). We performed a selection experiment that cycled P. aeruginosa between public and private goods growth media and evolved an isolate that rewired its control of cooperative protease expression from a synergistic (AND-gate) response to dual-signal input to a 3O-C12-HSL-only response. We show that this isolate circumvents metabolic incentives to cooperate and acts as a combinatorial signalling cheat, with higher fitness in competition with its ancestor. Our results show three important principles: first, combinatorial QS allows for diverse social strategies to emerge; second, restrictions levied by private goods are not sufficient to explain the maintenance of cooperation in natural populations; and third, modifying combinatorial QS responses could result in important physiological outcomes in bacterial populations.

scholarly journals A novel hemA mutation is responsible for a small-colony-variant phenotype in Escherichia coli

Microbiology ◽  
2020 ◽  
Author(s):  
Alasdair T. M. Hubbard ◽  
Issra Bulgasim ◽  
Adam P. Roberts
Keyword(s):  
Escherichia Coli ◽  
Mammalian Cells ◽  
Type Species ◽  
Fitness Cost ◽  
Growth Media ◽  
Content Type ◽  
Small Colony Variant ◽  
Link Type ◽  
Small Colony ◽  
Tract Infections

We identified a small colony variant (SCV) of an amoxicillin/clavulanic acid-resistant derivative of a clinical isolate of Escherichia coli from Malawi, which was selected for in vitro in a subinhibitory concentration of gentamicin. The SCV was auxotrophic for hemin and had impaired biofilm formation compared to the ancestral isolates. A single novel nucleotide polymorphism (SNP) in hemA, which encodes a glutamyl-tRNA reductase that catalyses the initial step of porphyrin biosynthesis leading to the production of haem, was responsible for the SCV phenotype. We showed the SNP in hemA resulted in a significant fitness cost to the isolate, which persisted even in the presence of hemin. However, the phenotype quickly reverted during sequential sub-culturing in liquid growth media. As hemA is not found in mammalian cells, and disruption of the gene results in a significant fitness cost, it represents a potential target for novel drug development specifically for the treatment of catheter-associated urinary tract infections caused by E. coli .

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