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1.
Prog Chem Org Nat Prod ; 111: 81-153, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32114663

RESUMO

Marine-derived fungi play an important role in the search for structurally unique secondary metabolites, some of which show promising pharmacological activities that make them useful leads for drug discovery. Marine natural product research in China in general has made enormous progress in the last two decades as described in this chapter on fungal metabolites. This contribution covers 613 new natural products reported from 2001 to 2017 from marine-derived fungi obtained from algae, sponges, corals, and other marine organisms from Chinese waters. The genera Aspergillus (170 new natural products, 28%) and Penicillium (70 new natural products, 11%) were the main fungal producers of new natural products during the time period covered, whereas sponges (184 new natural products, 30%) were the most abundant source of new natural products, followed by corals (154 new natural products, 25%) and algae (130 new natural products, 21%). Close to 40% of all natural products covered in this contribution displayed various bioactivities. The major bioactivities reported were cytotoxicity against different cancer cell lines, antimicrobial (mainly antibacterial) activity, and antiviral activity, which accounted for 13%, 9%, and 3% of all natural products reported. In terms of structural classes, polyketides (188 new natural products, 31%) play a dominant role, and if prenylated polyketides and nitrogen-containing polyketides (included in meroterpenes and alkaloids in this contribution) are taken into account, their total number even exceeds 50%. Nitrogen-containing compounds including peptides (65 new natural products, 10%) and alkaloids (103 new natural products, 17%) are the second largest group.


Assuntos
Produtos Biológicos/farmacologia , Fungos/química , Policetídeos/farmacologia , Animais , Antozoários/microbiologia , Anti-Infecciosos , Antineoplásicos , Organismos Aquáticos/microbiologia , Aspergillus/química , Produtos Biológicos/química , China , Penicillium/química , Policetídeos/química , Poríferos/microbiologia , Metabolismo Secundário
2.
Arch Microbiol ; 202(4): 815-824, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31844948

RESUMO

Kiloniella laminariae is a true marine bacterium and the first member of the family and order, the Kiloniellaceae and Kiloniellales. K. laminariae LD81T (= DSM 19542T) was isolated from the marine macroalga Saccharina latissima and is a mesophilic, typical marine chemoheterotrophic aerobic bacterium with antifungal activity. Phylogenetic analysis of 16S rRNA gene sequence revealed the similarity of K. laminariae LD81T not only with three validly described species of the genus Kiloniella, but also with undescribed isolates and clone sequences from marine samples in the range of 93.6-96.7%. We report on the analysis of the draft genome of this alphaproteobacterium and describe some selected features. The 4.4 Mb genome has a G + C content of 51.4%, contains 4213 coding sequences including 51 RNA genes as well as 4162 protein-coding genes, and is a part of the Genomic Encyclopaedia of Bacteria and Archaea (GEBA) project. The genome provides insights into a number of metabolic properties, such as carbon and sulfur metabolism, and indicates the potential for denitrification and the biosynthesis of secondary metabolites. Comparative genome analysis was performed with K. laminariae LD81T and the animal-associated species Kiloniella majae M56.1T from a spider crab, Kiloniella spongiae MEBiC09566T from a sponge as well as Kiloniella litopenai P1-1 from a white shrimp, which all inhabit quite different marine habitats. The analysis revealed that the K. laminariae LD81T contains 1397 unique genes, more than twice the amount of the other species. Unique among others is a mixed PKS/NRPS biosynthetic gene cluster with similarity to the biosynthetic gene cluster responsible for the production of syringomycin.


Assuntos
Alphaproteobacteria/genética , Organismos Aquáticos/genética , Genômica , Filogenia , Alphaproteobacteria/classificação , Animais , Organismos Aquáticos/classificação , Organismos Aquáticos/microbiologia , Proteínas de Bactérias/genética , Composição de Bases , Feófitas/microbiologia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Especificidade da Espécie
3.
PLoS Biol ; 17(11): e3000533, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31710600

RESUMO

The significance of symbioses between eukaryotic hosts and microbes extends from the organismal to the ecosystem level and underpins the health of Earth's most threatened marine ecosystems. Despite rapid growth in research on host-associated microbes, from individual microbial symbionts to host-associated consortia of significantly relevant taxa, little is known about their interactions with the vast majority of marine host species. We outline research priorities to strengthen our current knowledge of host-microbiome interactions and how they shape marine ecosystems. We argue that such advances in research will help predict responses of species, communities, and ecosystems to stressors driven by human activity and inform future management strategies.


Assuntos
Organismos Aquáticos/microbiologia , Microbiota/fisiologia , Simbiose/fisiologia , Animais , Bactérias/classificação , Ecossistema , Interações entre Hospedeiro e Microrganismos/fisiologia , Humanos
4.
Mar Drugs ; 17(10)2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31575010

RESUMO

Chlorophenols (CPs) are environmental pollutants that are produced through various anthropogenic activities and introduced in the environment. Living organisms, including humans, are exposed to these toxic xenobiotics and suffer from adverse health effects. More specifically, 2,4-dichlorophenol (2,4-DCP) is released in high amounts in the environment and has been listed as a priority pollutant by the US Environmental Protection Agency. Bioremediation has been proposed as a sustainable alternative to conventional remediation methods for the detoxification of phenolic compounds. In this work, we studied the potential of fungal strains isolated as symbionts of marine invertebrates from the underexplored mesophotic coral ecosystems. Hence, the unspecific metabolic pathways of these fungal strains are being explored in the present study, using the powerful analytical capabilities of a UHPLC-HRMS/MS. The newly identified 2,4-DCP metabolites add significantly to the knowledge of the transformation of such pollutants by fungi, since such reports are scarce.


Assuntos
Organismos Aquáticos/microbiologia , Clorofenóis/metabolismo , Fungos/metabolismo , Invertebrados/microbiologia , Poluentes Químicos da Água/metabolismo , Animais , Antozoários/metabolismo , Biodegradação Ambiental , Ecossistema , Humanos , Redes e Vias Metabólicas/fisiologia , Fenóis/metabolismo , Simbiose/fisiologia , Xenobióticos/metabolismo
5.
BMC Infect Dis ; 19(1): 916, 2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31664927

RESUMO

BACKGROUND: Vibrio cholerae non-O1 is a virulent pathogen that causes significant morbidity and mortality in humans. Herein, we report a case of corneal ulcer caused by this pathogen. CASE PRESENTATION: A 59-year-old fisherman with no systemic history was struck in the right eye by a marine shrimp and developed keratitis. Corneal scrapping culture revealed the presence of the V. cholerae non-O1, and its identification was confirmed by Analytical Profile Index 20E system and polymerase chain reaction. He was successfully treated with topical levofloxacin (0.3%) and fortified amikacin (12.5 mg/mL) for 2 weeks. The visual acuity recovered to 20/25 after treatment without complications. CONCLUSIONS: This is the first case report of keratitis caused by V. cholerae non-O1 strain. Ocular injury by marine creatures and contaminated seawater can contribute to severe corneal ulcer. Early diagnosis can be achieved by meticulous history taking and a comprehensive laboratory workup. Simultaneously, an effective antibiotic therapy can lead to a positive outcome.


Assuntos
Ceratite/microbiologia , Vibrioses/microbiologia , Vibrio cholerae não O1/isolamento & purificação , Administração Tópica , Amicacina/administração & dosagem , Amicacina/uso terapêutico , Antibacterianos/administração & dosagem , Antibacterianos/uso terapêutico , Organismos Aquáticos/microbiologia , Úlcera da Córnea/microbiologia , Olho/microbiologia , Olho/patologia , Humanos , Ceratite/tratamento farmacológico , Levofloxacino/administração & dosagem , Levofloxacino/uso terapêutico , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Água do Mar/microbiologia , Resultado do Tratamento , Vibrioses/tratamento farmacológico , Vibrio cholerae não O1/genética
6.
Molecules ; 24(14)2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31336683

RESUMO

Four new compounds, including two new polyketides, heterocornols M and N (1, 2), and a pair of epimers, heterocornols O and P (3, 4), were isolated from the fermentation broth of the marine sponge-derived fungus Pestalotiopsis heterocornis XWS03F09, together with three known compounds (5-7). The new chemical structures were established on the basis of a spectroscopic analysis, optical rotation, experimental and calculated electronic circular dichroism (ECD). All of the compounds (1-7) were evaluated for their cytotoxic activities, and heterocornols M-P (1-4) exhibited cytotoxicities against four human cancer cell lines with IC50 values of 20.4-94.2 µM.


Assuntos
Organismos Aquáticos/microbiologia , Ascomicetos/química , Produtos Biológicos/farmacologia , Policetídeos/farmacologia , Poríferos/microbiologia , Animais , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Modelos Moleculares , Estrutura Molecular , Policetídeos/química , Policetídeos/isolamento & purificação , Análise Espectral
7.
Sci Total Environ ; 686: 264-275, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31181514

RESUMO

Seagrass meadows store globally-significant quantities of organic 'blue' carbon. These blue carbon stocks are potentially vulnerable to anthropogenic stressors (e.g. coastal development, climate change). Here, we tested the impact of oxygen exposure and warming (major consequences of human disturbance) on rates of microbial carbon break-down in seagrass sediments. Active microbes occurred throughout seagrass sediment profiles, but deep, ancient sediments (~5000 yrs. old) contained only 3% of the abundance of active microbes as young, surface sediments (<2 yrs. old). Metagenomic analysis revealed that microbial community structure and function changed with depth, with a shift from proteobacteria and high levels of genes involved in sulfur cycling in the near surface samples, to a higher proportion of firmicutes and euraracheota and genes involved in methanogenesis at depth. Ancient carbon consisted almost entirely (97%) of carbon considered 'thermally recalcitrant', and therefore presumably inaccessible to microbial attack. Experimental warming had little impact on carbon; however, exposure of ancient sediments to oxygen increased microbial abundance, carbon uptake and sediment carbon turnover (34-38 fold). Overall, this study provides detailed characterization of seagrass blue carbon (chemical stability, age, associated microbes) and suggests that environmental disturbances that expose coastal sediments to oxygen (e.g. dredging) have the capacity to diminish seagrass sediment carbon stocks by facilitating microbial remineralisation.


Assuntos
Mudança Climática , Poaceae/microbiologia , Organismos Aquáticos/microbiologia , Carbono/análise , Sequestro de Carbono , Oxigênio , Proteobactérias , Microbiologia da Água
8.
Fungal Biol ; 123(7): 507-516, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31196520

RESUMO

In the present study, we surveyed the distribution and diversity of fungal assemblages associated with 10 species of marine animals from Antarctica. The collections yielded 83 taxa from 27 distinct genera, which were identified using molecular biology methods. The most abundant taxa were Cladosporium sp. 1, Debaryomyces hansenii, Glaciozyma martinii, Metschnikowia australis, Pseudogymnoascus destructans, Thelebolus cf. globosus, Pseudogymnoascus pannorum, Tolypocladium tundrense, Metschnikowia australis, and different Penicillium species. The diversity, richness, and dominance of fungal assemblages ranged among the host; however, in general, the fungal community, which was composed of endemic and cold-adapted cosmopolitan taxa distributed across the different sites of Antarctic Peninsula, displayed high diversity, richness, and dominance indices. Our results contribute to knowledge about fungal diversity in the marine environment across the Antarctic Peninsula and their phylogenetic relationships with species that occur in other cold, temperate, and tropical regions of the World. Additionally, despite their extreme habitats, marine Antarctic animals shelter cryptic and complex fungal assemblages represented by endemic and cosmopolitan cold-adapted taxa, which may represent interesting models to study different symbiotic associations between fungi and their animal hosts in the extreme conditions of Antarctica.


Assuntos
Organismos Aquáticos/microbiologia , Biodiversidade , Fungos/classificação , Fungos/crescimento & desenvolvimento , Micobioma/fisiologia , Filogenia , Animais , Regiões Antárticas , Extremófilos/classificação , Extremófilos/genética , Extremófilos/crescimento & desenvolvimento , Extremófilos/isolamento & purificação , Fungos/genética , Fungos/isolamento & purificação
9.
Antonie Van Leeuwenhoek ; 112(10): 1567-1575, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31147966

RESUMO

A novel Gram-negative bacterium, non-motile and short rod-shaped, designated strain GY511T, was isolated from the intestines of fish collected from Maowei Sea, China. Growth occurred at pH 6.0-9.0 (optimum 7.0), 4-37 °C (optimum 28 °C) and at 0-2.5% (w/v) NaCl (optimum 1.0%). The result of 16S rRNA gene sequence analysis showed that strain GY511T is closely related to O. oryzae NBRC 113109T (97.6%), O. konkukae DSM 105395T (97.4%), Ottowia beijingensis CGMCC 1.12324T (95.9%), Ottowia pentelensis DSM 21699T (95.2%) and Ottowia thiooxydans DSM 14619T (95.0%). The DNA-DNA hybridization values of strain GY511T with O. oryzae NBRC 113109T and O. konkukae DSM 105395T were 35.4 ± 3.1% and 26.3 ± 1.8%, respectively. The major fatty acids (> 10%) were identified as summed feature 3 (C16:1ω7c and/or C16:1ω6c), C16:0 and summed feature 8 (C18:1ω7c and/or C18:1ω6c) and the major respiratory quinone was ubiquinone-8 (Q-8). The polar lipids comprised diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylmethylethanolamine, two unidentified aminolipids and an unidentified phospholipid. The G+C content of the genomic DNA was 62.9 mol%. Thiosulfate could be utilized as co-substrate for aerobic growth and was oxidised to sulfate. On the basis of phenotypic, chemotaxonomic and molecular data, strain GY511T is considered to represent a novel species of the genus Ottowia, for which the name Ottowia flava sp. nov. is proposed. The type strain is GY511T (= NBRC 113500T = DSM 107425T = CGMCC 1.13650T).


Assuntos
Comamonadaceae/classificação , Comamonadaceae/isolamento & purificação , Peixes/microbiologia , Intestinos/microbiologia , Aerobiose , Animais , Organismos Aquáticos/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , China , Análise por Conglomerados , Comamonadaceae/genética , Comamonadaceae/fisiologia , Citosol/química , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Ácidos Graxos/análise , Concentração de Íons de Hidrogênio , Hibridização de Ácido Nucleico , Fosfolipídeos/análise , Filogenia , Quinonas/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Cloreto de Sódio/metabolismo , Temperatura
10.
mBio ; 10(3)2019 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-31239380

RESUMO

Since the discovery of symbioses between sulfur-oxidizing (thiotrophic) bacteria and invertebrates at hydrothermal vents over 40 years ago, it has been assumed that autotrophic fixation of CO2 by the symbionts drives these nutritional associations. In this study, we investigated "Candidatus Kentron," the clade of symbionts hosted by Kentrophoros, a diverse genus of ciliates which are found in marine coastal sediments around the world. Despite being the main food source for their hosts, Kentron bacteria lack the key canonical genes for any of the known pathways for autotrophic carbon fixation and have a carbon stable isotope fingerprint that is unlike other thiotrophic symbionts from similar habitats. Our genomic and transcriptomic analyses instead found metabolic features consistent with growth on organic carbon, especially organic and amino acids, for which they have abundant uptake transporters. All known thiotrophic symbionts have converged on using reduced sulfur to gain energy lithotrophically, but they are diverse in their carbon sources. Some clades are obligate autotrophs, while many are mixotrophs that can supplement autotrophic carbon fixation with heterotrophic capabilities similar to those in Kentron. Here we show that Kentron bacteria are the only thiotrophic symbionts that appear to be entirely heterotrophic, unlike all other thiotrophic symbionts studied to date, which possess either the Calvin-Benson-Bassham or the reverse tricarboxylic acid cycle for autotrophy.IMPORTANCE Many animals and protists depend on symbiotic sulfur-oxidizing bacteria as their main food source. These bacteria use energy from oxidizing inorganic sulfur compounds to make biomass autotrophically from CO2, serving as primary producers for their hosts. Here we describe a clade of nonautotrophic sulfur-oxidizing symbionts, "Candidatus Kentron," associated with marine ciliates. They lack genes for known autotrophic pathways and have a carbon stable isotope fingerprint heavier than other symbionts from similar habitats. Instead, they have the potential to oxidize sulfur to fuel the uptake of organic compounds for heterotrophic growth, a metabolic mode called chemolithoheterotrophy that is not found in other symbioses. Although several symbionts have heterotrophic features to supplement primary production, in Kentron they appear to supplant it entirely.


Assuntos
Processos Autotróficos , Bactérias/genética , Ciclo do Carbono/genética , Cilióforos/microbiologia , Enxofre/metabolismo , Simbiose , Organismos Aquáticos/microbiologia , Bactérias/metabolismo , Dióxido de Carbono/metabolismo , Perfilação da Expressão Gênica , Genômica , Itália , Oxirredução , RNA Ribossômico 16S/genética
11.
Environ Pollut ; 248: 989-999, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31091643

RESUMO

Gut microbial communities constitute a compartment of crucial importance in regulation of homeostasis of multiple host physiological functions as well as in resistance towards environmental pollutants. Many chemical contaminants were shown to constitute a major threat for gut bacteria. Changes in gut microbiome could lead to alteration of host health. The access to high-throughput sequencing platforms permitted a great expansion of this discipline in human health while data from ecotoxicological studies are scarce and particularly those related to aquatic pollution. The main purpose of this review is to summarize recent body of literature providing data obtained from microbial community surveys using high-throughput 16S rRNA sequencing technology applied to aquatic ecotoxicity. Effects of pesticides, PCBs, PBDEs, heavy metals, nanoparticles, PPCPs, microplastics and endocrine disruptors on gut microbial communities are presented and discussed. We pointed out difficulties and limits provided by actual methodologies. We also proposed ways to improve understanding of links between changes in gut bacterial communities and host fitness loss, along with further applications for this emerging discipline.


Assuntos
Bactérias/efeitos dos fármacos , Disruptores Endócrinos/toxicidade , Microbioma Gastrointestinal/efeitos dos fármacos , Éteres Difenil Halogenados/toxicidade , Metais Pesados/toxicidade , Praguicidas/toxicidade , Plásticos/toxicidade , Poluentes Químicos da Água/toxicidade , Anfíbios/microbiologia , Animais , Organismos Aquáticos/microbiologia , Bactérias/classificação , Bactérias/genética , Ecotoxicologia , Peixes/microbiologia , Humanos , Microbiota/efeitos dos fármacos , RNA Ribossômico 16S/genética
12.
Curr Microbiol ; 76(6): 713-722, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30968206

RESUMO

Despite the broad assessment of sponge bacterial diversity through cultivation-independent and dependent strategies, the knowledge focusing on cultivable anaerobes from this holobiont is still incipient. Plakina is a genus with the highest number of described species from the smallest of poriferan classes, Homoscleromorpha. The Brazilian Atlantic coast has been presenting itself as a hotspot for the discovery of new plakinidae species, with initial surveys just now concerning to characterize their microbiome. The current study aimed to isolate and identify strict anaerobes from recently described species of Plakina collected at the coast of Cabo Frio, RJ. Samples of four sympatric morphotypes of Plakina cyanorosea and Plakina cabofriense were collected on the coast of Cabo Frio, RJ. Using five different culture media, a total of 93 bacterial isolates were recovered, among which 60 were strict anaerobes and, ultimately, 34 remaining viable. A total of 76.5% from these strains were mostly identified as Clostridium bifermentans by mass spectrometry and 82.4% identified by 16S rRNA sequencing, almost all of them affiliated to the genus Paraclostridium, and with one isolate identified as Clostridium butyricum by both techniques. None of the anaerobic bacteria exhibited antimicrobial activity by the adopted screening test. The present work highlights not only the need for cultivation and characterization of the anaerobic microbiota from marine sponges but also adds the existing scarce knowledge of culturable bacterial communities from Homoscleromorph sponges from Brazilian coast.


Assuntos
Bactérias Anaeróbias/classificação , Bactérias Anaeróbias/isolamento & purificação , Clostridiales/classificação , Clostridiales/isolamento & purificação , Poríferos/microbiologia , Aerobiose , Anaerobiose , Animais , Anti-Infecciosos/metabolismo , Organismos Aquáticos/microbiologia , Oceano Atlântico , Bactérias Anaeróbias/química , Bactérias Anaeróbias/genética , Técnicas Bacteriológicas , Brasil , Clostridiales/química , Clostridiales/genética , Clostridium bifermentans , Clostridium butyricum , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Espectrometria de Massas , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
13.
J Basic Microbiol ; 59(7): 692-700, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30980726

RESUMO

Salt stable cellulases are implicated in detritic food webs of marine invertebrates for their role in the degradation of cellulosic material. A haloarchaeon, Haloferax sulfurifontis GUMFAZ2 producing cellulase was successfully isolated from marine Haliclona sp., a sponge inhabiting the rocky intertidal region of Anjuna, Goa. The culture produced extracellular xylanase-free cellulase with a maximum activity of 11.7 U/ml, using carboxymethylcellulose-Na (CMC-Na), as a sole source of carbon in 3.5 M NaCl containing medium, pH 7 at 40°C and produced cellobiose and glucose, detectable by thin-layer chromatography. Nondenaturing polyacrylamide gel electrophoresis of the crude enzyme, revealed a single protein band of 19.6 kDa which on zymographic analysis exhibited cellulase activity while corresponding sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed a molecular weight of 46 kDa. Unlike conventional cellulases, this enzyme is active in presence of 5 M NaCl and does not have accompanying xylanase activity, hence can be considered as xylanase-free cellulase. Such enzymes from haloarchaea offer great potential for biotechnological application because of their stability at high salinity and is therefore worth pursuing.


Assuntos
Celulase/isolamento & purificação , Celulase/metabolismo , Haliclona/microbiologia , Haloferax/enzimologia , Animais , Organismos Aquáticos/enzimologia , Organismos Aquáticos/microbiologia , Carboximetilcelulose Sódica/metabolismo , Celulase/química , Celulase/fisiologia , Estabilidade Enzimática , Haliclona/classificação , Haloferax/classificação , Haloferax/fisiologia , Concentração de Íons de Hidrogênio , Índia , Microbiota/genética , Microbiota/fisiologia , Peso Molecular , Filogenia , Salinidade , Especificidade por Substrato , Temperatura
14.
Mar Drugs ; 17(3)2019 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-30934619

RESUMO

Saline environments, such as marine and hypersaline habitats, are widely distributed around the world. They include sea waters, saline lakes, solar salterns, or hypersaline soils. The bacteria that live in these habitats produce and develop unique bioactive molecules and physiological pathways to cope with the stress conditions generated by these environments. They have been described to produce compounds with properties that differ from those found in non-saline habitats. In the last decades, the ability to disrupt quorum-sensing (QS) intercellular communication systems has been identified in many marine organisms, including bacteria. The two main mechanisms of QS interference, i.e., quorum sensing inhibition (QSI) and quorum quenching (QQ), appear to be a more frequent phenomenon in marine aquatic environments than in soils. However, data concerning bacteria from hypersaline habitats is scarce. Salt-tolerant QSI compounds and QQ enzymes may be of interest to interfere with QS-regulated bacterial functions, including virulence, in sectors such as aquaculture or agriculture where salinity is a serious environmental issue. This review provides a global overview of the main works related to QS interruption in saline environments as well as the derived biotechnological applications.


Assuntos
Organismos Aquáticos/microbiologia , Infecções Bacterianas/prevenção & controle , Bacilos Gram-Negativos Anaeróbios Facultativos/fisiologia , Percepção de Quorum/efeitos dos fármacos , Água do Mar/microbiologia , Animais , Antibacterianos/farmacologia , Aquicultura , Biofilmes/efeitos dos fármacos , Bacilos Gram-Negativos Anaeróbios Facultativos/efeitos dos fármacos , Percepção de Quorum/fisiologia , Salinidade , Áreas Alagadas
15.
Mar Drugs ; 17(4)2019 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-30934741

RESUMO

Vibrio diabolicus A1SM3 strain was isolated from a sediment sample from Manaure Solar Saltern in La Guajira and the produced crude extracts have shown antibacterial activity against methicillin-resistant Staphylococcus aureus and cytotoxic activity against human lung cell line. Thus, the aim of this research was to identify the main compound responsible for the biological activity observed and to systematically study how each carbon and nitrogen source in the growth media, and variation of the salinity, affect its production. For the characterization of the bioactive metabolites, 15 fractions obtained from Vibrio diabolicus A1SM3 crude extract were analyzed by HPLC-MS/MS and their activity was established. The bioactive fractions were dereplicated with Antibase and Marinlit databases, which combined with nuclear magnetic resonance (NMR) spectra and fragmentation by MS/MS, led to the identification of 2,2-di(3-indolyl)-3-indolone (isotrisindoline), an indole-derivative antibiotic, previously isolated from marine organisms. The influence of the variations of the culture media in isotrisindoline production was established by molecular network and MZmine showing that the media containing starch and peptone at 7% NaCl was the best culture media to produce it. Also, polyhydroxybutyrates (PHB) identification was established by MS/MS mainly in casamino acids media, contributing to the first report on PHB production by this strain.


Assuntos
Antibacterianos/biossíntese , Antibacterianos/farmacologia , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Técnicas Bacteriológicas/métodos , Vibrio/química , Vibrio/metabolismo , Alcaloides/biossíntese , Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Antibacterianos/isolamento & purificação , Antineoplásicos/isolamento & purificação , Organismos Aquáticos/microbiologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Misturas Complexas/química , Misturas Complexas/isolamento & purificação , Meios de Cultura , Humanos , Hidroxibutiratos/química , Hidroxibutiratos/farmacologia , Isoindóis/isolamento & purificação , Isoindóis/metabolismo , Modelos Moleculares , Poliésteres/química , Poliésteres/farmacologia , Poli-Hidroxialcanoatos/química , Poli-Hidroxialcanoatos/farmacologia , Salinidade
16.
Mar Drugs ; 17(3)2019 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-30857186

RESUMO

Marennine, the water-soluble blue pigment produced by the marine diatom Haslea ostrearia, is known to display antibacterial activities. Previous studies have demonstrated a prophylactic effect of marennine on bivalve larvae challenged with a pathogenic Vibrio splendidus, suggesting that the blue Haslea is a good candidate for applications in aquaculture as a source of a natural antimicrobial agent. Indeed, the genus Vibrio is ubiquitous in aquaculture ecosystems, and regular events of pathogenic invasion cause some of the biggest losses worldwide. To better characterize the effects of marennine on Vibrios, a panel of 30 Vibrio strains belonging to 10 different species was tested, including bivalve pathogenic species (e.g., Vibrio crassostreae and Vibrio harveyi). Vibrio strains were first exposed to 10 and 25 µg mL-1 of Blue Water (BW), a concentrated culture supernatant of H. ostrearia containing marennine. This screening evidenced a great diversity in responses, from growth stimulation to a total inhibition, at both the interspecific or intraspecific level. In a second series of experiments, 10 Vibrio strains were exposed to BW at concentrations ranging from 5 to 80 µg mL-1. The highest concentrations of BW did not systematically result in the highest growth inhibition as hormetic responses-opposite effects regarding the concentration-were occasionally evidenced. The relationships between marennine and Vibrio strains appear more complex than expected and justify further study-in particular, on the mechanisms of action-before considering applications as a natural prophylactic or antibiotic agent in aquaculture.


Assuntos
Antibacterianos/farmacologia , Organismos Aquáticos/microbiologia , Diatomáceas/química , Fenóis/farmacologia , Vibrio/efeitos dos fármacos , Animais , Antibacterianos/isolamento & purificação , Aquicultura , Bivalves/efeitos dos fármacos , Bivalves/microbiologia , Larva/efeitos dos fármacos , Larva/microbiologia , Fenóis/isolamento & purificação
17.
mBio ; 10(1)2019 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-30782660

RESUMO

Vibrio vulnificus, an opportunistic pathogen, is the causative agent of a life-threatening septicemia and a rising problem for aquaculture worldwide. The genetic factors that differentiate its clinical and environmental strains remain enigmatic. Furthermore, clinical strains have emerged from every clade of V. vulnificus In this work, we investigated the underlying genomic properties and population dynamics of the V. vulnificus species from an evolutionary and ecological point of view. Genome comparisons and bioinformatic analyses of 113 V. vulnificus isolates indicate that the population of V. vulnificus is made up of four different clusters. We found evidence that recombination and gene flow between the two largest clusters (cluster 1 [C1] and C2) have drastically decreased to the point where they are diverging independently. Pangenome and phenotypic analyses showed two markedly different lifestyles for these two clusters, indicating commensal (C2) and bloomer (C1) ecotypes, with differences in carbohydrate utilization, defense systems, and chemotaxis, among other characteristics. Nonetheless, we identified frequent intra- and interspecies exchange of mobile genetic elements (e.g., antibiotic resistance plasmids, novel "chromids," or two different and concurrent type VI secretion systems) that provide high levels of genetic diversity in the population. Surprisingly, we identified strains from both clusters in the mucosa of aquaculture species, indicating that manmade niches are bringing strains from the two clusters together. We propose an evolutionary model of V. vulnificus that could be broadly applicable to other pathogenic vibrios and facultative bacterial pathogens to pursue strategies to prevent their infections and emergence.IMPORTANCE Vibrio vulnificus is an emergent marine pathogen and is the cause of a deadly septicemia. However, the genetic factors that differentiate its clinical and environmental strains and its several biotypes remain mostly enigmatic. In this work, we investigated the underlying genomic properties and population dynamics of the V. vulnificus species to elucidate the traits that make these strains emerge as a human pathogen. The acquisition of different ecological determinants could have allowed the development of highly divergent clusters with different lifestyles within the same environment. However, we identified strains from both clusters in the mucosa of aquaculture species, indicating that manmade niches are bringing strains from the two clusters together, posing a potential risk of recombination and of emergence of novel variants. We propose a new evolutionary model that provides a perspective that could be broadly applicable to other pathogenic vibrios and facultative bacterial pathogens to pursue strategies to prevent their infections.


Assuntos
Ecótipo , Variação Genética , Genótipo , Vibrio vulnificus/classificação , Vibrio vulnificus/genética , Aquicultura , Organismos Aquáticos/microbiologia , Análise por Conglomerados , Biologia Computacional , Evolução Molecular , Fluxo Gênico , Transferência Genética Horizontal , Genoma Bacteriano , Fenótipo , Recombinação Genética , Vibrio vulnificus/isolamento & purificação , Vibrio vulnificus/fisiologia
18.
mBio ; 10(1)2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-30723123

RESUMO

Marine invertebrates often host diverse microbial communities, making it difficult to identify important symbionts and to understand how these communities are structured. This complexity has also made it challenging to assign microbial functions and to unravel the myriad of interactions among the microbiota. Here we propose to address these issues by applying evidence from model systems of host-microbe coevolution to complex marine invertebrate microbiomes. Coevolution is the reciprocal adaptation of one lineage in response to another and can occur through the interaction of a host and its beneficial symbiont. A classic indicator of coevolution is codivergence of host and microbe, and evidence of this is found in both corals and sponges. Metabolic collaboration between host and microbe is often linked to codivergence and appears likely in complex holobionts, where microbial symbionts can interact with host cells through production and degradation of metabolic compounds. Neutral models are also useful to distinguish selected microbes against a background population consisting predominately of random associates. Enhanced understanding of the interactions between marine invertebrates and their microbial communities is urgently required as coral reefs face unprecedented local and global pressures and as active restoration approaches, including manipulation of the microbiome, are proposed to improve the health and tolerance of reef species. On the basis of a detailed review of the literature, we propose three research criteria for examining coevolution in marine invertebrates: (i) identifying stochastic and deterministic components of the microbiome, (ii) assessing codivergence of host and microbe, and (iii) confirming the intimate association based on shared metabolic function.


Assuntos
Organismos Aquáticos/microbiologia , Evolução Biológica , Invertebrados/microbiologia , Microbiota , Animais
19.
BMC Bioinformatics ; 20(1): 53, 2019 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-30691412

RESUMO

BACKGROUND: Local similarity analysis (LSA) of time series data has been extensively used to investigate the dynamics of biological systems in a wide range of environments. Recently, a theoretical method was proposed to approximately calculate the statistical significance of local similarity (LS) scores. However, the method assumes that the time series data are independent identically distributed, which can be violated in many problems. RESULTS: In this paper, we develop a novel approach to accurately approximate statistical significance of LSA for dependent time series data using nonparametric kernel estimated long-run variance. We also investigate an alternative method for LSA statistical significance approximation by computing the local similarity score of the residuals based on a predefined statistical model. We show by simulations that both methods have controllable type I errors for dependent time series, while other approaches for statistical significance can be grossly oversized. We apply both methods to human and marine microbial datasets, where most of possible significant associations are captured and false positives are efficiently controlled. CONCLUSIONS: Our methods provide fast and effective approaches for evaluating statistical significance of dependent time series data with controllable type I error. They can be applied to a variety of time series data to reveal inherent relationships among the different factors.


Assuntos
Algoritmos , Modelos Estatísticos , Organismos Aquáticos/microbiologia , Bases de Dados como Assunto , Feminino , Humanos , Masculino , Microbiota , Fatores de Tempo
20.
Virus Genes ; 55(2): 218-226, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30627984

RESUMO

As an opportunist pathogen, Vibrio alginolyticus (V. alginolyticus), causes disease in marine animals. Bacterial contamination of seafood is not uncommon, and phage therapy is considered a safe way to decontaminate such foods to control the emergence of vibriosis. Here, we report on the isolation of a new, virulent phage called vB_ValP_IME271 (designated phage IME271), which infects V. alginolyticus and was isolated from seawater. Phage IME271 displayed good pH (7-9) and temperature tolerance (< 40 °C) and had a broad host range against Vibrio isolates, including 7 strains of V. alginolyticus and11 strains of V. parahaemolyticus. The IME271 genome was sequenced and annotated, the results of which showed that this phage is a Podoviridae family member with a genome length of 50,345 base pairs. The complete genome is double-stranded DNA with a G+C content of 41.4%. Encoded within the genome are 67 putative proteins, of which only 22 coding sequences have known functions, and no tRNAs are present. The BLASTn results for IME271 showed that it only shares similarity with the Vibrio phage VPp1 (sequence identity score of 96% over 87% of the genome) whose host is V. parahaemolyticus. Comparative analysis showed that IME271 and VPp1 share a similar genomic structure, and the structural proteins are highly similar (> 95% similarity score). In summary, our work identified a new lytic Podoviridae bacteriophage, which is infective to V. alginolyticus and V. parahaemolyticus. This bacteriophage could potentially be used to control V. alginolyticus and V. parahaemolyticus infections in marine animals.


Assuntos
Bacteriófagos/genética , Genômica , Podoviridae/genética , Vibrio alginolyticus/virologia , Organismos Aquáticos/microbiologia , Bacteriófagos/patogenicidade , Microbiologia de Alimentos , Genoma Viral/genética , Interações Hospedeiro-Patógeno/genética , Humanos , Podoviridae/patogenicidade , Alimentos Marinhos/microbiologia , Alimentos Marinhos/virologia , Água do Mar/virologia , Vibrioses/microbiologia , Vibrioses/virologia , Vibrio alginolyticus/genética , Vibrio alginolyticus/patogenicidade
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