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1.
Appl Environ Microbiol ; 90(7): e0092024, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-38874337

RESUMO

Marine bacteria experience fluctuations in osmolarity that they must adapt to, and most bacteria respond to high osmolarity by accumulating compatible solutes also known as osmolytes. The osmotic stress response and compatible solutes used by the coral and oyster pathogen Vibrio coralliilyticus were unknown. In this study, we showed that to alleviate osmotic stress V. coralliilyticus biosynthesized glycine betaine (GB) and transported into the cell choline, GB, ectoine, dimethylglycine, and dimethylsulfoniopropionate, but not myo-inositol. Myo-inositol is a stress protectant and a signaling molecule that is biosynthesized and used by algae. Bioinformatics identified myo-inositol (iol) catabolism clusters in V. coralliilyticus and other Vibrio, Photobacterium, Grimontia, and Enterovibrio species. Growth pattern analysis demonstrated that V. coralliilyticus utilized myo-inositol as a sole carbon source, with a short lag time of 3 h. An iolG deletion mutant, which encodes an inositol dehydrogenase, was unable to grow on myo-inositol. Within the iol clusters were an MFS-type (iolT1) and an ABC-type (iolXYZ) transporter and analyses showed that both transported myo-inositol. IolG and IolA phylogeny among Vibrionaceae species showed different evolutionary histories indicating multiple acquisition events. Outside of Vibrionaceae, IolG was most closely related to IolG from a small group of Aeromonas fish and human pathogens and Providencia species. However, IolG from hypervirulent A. hydrophila strains clustered with IolG from Enterobacter, and divergently from Pectobacterium, Brenneria, and Dickeya plant pathogens. The iol cluster was also present within Aliiroseovarius, Burkholderia, Endozoicomonas, Halomonas, Labrenzia, Marinomonas, Marinobacterium, Cobetia, Pantoea, and Pseudomonas, of which many species were associated with marine flora and fauna.IMPORTANCEHost associated bacteria such as Vibrio coralliilyticus encounter competition for nutrients and have evolved metabolic strategies to better compete for food. Emerging studies show that myo-inositol is exchanged in the coral-algae symbiosis, is likely involved in signaling, but is also an osmolyte in algae. The bacterial consumption of myo-inositol could contribute to a breakdown of the coral-algae symbiosis during thermal stress or disrupt the coral microbiome. Phylogenetic analyses showed that the evolutionary history of myo-inositol metabolism is complex, acquired multiple times in Vibrio, but acquired once in many bacterial plant pathogens. Further analysis also showed that a conserved iol cluster is prevalent among many marine species (commensals, mutualists, and pathogens) associated with marine flora and fauna, algae, sponges, corals, molluscs, crustaceans, and fish.


Assuntos
Inositol , Família Multigênica , Pressão Osmótica , Vibrio , Inositol/metabolismo , Animais , Vibrio/metabolismo , Vibrio/genética , Vibrio/fisiologia , Antozoários/microbiologia , Ostreidae/microbiologia , Betaína/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo
2.
J Org Chem ; 89(10): 7312-7319, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38683734

RESUMO

The reaction of allyl bromide derivatives with the enolate prepared from enantioenriched N-C axially chiral N-(2,5-di-tert-butylphenyl)-3,4-dihydroquinolin-2-one (lactam) and -thione (thiolactam) proceeded in a completely regio- and stereoselective manner to afford SN2 and SN2'-like products, respectively. Furthermore, through the conversion of thiolactam to lactam, the regiodivergent and stereoselective synthesis of N-C axially chiral lactams bearing a chiral tertiary α-carbon was achieved.

3.
Molecules ; 29(10)2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38792268

RESUMO

Pyrazinacenes are linearly fused heteroaromatic rings, with N atoms replacing all apical CH moieties. Component rings may exist in a reduced state, having NH groups instead of N, causing cross-conjugation. These compounds have interesting optical and electronic properties, including strong fluorescence in the near-infrared region and photocatalytic properties, leading to diverse possible applications in bio-imaging and organic synthesis, as well as obvious molecular electronic uses. In this study, we investigated the behavior of seven-ring pyrazinacene 2,3,11,12-tetraphenyl-7,16-dihydro-1,4,5,6,7,8,9,12,13,14,15,16,17,18-tetradecaazaheptacene (Ph4H2N14HEPT), with an emphasis on protic processes, including oxidation, tautomerism, deprotonation, and protonation, and the species resulting from those processes. We used computational methods to optimize the structures of the different species and generate/compare molecular orbital structures. The aromaticity of the species generated by the different processes was assessed using the nucleus-independent chemical shifts, and trends in the values were associated with the different transformations of the pyrazinacene core. The computational data were compared with experimental data obtained from synthetic samples of the molecule tBu8Ph4H2N14HEPT.

4.
Acc Chem Res ; 54(16): 3228-3240, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34323462

RESUMO

Pyrazinacenes are a class of nitrogen-containing heteroacene molecules composed of linearly fused pyrazine units, which might also include dihydropyrazine groups leading to different reduced states of the compounds. While they are structurally similar to hydrocarbon acenes (e.g., pentacene) the presence of increasing numbers of N-heteroatoms introduces several different additional features of the compounds so that they can be considered for investigations beyond those suggested for acenes (i.e., organic field-effect transistors, solar cell components). Pyrazinacenes are in several ways complementary to C-H-only acenes based on the increasing stability of reduced states of the compounds with increasing numbers of fused pyrazine rings, although an acene-like electronic structure persists in the compounds so far studied. However, the introduction of multiple N atoms leads to properties that depart from C-H-only acenes. In particular, the compounds exhibit a delocalization of NH protons in extended reduced compounds and oxidation state switchability in solution and at interfaces. The presence of NH groups also allows an easy introduction of solubilizing groups at the pyrazinacene chromophore. In this Account, we will describe the preparation of extended pyrazinacenes from dipyrazino[2,3-b:2',3'-e]pyrazine (1,4,5,8,9,10-hexaazaanthracene; N6) derivatives up to 1,4,5,6,7,8,9,12,13,14,15,16,17,18-tetradecaazaheptacene (N14) and also assess structures of the relevant compounds based on X-ray crystallographic studies. Emergent properties of the molecules include highly unusual linear tautomeric processes based on a delocalization of protons (and the corresponding formation of orbitals based on multiple adjacent N lone electron pair interactions), which suggest special transport properties based on molecular protonics. Molecules such as decazapentacene (N10) exhibit multistability of oxidation state, and this is predicted to promote the redox catalytic properties of the compounds. The oxidation-state switching of on-surface processes is also described and has been investigated using scanning tunneling microscopy. The longest known pyrazinacene chromophore (N14) exhibits amphiprotism with its state of protonation being strongly coupled to its fluorescence emission properties in the near-infrared region indicating possible uses in pH-coupled bioimaging applications. The synthesis of the pyrazinacenes is flexible and allows the preparation of symmetrically or unsymmetrically substituted derivatives for the development of more complex molecules and for control of the electronic structure of the acene unit. Overall, the pyrazinacenes represent an emerging class of highly nitrogenous heteroacenes with unique properties and excellent potential for development in different applications based on their special supramolecular properties including guest binding or interactions in biological systems.


Assuntos
Compostos Heterocíclicos/química , Pirazinas/química , Cristalografia por Raios X , Estrutura Molecular , Oxirredução , Espectrofotometria Ultravioleta
5.
Molecules ; 27(22)2022 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-36431920

RESUMO

Recently, catalytic enantioselective syntheses of N-C axially chiral compounds have been reported by many groups. Most N-C axially chiral compounds prepared through a catalytic asymmetric reaction possess carboxamide or nitrogen-containing aromatic heterocycle skeletons. On the other hand, although N-C axially chiral sulfonamide derivatives are known, their catalytic enantioselective synthesis is relatively underexplored. We found that the reaction (Tsuji-Trost allylation) of allyl acetate with secondary sulfonamides bearing a 2-arylethynyl-6-methylphenyl group on the nitrogen atom proceeds with good enantioselectivity (up to 92% ee) in the presence of (S,S)-Trost ligand-(allyl-PdCl)2 catalyst, affording rotationally stable N-C axially chiral N-allylated sulfonamides. Furthermore, the absolute stereochemistry of the major enantiomer was determined by X-ray single crystal structural analysis and the origin of the enantioselectivity was considered.


Assuntos
Paládio , Sulfonamidas , Estereoisomerismo , Paládio/química , Catálise , Sulfanilamida , Nitrogênio
6.
Appl Environ Microbiol ; 87(10)2021 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-33674441

RESUMO

Vibrio coralliilyticus and Vibrio tubiashii are pathogens responsible for high larval oyster mortality rates in shellfish hatcheries. Bacteriophage therapy was evaluated to determine its potential to remediate these mortalities. Sixteen phages against V. coralliilyticus and V. tubiashii were isolated and characterized from Hawaiian seawater. Fourteen isolates were members of the Myoviridae family, and two were members of the Siphoviridae In proof-of-principle trials, a cocktail of five phages reduced mortalities of larval Eastern oysters (Crassostrea virginica) and Pacific oysters (Crassostrea gigas) by up to 91% 6 days after challenge with lethal doses of V. coralliilyticus Larval survival depended on the oyster species, the quantities of phages and vibrios applied, and the species and strain of Vibrio A later-generation cocktail, designated VCP300, was formulated with three lytic phages subsequently named Vibrio phages vB_VcorM-GR7B, vB_VcorM-GR11A, and vB_VcorM-GR28A (abbreviated 7B, 11A, and 28A, respectively). Together, these three phages displayed host specificity toward eight V. coralliilyticus strains and a V. tubiashii strain. Larval C. gigas mortalities from V. coralliilyticus strains RE98 and OCN008 were significantly reduced by >90% (P < 0.0001) over 6 days with phage treatment compared to those of untreated controls. Genomic sequencing of phages 7B, 11A, and 28A revealed 207,758-, 194,800-, and 154,046-bp linear DNA genomes, respectively, with the latter showing 92% similarity to V. coralliilyticus phage YC, a strain from the Great Barrier Reef, Australia. Phage 7B and 11A genomes showed little similarity to phages in the NCBI database. This study demonstrates the promising potential for phage therapy to reduce larval oyster mortalities in oyster hatcheries.IMPORTANCE Shellfish hatcheries encounter episodic outbreaks of larval oyster mortalities, jeopardizing the economic stability of hatcheries and the commercial shellfish industry. Shellfish pathogens like Vibrio coralliilyticus and Vibrio tubiashii have been recognized as major contributors of larval oyster mortalities in U.S. East and West Coast hatcheries for many years. This study isolated, identified, and characterized bacteriophages against these Vibrio species and demonstrated their ability to reduce mortalities from V. coralliilyticus in larval Pacific oysters and from both V. coralliilyticus and V. tubiashii in larval Eastern oysters. Phage therapy offers a promising approach for stimulating hatchery production to ensure the well-being of hatcheries and the commercial oyster trade.


Assuntos
Bacteriófagos , Crassostrea/microbiologia , Larva/microbiologia , Terapia por Fagos , Vibrioses/terapia , Vibrio/virologia , Animais , Aquicultura/métodos , Bacteriófagos/genética , Bacteriófagos/isolamento & purificação , Mortalidade
7.
Am J Phys Anthropol ; 175(1): 201-226, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33644865

RESUMO

OBJECTIVES: We provide the first comparative description of the Guercy 1 cranium and isolated cranial fragments from Baume Moula-Guercy and examine their affinities to European Preneanderthals, Neanderthals, and Homo sapiens. MATERIALS AND METHODS: The Moula-Guercy hominins derive from deposits chronostratigraphically and biostratigraphically dated to the Eemian Interglacial (MIS 5e). For comparisons we compiled a sample of European and Southwest Asian subadult-adult Middle-to-Late Pleistocene hominins (≈MIS 14-MIS 2; N = 184). This sample represents a Preneanderthal-Neanderthal group and a H. sapiens group, both of which were further divided into three time-successive subgroups defined by associated marine isotope stages (MIS). Metric and morphological observations were made on the original fossils and a virtual reconstruction of Guercy 1. Developmental age and sex and the minimum-maximum number of individuals were assessed. RESULTS: Guercy 1 represents the remains of a late stage adolescent (≈15-16.0 years) female. Morphological and metric data combine to associate the total morphological pattern expressed in Guercy 1 with our MIS 7-MIS 5e ("Early Neanderthal") subgroup. Some features, especially those related to the frontal, suggest linkage to a paleodeme comprising the Moula-Guercy, Artenac, La Chaise Abri Suard and, possibly, the Biache-Saint-Vaast samples. DISCUSSION: Remains of MIS 7-MIS 5e Neanderthals are rare and fragmentary, especially those dated to the Last Interglacial. The Baume Moula-Guercy sample provides new insights into the total morphological pattern expressed in MIS 5e Neanderthals. Further, our results support earlier suggestions that MIS 7-MIS 5e European hominins represent a morphotype that is distinct from both earlier and later members of the Preneanderthal-Neanderthal group.


Assuntos
Homem de Neandertal/anatomia & histologia , Crânio/anatomia & histologia , Adulto , Animais , Antropologia Física , Feminino , França , Humanos , Masculino
8.
Appl Environ Microbiol ; 86(23)2020 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-32978135

RESUMO

Oyster and seawater samples were collected from five sites in the Chesapeake Bay, MD, and three sites in the Delaware Bay, DE, from May to October 2016 and 2017. Abundances and detection frequencies for total and pathogenic Vibrio parahaemolyticus and Vibrio vulnificus were compared using the standard most-probable-number-PCR (MPN-PCR) assay and a direct-plating (DP) method on CHROMagar Vibrio for total (tlh+ ) and pathogenic (tdh+ and trh+ ) V. parahaemolyticus genes and total (vvhA) and pathogenic (vcgC) V. vulnificus genes. The colony overlay procedure for peptidases (COPP) assay was evaluated for total Vibrionaceae DP had high false-negative rates (14 to 77%) for most PCR targets and was deemed unsatisfactory. Logistic regression models of the COPP assay showed high concordances with MPN-PCR for tdh+ and trh+V. parahaemolyticus and vvhA+V. vulnificus in oysters (85.7 to 90.9%) and seawater (81.1 to 92.7%) when seawater temperature and salinity were factored into the model, suggesting that the COPP assay could potentially serve as a more rapid method to detect vibrios in oysters and seawater. Differences in total Vibrionaceae and pathogenic Vibrio abundances between state sampling sites over different collection years were contrasted for oysters and seawater by MPN-PCR. Abundances of tdh+ and trh+V. parahaemolyticus were ∼8-fold higher in Delaware oysters than in Maryland oysters, whereas abundances of vcgC+V. vulnificus were nearly identical. For Delaware oysters, 93.5% were both tdh+ and trh+, compared to only 19.2% in Maryland. These results indicate that pathogenic V. parahaemolyticus was more prevalent in the Delaware Bay than in the Chesapeake Bay.IMPORTANCE While V. parahaemolyticus and V. vulnificus cause shellfish-associated morbidity and mortality among shellfish consumers, current regulatory assays for vibrios are complex, time-consuming, labor-intensive, and relatively expensive. In this study, the rapid, simple, and inexpensive COPP assay was identified as a possible alternative to MPN-PCR for shellfish monitoring. This paper shows differences in total Vibrionaceae and pathogenic vibrios found in seawater and oysters from the commercially important Delaware and Chesapeake Bays. Vibrio parahaemolyticus isolates from the Delaware Bay were more likely to contain commonly recognized pathogenicity genes than those from the Chesapeake Bay.


Assuntos
Baías/microbiologia , Ostreidae/microbiologia , Água do Mar/microbiologia , Vibrio parahaemolyticus/isolamento & purificação , Vibrio vulnificus/isolamento & purificação , Animais , Contagem de Colônia Microbiana , Delaware , Geografia , Maryland , Estações do Ano , Vibrio parahaemolyticus/classificação , Vibrio vulnificus/classificação
9.
J Am Chem Soc ; 141(50): 19570-19574, 2019 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-31736293

RESUMO

Peripherally substituted tetradecaazaheptacene (N14Hp) compounds, exhibiting amphiprotism-coupled emission, have been synthesized. X-ray crystallography reveals a planar acene-like chromophore, and electronic absorption and emission occur in the near-infrared biological transparency window (650-900 nm). The compounds exhibit long-wavelength emission with photoluminescence quantum yields ΦPL up to ∼0.61 at 686 nm, with the monodeprotonated state ΦPL ≈ 0.58 at 712 nm. This unprecedented highly nitrogenous chromophore illustrates the stability and utility of the pyrazinacenes for different applications based on their photophysical properties and chemical structures.

10.
Foodborne Pathog Dis ; 16(11): 752-760, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31144991

RESUMO

Vibrio parahaemolyticus is a common inhabitant of coastal estuaries, and can accumulate to high levels in the shellfish that populate those waters. Human gastrointestinal infection occasionally follows ingestion of raw oysters, and it can lead to extended closures of implicated oyster beds with serious economic consequences. To track down the source of human infection, and to monitor strain variation in the environment, a user-friendly and affordable typing method that provides sufficient resolution for epidemiological analysis is needed. Polymorphic locus sequence typing (PLST) is based on conventional PCR and dideoxynucleotide sequencing of the one or two most phylogenetically informative genomic loci. Bioinformatic analyses of GenBank databases identified the V. parahaemolyticus polymorphic tandem repeat-containing loci VpMT1 and VpMT2 on chromosomes 1 and 2, respectively, as promising PLST targets, yielding diversity indexes of 0.99. Phylogenetic analysis identified multiple clusters representing strains known or likely to be epidemiologically related. Correlations with serotype and multilocus sequence type were strong but resolution was higher; for example, North American ST36 strains yielded 16 VpMT1 alleles. In the laboratory, VpMT1 and VpMT2 were robust, resolving 16 of 17 strains following PCR and sequencing directly from heat-killed colonies. Finally, 4 of 13 retail oyster enrichments yielded VpMT sequences that were unique but closely related to previously characterized clinical or environmental V. parahaemolyticus isolates.


Assuntos
Tipagem de Sequências Multilocus/métodos , Vibrioses/epidemiologia , Vibrioses/microbiologia , Vibrio parahaemolyticus/classificação , Vibrio parahaemolyticus/isolamento & purificação , Animais , Doenças Transmitidas por Alimentos/epidemiologia , Doenças Transmitidas por Alimentos/microbiologia , Humanos , Epidemiologia Molecular , Ostreidae/microbiologia , Filogenia , Alimentos Marinhos/microbiologia , Especificidade da Espécie , Sequências de Repetição em Tandem , Vibrio parahaemolyticus/genética
11.
Appl Environ Microbiol ; 83(11)2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28363962

RESUMO

Pseudoalteromonas piscicida is a Gram-negative gammaproteobacterium found in the marine environment. Three strains of pigmented P. piscicida were isolated from seawater and partially characterized by inhibition studies, electron microscopy, and analysis for proteolytic enzymes. Growth inhibition and death occurred around colonies of P. piscicida on lawns of the naturally occurring marine pathogens Vibrio vulnificus, Vibrio parahaemolyticus, Vibrio cholerae, Photobacterium damselae, and Shewanella algae Inhibition also occurred on lawns of Staphylococcus aureus but not on Escherichia coli O157:H7 or Salmonella enterica serovar Typhimurium. Inhibition was not pH associated, but it may have been related to the secretion of a cysteine protease with strong activity, as detected with a synthetic fluorogenic substrate. This diffusible enzyme was secreted from all three P. piscicida strains. Direct overlay of the Pseudoalteromonas colonies with synthetic fluorogenic substrates demonstrated the activity of two aminopeptidase Bs, a trypsin-like serine protease, and enzymes reactive against substrates for cathepsin G-like and caspase 1-like proteases. In seawater cultures, scanning electron microscopy revealed numerous vesicles tethered to the outer surface of P. piscicida and a novel mechanism of direct transfer of these vesicles to V. parahaemolyticus Vesicles digested holes in V. parahaemolyticus cells, while the P. piscicida congregated around the vibrios in a predatory fashion. This transfer of vesicles and vesicle-associated digestion of holes were not observed in other bacteria, suggesting that vesicle binding may be mediated by host-specific receptors. In conclusion, we show two mechanisms by which P. piscicida inhibits and/or kills competing bacteria, involving the secretion of antimicrobial substances and the direct transfer of digestive vesicles to competing bacteria.IMPORTANCEPseudoalteromonas species are widespread in nature and reduce competing microflora by the production of antimicrobial compounds. We isolated three strains of P. piscicida and characterized secreted and cell-associated proteolytic enzymes, which may have antimicrobial properties. We identified a second method by which P. piscicida kills V. parahaemolyticus It involves the direct transfer of apparently lytic vesicles from the surface of the Pseudoalteromonas strains to the surface of Vibrio cells, with subsequent digestion of holes in the Vibrio cell walls. Enzymes associated with these vesicles are likely responsible for the digestion of holes in the cell walls. Pseudoalteromonas piscicida has potential applications in aquaculture and food safety, in control of the formation of biofilms in the environment, and in food processing. These findings may facilitate the probiotic use of P. piscicida to inactivate pathogens and may lead to the isolation of enzymes and other antimicrobial compounds of pharmacological value.


Assuntos
Proteínas de Bactérias/farmacologia , Cisteína Proteases/farmacologia , Pseudoalteromonas/enzimologia , Água do Mar/microbiologia , Vibrio parahaemolyticus/efeitos dos fármacos , Antibiose , Bactérias/classificação , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Cisteína Proteases/genética , Cisteína Proteases/metabolismo , Pseudoalteromonas/química , Pseudoalteromonas/genética , Pseudoalteromonas/isolamento & purificação , Vibrio parahaemolyticus/crescimento & desenvolvimento , Vibrio parahaemolyticus/fisiologia
12.
Appl Environ Microbiol ; 82(3): 922-7, 2016 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-26590288

RESUMO

Halobacteriovorax (formerly Bacteriovorax) is a small predatory bacterium found in the marine environment and modulates bacterial pathogens in shellfish. Four strains of Halobacteriovorax originally isolated in Vibrio parahaemolyticus O3:K6 host cells were separated from their prey by an enrichment-filtration-dilution technique for specificity testing in other bacteria. This technique was essential, since 0.45-µm filtration alone was unable to remove infectious Vibrio minicells, as determined by scanning electron microscopy and cultural methods. Purified Halobacteriovorax strains were screened for predation against other V. parahaemolyticus strains and against Vibrio vulnificus, Vibrio alginolyticus, Escherichia coli O157:H7, and Salmonella enterica serovar Typhimurium DT104, all potential threats to seafood safety. They showed high host specificity and were predatory only against strains of V. parahaemolyticus. In addition, strains of Halobacteriovorax that were predatory for E. coli O157:H7 and S. Typhimurium DT104 were isolated from a tidal river at 5 ppt salinity. In a modified plaque assay agar, they killed their respective prey over a broad range of salinities (5 to 30 ppt). Plaques became smaller as the salinity levels rose, suggesting that the lower salinities were optimal for the predators' replication. These species also showed broader host specificity, infectious against each other's original hosts as well as against V. parahaemolyticus strains. In summary, this study characterized strains of Halobacteriovorax which may be considered for use in the development of broad-based biocontrol technologies to enhance the safety of commercially marketed shellfish and other foods.


Assuntos
Agentes de Controle Biológico/isolamento & purificação , Agentes de Controle Biológico/metabolismo , Deltaproteobacteria/isolamento & purificação , Deltaproteobacteria/fisiologia , Especificidade de Hospedeiro , Água do Mar/microbiologia , Deltaproteobacteria/patogenicidade , Escherichia coli O157 , Contaminação de Alimentos/prevenção & controle , Interações Hospedeiro-Patógeno , Salinidade , Salmonella enterica , Alimentos Marinhos/microbiologia , Frutos do Mar/microbiologia , Vibrio parahaemolyticus , Vibrio vulnificus
13.
Appl Environ Microbiol ; 81(1): 292-7, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25344234

RESUMO

Vibrio tubiashii is reported to be a bacterial pathogen of larval Eastern oysters (Crassostrea virginica) and Pacific oysters (Crassostrea gigas) and has been associated with major hatchery crashes, causing shortages in seed oysters for commercial shellfish producers. Another bacterium, Vibrio coralliilyticus, a well-known coral pathogen, has recently been shown to elicit mortality in fish and shellfish. Several strains of V. coralliilyticus, such as ATCC 19105 and Pacific isolates RE22 and RE98, were misidentified as V. tubiashii until recently. We compared the mortalities caused by two V. tubiashii and four V. coralliilyticus strains in Eastern and Pacific oyster larvae. The 50% lethal dose (LD50) of V. coralliilyticus in Eastern oysters (defined here as the dose required to kill 50% of the population in 6 days) ranged from 1.1 × 10(4) to 3.0 × 10(4) CFU/ml seawater; strains RE98 and RE22 were the most virulent. This study shows that V. coralliilyticus causes mortality in Eastern oyster larvae. Results for Pacific oysters were similar, with LD50s between 1.2 × 10(4) and 4.0 × 10(4) CFU/ml. Vibrio tubiashii ATCC 19106 and ATCC 19109 were highly infectious toward Eastern oyster larvae but were essentially nonpathogenic toward healthy Pacific oyster larvae at dosages of ≥1.1 × 10(4) CFU/ml. These data, coupled with the fact that several isolates originally thought to be V. tubiashii are actually V. coralliilyticus, suggest that V. coralliilyticus has been a more significant pathogen for larval bivalve shellfish than V. tubiashii, particularly on the U.S. West Coast, contributing to substantial hatchery-associated morbidity and mortality in recent years.


Assuntos
Crassostrea/microbiologia , Vibrioses/mortalidade , Vibrioses/veterinária , Vibrio/isolamento & purificação , Animais , Larva/microbiologia , Dose Letal Mediana , Vibrio/patogenicidade , Vibrioses/microbiologia , Virulência
14.
Infect Immun ; 82(2): 544-56, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24478070

RESUMO

Vibrio parahaemolyticus is the leading cause of bacterial seafood-borne gastroenteritis worldwide, yet little is known about how this pathogen colonizes the human intestine. The alternative sigma factor RpoN/sigma-54 is a global regulator that controls flagellar synthesis, as well as a wide range of nonflagellar genes. We constructed an in-frame deletion mutation in rpoN (VP2670) in V. parahaemolyticus RIMD2210633, a clinical serogroup O3:K6 isolate, and examined the effects in vivo using a streptomycin-treated mouse model of colonization. We confirmed that deletion of rpoN rendered V. parahaemolyticus nonmotile, and it caused reduced biofilm formation and an apparent defect in glutamine synthetase production. In in vivo competition assays between the rpoN mutant and a wild-type RIMD2210633 strain marked with the ß-galactosidase gene lacZ (WBWlacZ), the mutant colonized significantly more proficiently. Intestinal persistence competition assays also demonstrated that the rpoN mutant had enhanced fitness and outcompeted WBWlacZ. Mutants defective in the polar flagellum biosynthesis FliAP sigma factor also outcompeted WBWlacZ but not to the same level as the rpoN mutant, which suggested that lack of motility is not the sole cause of the fitness effect. In an in vitro growth competition assay in mouse intestinal mucus, the rpoN mutant also outcompeted the wild type and exhibited faster doubling times when grown in mucus and on individual components of mucus. Genes in the pathways for the catabolism of mucus sugars also had significantly higher expression levels in a ΔrpoN mutant than in the wild type. These data suggest that in V. parahaemolyticus, RpoN plays an important role in carbon utilization regulation, which may significantly affect host colonization.


Assuntos
Regulação Bacteriana da Expressão Gênica , RNA Polimerase Sigma 54/metabolismo , Vibrioses/microbiologia , Vibrio parahaemolyticus/crescimento & desenvolvimento , Animais , Carbono/metabolismo , Modelos Animais de Doenças , Deleção de Genes , Masculino , Camundongos , Camundongos Endogâmicos C57BL , RNA Polimerase Sigma 54/genética , Vibrio parahaemolyticus/genética
15.
bioRxiv ; 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38766061

RESUMO

Marine bacteria experience fluctuations in osmolarity that they must adapt to, and most bacteria respond to high osmolarity by accumulating compatible solutes also known as osmolytes. The osmotic stress response and compatible solutes used by the coral and oyster pathogen Vibrio coralliilyticus were unknown. In this study, we showed that to alleviate osmotic stress V. coralliilyticus biosynthesized glycine betaine (GB) and transported into the cell choline, GB, ectoine, dimethylglycine, and dimethylsulfoniopropionate, but not myo -inositol. Myo -inositol is a stress protectant and a signaling molecule that is biosynthesized and used by algae. Bioinformatics identified myo -inositol ( iol ) catabolism clusters in V. coralliilyticus and other Vibrio, Photobacterium, Grimontia, and Enterovibrio species. Growth pattern analysis demonstrated that V. coralliilyticus utilized myo -inositol as a sole carbon source, with a short lag time of 3 h. An iolG deletion mutant, which encodes an inositol dehydrogenase, was unable to grow on myo -inositol. Within the iol clusters were an MFS-type ( iolT1) and an ABC-type ( iolXYZ) transporter and analyses showed that both transported myo -inositol. IolG and IolA phylogeny among Vibrionaceae species showed different evolutionary histories indicating multiple acquisition events. Outside of Vibrionaceae , IolG was most closely related to IolG from a small group of Aeromonas fish and human pathogens and Providencia species. However, IolG from hypervirulent A. hydrophila strains clustered with IolG from Enterobacter, and divergently from Pectobacterium, Brenneria, and Dickeya plant pathogens. The iol cluster was also present within Aliiroseovarius, Burkholderia, Endozoicomonas, Halomonas, Labrenzia, Marinomonas, Marinobacterium, Cobetia, Pantoea, and Pseudomonas, of which many species were associated with marine flora and fauna. IMPORTANCE: Host associated bacteria such as V. coralliilyticus encounter competition for nutrients and have evolved metabolic strategies to better compete for food. Emerging studies show that myo -inositol is exchanged in the coral-algae symbiosis, is likely involved in signaling, but is also an osmolyte in algae. The bacterial consumption of myo -inositol could contribute to a breakdown of the coral-algae symbiosis during thermal stress or disrupt the coral microbiome. Phylogenetic analyses showed that the evolutionary history of myo -inositol metabolism is complex, acquired multiple times in Vibrio, but acquired once in many bacterial plant pathogens. Further analysis also showed that a conserved iol cluster is prevalent among many marine species (commensals, mutualists, and pathogens) associated with marine flora and fauna, algae, sponges, corals, molluscs, crustaceans, and fish.

16.
J Am Chem Soc ; 135(14): 5262-5, 2013 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-23521041

RESUMO

Self-assembled structures formed from a pyridine-appended zinc chlorophyll derivative are reported. While the zinc complex forms cyclic oligomers in chloroform solution, as indicated by (1)H NMR studies (including diffusion-ordered spectroscopy), vapor pressure osmometry, and cold-spray ionization mass spectrometry, it forms double-stranded helical coordination polymers in the solid state, as revealed by single-crystal X-ray analysis.


Assuntos
Clorofila/química , Complexos de Coordenação/síntese química , Piridinas/química , Zinco/química , Complexos de Coordenação/química , Modelos Moleculares , Estrutura Molecular
17.
Langmuir ; 29(24): 7186-94, 2013 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-23394576

RESUMO

The development of new methodologies for controlling the organization of quantum materials in multiple dimensions is crucial to the advancement of device fabrication. By using a self-assembly route using selected imidazolium ionic liquids bearing long alkyl chains (C(n)Imida, n = 8, 10, 12) as ligands, we have achieved a tunable assembly of quantum-sized gold nanoparticles. The initial stabilizer of the gold nanoparticles was partially or wholly substituted depending on the concentration and alkyl chain length. π-π interactions between imidazolium rings also promote the generation of spatially controlled aggregates from the nanometer to micrometer size regimes. In particular, in the case of an imidazolium ionic liquid with decyl chains, gold particles assemble into a core-shell spherical superstructure induced by the aggregation of imidazolium ionic liquid molecules during ligand exchange. Conceptually, the assemblies of nanoparticles mimic biological systems and provide strategies for the organization of single-component nanomaterials into functional assemblies for potential applications. Our approach is general and can be applied to other types of nanomaterials for facile manipulation of the assembly processes, permitting an exploration of physicochemical properties as well as technological applications.

18.
Microbiol Immunol ; 57(4): 323-8, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23586636

RESUMO

Vibrio parahaemolyticus is the most common cause of bacterial, seafood-related illness in the USA. Currently, there is a dearth of published reports regarding immunity to infection with this pathogen. Here, production of both pro- and anti-inflammatory cytokines by V. parahaemolyticus-infected RAW 264.7 murine macrophages was studied. It was determined that this infection results in increased concentrations of IL-1α, IL-6, TNF-α and IL-10. Additionally, decreases in cell surface TLR2 and TLR4 and increases in T-cell co-stimulatory molecules CD40 and CD86 were discovered. The data presented here begin to identify the immune variables required to eliminate V. parahaemolyticus from infected host tissues.


Assuntos
Citocinas/biossíntese , Mediadores da Inflamação/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Vibrioses/imunologia , Vibrio parahaemolyticus/imunologia , Animais , Antígenos de Superfície/metabolismo , Citocinas/genética , Regulação da Expressão Gênica , Imunofenotipagem , Macrófagos/virologia , Camundongos , Vibrioses/genética
19.
Anat Rec (Hoboken) ; 306(3): 564-593, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36336759

RESUMO

We provide the first comparative description of the endocranium of the Guercy 1 Early Neanderthal and examine its affinities to Preneanderthals, Neanderthals, and Homo sapiens. The Guercy 1 cranium derives from deposits chronostratigraphically and biostratigraphically dated to the Eemian Interglacial (MIS 5e). For comparative purposes, we compiled a sample of European and Southwest Asian subadult and adult Middle-to-Late Pleistocene hominins (≈MIS 12-MIS 1; N = 65). We sampled both a Preneanderthal-Neanderthal group and a Homo sapiens group. The Preneanderthal-Neanderthal group was further divided into three time-successive subgroups defined by associated MIS stages. Metric and morphological observations were made on original fossils and physical and virtual endocranial reconstructions. Guercy 1 and other Early Neanderthals, differ from Preneanderthals by increased development of the prefrontal cortex, precentral and postcentral gyri, inferior parietal lobule, and frontoparietal operculum. Early Neanderthal differ, in general, from Late Neanderthals by exhibiting less development in most of the latter brain structures. The late group additionally differentiates itself from the early group by a greater development of the rostral superior parietal lobule, angular gyrus, superior and middle temporal gyri, and caudal branches of the superior temporal gyrus. Endocranial morphology assessed along the Preneanderthal-Neanderthal sequence show that brain structures prominent in Preneanderthals are accentuated in Early-to-Late Neanderthals. However, both the Early and Late groups differentiate themselves by also showing regionally specific changes in brain development. This pattern of morphological change is consistent with a mosaic pattern of neural evolution in these Middle-to-Late Pleistocene hominins.


Assuntos
Hominidae , Homem de Neandertal , Adulto , Animais , Humanos , Homem de Neandertal/anatomia & histologia , Hominidae/anatomia & histologia , Crânio/anatomia & histologia , Encéfalo , França , Fósseis , Evolução Biológica
20.
Microbiol Spectr ; 11(4): e0235323, 2023 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-37409976

RESUMO

Halobacteriovorax is a genus of naturally occurring marine predatory bacteria that attack, replicate within, and lyse vibrios and other bacteria. This study evaluated the specificity of four Halobacteriovorax strains against important sequence types (STs) of clinically relevant Vibrio parahaemolyticus, including pandemic strains ST3 and ST36. The Halobacteriovorax bacteria were previously isolated from seawater from the Mid-Atlantic, Gulf of Mexico, and Hawaiian coasts of the United States. Specificity screening was performed using a double agar plaque assay technique on 23 well-characterized and genomically sequenced V. parahaemolyticus strains isolated from infected individuals from widely varying geographic locations within the United States. With few exceptions, results showed that Halobacteriovorax bacteria were excellent predators of the V. parahaemolyticus strains regardless of the origins of the predator or prey. Sequence types and serotypes of V. parahaemolyticus did not influence host specificity, nor did the presence or absence of genes for the thermostable direct hemolysin (TDH) or the TDH-related hemolysin, although faint (cloudy) plaques were present when one or both hemolysins were absent in three of the Vibrio strains. Plaque sizes varied depending on both the Halobacteriovorax and Vibrio strains evaluated, suggesting differences in Halobacteriovorax replication and/or growth rates. The very broad infectivity of Halobacteriovorax toward pathogenic strains of V. parahaemolyticus makes Halobacteriovorax a strong candidate for use in commercial processing applications to enhance the safety of seafoods. IMPORTANCE Vibrio parahaemolyticus is a formidable obstacle to seafood safety. Strains pathogenic to humans are numerous and difficult to control, especially within molluscan shellfish. The pandemic spread of ST3 and ST36 has caused considerable concern, but many other STs are also problematic. The present study demonstrates broad predatory activity of Halobacteriovorax strains obtained along U.S. coastal waters from the Mid-Atlantic, Gulf Coast, and Hawaii toward strains of pathogenic V. parahaemolyticus. This broad activity against clinically relevant V. parahaemolyticus strains suggests a role for Halobacteriovorax in mediating pathogenic V. parahaemolyticus levels in seafoods and their environment as well as the potential application of these predators in the development of new disinfection technologies to reduce pathogenic vibrios in molluscan shellfish and other seafoods.


Assuntos
Proteínas Hemolisinas , Vibrio parahaemolyticus , Humanos , Proteínas Hemolisinas/genética , Vibrio parahaemolyticus/genética , Frutos do Mar/microbiologia , Proteobactérias
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