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1.
J Aquat Anim Health ; 31(4): 320-327, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31743945

RESUMO

The aim of the present study was to characterize two gram-negative bacterial strains that were isolated from diseased Atlantic Horse Mackerel Trachurus trachurus in 2017. Based on the results obtained from the biochemical and chemotaxonomic characterization, the isolates were identified as Lacinutrix spp. The highest similarity of the 16S rRNA gene sequences was obtained with the strain L. venerupis CECT 8573T (99.1%), while other species showed similarities of 98% (L. jangbogonensis) and 97% (L. algicola and L. mariniflava). Molecular characterization by repetitive element (REP)-PCR and enterobacterial repetitive intergenic consensus (ERIC)-PCR, as well as proteomic characterization by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS), demonstrated heterogeneity between the strains from the Atlantic Horse Mackerel and the type strain, CECT 8573T . The virulence of one of the isolates for Turbot Scophthalmus maximus, European Sea Bass Dicentrarchus labrax, Senegalese Sole Solea senegalensis, and Rainbow Trout Oncorhynchus mykiss was assessed under experimental conditions. No mortalities were recorded after intraperitoneal injections with high doses of bacteria (1 × 109  CFU/mL). Thus, further studies are necessary to elucidate the impact of this bacterial species as a fish pathogen.


Assuntos
Doenças dos Peixes/microbiologia , Infecções por Flavobacteriaceae/veterinária , Flavobacteriaceae/isolamento & purificação , Flavobacteriaceae/patogenicidade , Perciformes/microbiologia , Animais , Peixes/microbiologia , Flavobacteriaceae/fisiologia , Infecções por Flavobacteriaceae/microbiologia , Injeções Intraperitoneais/veterinária , RNA Bacteriano/análise , RNA Ribossômico 16S/análise , Virulência
2.
J Microbiol ; 57(11): 982-990, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31659684

RESUMO

Microalgae and bacteria are known to be closely associated in diverse environments. To isolate dominant bacterial species associated with a green alga, Dunaliella tertiolecta, a photoreactor culture of the microalga was investigated using culture-based and culture-independent approaches. The bacterial community structure of the algal culture showed that the most abundant bacterial species under the culture conditions was related to the genus Winogradskyella. The closely related amplicon sequences, showing ≥ 99.5% 16S rRNA gene sequence similarity to one of the isolates, designated IMCC-33238T, constituted > 49% of the bacterial community and was therefore regarded as the most dominant species in the algal culture. Strain IMCC33238T was characterized by Gramstaining-negative and orange-colored rods. Phylogenetic analyses of the 16S rRNA genes as well as whole genome sequences revealed that strain IMCC33238T belonged to Winogradskyella and shared more than 97.2% 16S rRNA gene sequence similarity with Winogradskyella species. The strain contained iso-C15:1 G, iso-C15:0, iso-C15:0 3-OH, and summed feature 3 (C16:1ω6c and/or C16:1ω7c) as major fatty acids and MK-6 as the predominant quinone. The polar lipids found in strain IMCC33238T were phosphatidylethanolamine, two unidentified aminolipids, and three unidentified lipids. The genome of strain IMCC33238T was 3.37 Mbp in size with 33.9 mol% G + C content and proteorhodopsin. Many genes encoding folate and vitamin production are considered to play an important role in the bacteria-algae interaction. On the basis of phylogenetic and phenotypic characteristics, strain IMCC33238T represents a novel species in the genus Winogradskyella, for which the name Winogradskyella algicola sp. nov. is proposed. The type strain is IMCC33238T (= KACC 21192T = NBRC 113704T).


Assuntos
Clorofíceas/microbiologia , Flavobacteriaceae/classificação , Flavobacteriaceae/genética , Flavobacteriaceae/isolamento & purificação , Filogenia , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , Benzoquinonas/química , DNA Bacteriano/genética , Ácidos Graxos/química , Flavobacteriaceae/fisiologia , Fosfatidiletanolaminas/química , RNA Ribossômico 16S/genética , República da Coreia , Rodopsinas Microbianas/química , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química , Sequenciamento Completo do Genoma
3.
Oxid Med Cell Longev ; 2019: 6407524, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31641424

RESUMO

Most species of the genus Elizabethkingia are pathogenic to humans and animals, most commonly causing meningitis. However, our understanding of the pathogenic mechanisms involved is poor and there have been few pathological studies of Elizabethkingia spp. in animals. To understand the host injury induced by Elizabethkingia spp., we established a model of E. miricola infection in the black-spotted frog (Pelophylax nigromaculatus). The systematic pathology in and oxidative damage in the infection model were investigated. Our results show that recently isolated E. miricola is a bacterium that mainly parasitizes the host brain and that neurogenic organs are the predominant sites of damage. Infection mainly manifested as severe brain abscesses, meningoencephalitis, necrotic spondylitis, and necrotic retinitis. The liver, spleen, kidney, gastrointestinal tract, and lung were also affected to varying degrees, with bacterial necrotic inflammation. P. nigromaculatus also suffered enormous damage to its oxidative system during E. miricola infection, which may have further aggravated its disease state. Our results provide a preliminary reference for the study and treatment of Elizabethkingia spp.-induced neurological diseases in animals.


Assuntos
Infecções por Flavobacteriaceae/microbiologia , Infecções por Flavobacteriaceae/patologia , Flavobacteriaceae/fisiologia , Estresse Oxidativo , Ranidae/microbiologia , Animais , Antioxidantes/metabolismo , Modelos Animais de Doenças , Flavobacteriaceae/isolamento & purificação , Humanos , Modelos Biológicos , Especificidade de Órgãos , Filogenia
4.
Soft Matter ; 15(29): 6014-6026, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31309202

RESUMO

Growing demands for bio-friendly antifouling surfaces have stimulated the development of new and ever-improving material paradigms. Despite notable progress in bio-friendly coatings, the biofouling problem remains a critical challenge. In addition to biofouling characteristics, mechanically stressed surfaces such as ship hulls, piping systems, and heat exchangers require long-term durability in marine environments. Here, we introduce a new generation of anti-biofouling coatings with superior characteristics and high mechanical, chemical and environmental durability. In these surfaces, we have implemented the new physics of stress localization to minimize the adhesion of bio-species on the coatings. This polymeric material contains dispersed organogels in a high shear modulus matrix. Interfacial cavitation induced at the interface of bio-species and organogel particles leads to stress localization and detachment of bio-species from these surfaces with minimal shear stress. In a comprehensive study, the performance of these surfaces is assessed for both soft and hard biofouling including Ulva, bacteria, diatoms, barnacles and mussels, and is compared with that of state-of-the-art surfaces. These surfaces show Ulva accumulation of less than 1%, minimal bacterial biofilm growth, diatom attachment of 2%, barnacle adhesion of 0.02 MPa and mussel adhesion of 7.5 N. These surfaces promise a new physics-based route to address the biofouling problem and avoid adverse effects of biofouling on the environment and relevant technologies.


Assuntos
Incrustação Biológica , Estresse Mecânico , Animais , Aderência Bacteriana , Bivalves/fisiologia , Diatomáceas/fisiologia , Flavobacteriaceae/fisiologia , Propriedades de Superfície , Ulva/fisiologia
5.
Antonie Van Leeuwenhoek ; 112(8): 1263-1271, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30941530

RESUMO

A Gram-stain negative, rod-shaped and non-flagellated bacterium, designated strain 1Q3T, was isolated from coastal seawater in Xiamen Island, China, and subjected to taxonomic characterisation using a polyphasic approach. Strain 1Q3T was found to be aerobic, non-gliding and to lack flexirubin-type pigments. Catalase activity was found to be negative and oxidase positive. The strain has the ability to degrade protein. The nearly complete 16S rRNA gene sequence of strain 1Q3T shows high sequence similarities with Nonlabens aestuariivivens OITF-31T (96.1%), Nonlabens halophilus CAU 1131T and Nonlabens spongiae UST030701-156T (95.7% and 95.5%, respectively). Phylogenetic analysis based on 16S rRNA gene sequences and phylogenomic analysis based on a 92 bacterial core gene set indicated that strain 1Q3T should be affiliated to the genus Nonlabens, but forms a distinct monophyletic branch, which is separated from the other members within the genus Nonlabens. The predominant fatty acids (> 10%) were identified as iso-C17:0 3-OH, iso-C15:0 and anteiso-C15:0. The predominant respiratory quinone was found to be MK-6. The polar lipids were identified as phosphatidylethanolamine, a phospholipid, an aminolipid and three unidentified polar lipids. The draft genome size of strain 1Q3T is 3.7 Mb with genomic G + C content of 41.1 mol%. Based on these results, strain 1Q3T is concluded to represent a novel species within the genus Nonlabens, for which the name Nonlabens xiamenensis sp. nov. is proposed with the type strain 1Q3T (= MCCC 1A14023T = KCTC 62889T).


Assuntos
Flavobacteriaceae/classificação , Flavobacteriaceae/isolamento & purificação , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , China , Análise por Conglomerados , Citosol/química , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Ácidos Graxos/análise , Flavobacteriaceae/genética , Flavobacteriaceae/fisiologia , Fosfolipídeos/análise , Filogenia , Quinonas/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
6.
Appl Environ Microbiol ; 85(7)2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30737345

RESUMO

Plankton communities consist of complex microbial consortia that change over time. These fluctuations can be only partially explained by limiting resources. Biotic factors such as herbivores and pathogens also contribute to the control of algal blooms. Here we address the effects of algicidal bacteria on a natural plankton community in an indoor enclosure experiment. The algicidal bacteria, introduced into plankton taken directly from the North Sea during a diatom bloom, caused the rapid decline of the bloom-forming Chaetoceros socialis within only 1 day. The haptophyte Phaeocystis, in contrast, is resistant to the lytic bacteria and could benefit from the removal of the competitor, as indicated by an onset of a bloom in the treated enclosures. This cascading effect caused by the bacterial pathogen accelerated the succession of Phaeocystis, which bloomed with a delay of only several weeks in the in situ waters at Helgoland Roads in the North Sea. The algicidal bacteria can thus modulate the community within the limits of the abiotic and biotic conditions of the local environment. Implications of our findings for plankton ecosystem functioning are discussed.IMPORTANCE Plankton communities change on a seasonal basis in temperate systems, with distinct succession patterns; this is mainly due to algal species that have their optimal timing relative to environmental conditions. We know that bacterial populations are also instrumental in the decay and termination of phytoplankton blooms. Here, we describe algicidal bacteria as modulators of this important species succession. Upon treatment of a natural plankton consortium with an algicidal bacterium, we observed a strong shift in the phytoplankton community structure, compared to controls, resulting in formation of a succeeding Phaeocystis bloom. Blooms of this alga have a substantial impact on global biogeochemical and ecological cycles, as they are responsible for a substantial proportion of primary production during spring in the North Sea. We propose that one of the key factors influencing such community shifts may be algicidal bacteria.


Assuntos
Antibiose , Flavobacteriaceae/crescimento & desenvolvimento , Flavobacteriaceae/fisiologia , Plâncton/crescimento & desenvolvimento , Água do Mar/microbiologia , Diatomáceas/efeitos dos fármacos , Diatomáceas/crescimento & desenvolvimento , Ecossistema , Eutrofização/efeitos dos fármacos , Biologia Marinha , Mar do Norte , Controle Biológico de Vetores , Fitoplâncton/efeitos dos fármacos , Dinâmica Populacional , Estações do Ano
7.
FEMS Microbiol Ecol ; 95(3)2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30689834

RESUMO

Interactions between photoautotrophs and heterotrophs are central to marine microbial ecosystems. Synechococcus are dominant marine phototrophs, and they are frequently associated with heterotrophic bacteria. These co-cultures provide a useful research system to investigate photoautotroph-heterotroph interactions in marine systems. Bacteria within the Roseobacter clade and Flavobacteria are two of the main bacterial lineages that exhibit intimate associations with Synechococcus populations. We conducted metagenomic analyses of a Synechococcus culture, followed by genomic binning of metagenomic contigs, and recovered five nearly complete genomes, including members of the Roseobacter clade (i.e. Marivita sp. XM-24) and Flavobacteria (i.e. Fluviicola sp. XM-24). Marivita sp. XM-24 is an ecological generalist of the Roseobacter clade and displays diverse metabolic capacities for the acquisition of nutrients and energy sources. Specifically, the genome contained numerous gene complements involved in the uptake and metabolism of nitrogen- and phosphorus-containing inorganic and organic compounds, in addition to the potential for aerobic anoxygenic photosynthesis, oxidation of carbon monoxide, inorganic sulfur oxidation, DMSP demethylation and PHA metabolism. The genome of the Flavobacteria representative, Fluviicola sp. XM-24, contained numerous peptidases, glycoside hydrolases, adhesion-related proteins and genes involved in gliding motility. Fluviicola sp. XM-24 likely specialize in the degradation of high molecular weight compound exudates from Synechococcus cells, including polysaccharides and polypeptides via attachment to particles, surfaces or cells. The distinct metabolic strategies identified within several heterotrophic bacteria that are associated with Syneochococcus cells provide insights into their lifestyles and nutrient utilization patterns, in addition to their interactions with photoautotrophs. Biological interactions, including mutualism, competition and antagonism, shape the microbial community structure of marine environments and are critical for understanding biogeochemical cycling in the ocean. These results provide valuable insights into the nature of interactions between dominant marine photoautotrophs and associated bacterial heterotrophs.


Assuntos
Estuários , Processos Heterotróficos/fisiologia , Água do Mar/microbiologia , Synechococcus/fisiologia , Flavobacteriaceae/classificação , Flavobacteriaceae/genética , Flavobacteriaceae/metabolismo , Flavobacteriaceae/fisiologia , Genômica , Processos Heterotróficos/genética , Redes e Vias Metabólicas/genética , Interações Microbianas , Microbiota/genética , Roseobacter/classificação , Roseobacter/genética , Roseobacter/metabolismo , Roseobacter/fisiologia , Synechococcus/genética
8.
Environ Microbiol ; 21(2): 648-666, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30565818

RESUMO

The taxonomy of marine and non-marine organisms rarely overlap, but the mechanisms underlying this distinction are often unknown. Here, we predicted three major ocean-to-land transitions in the evolutionary history of Flavobacteriaceae, a family known for polysaccharide and peptide degradation. These unidirectional transitions were associated with repeated losses of marine signature genes and repeated gains of non-marine adaptive genes. This included various Na+ -dependent transporters, osmolyte transporters and glycoside hydrolases (GH) for sulfated polysaccharide utilization in marine descendants, and in non-marine descendants genes for utilizing the land plant material pectin and genes facilitating terrestrial host interactions. The K+ scavenging ATPase was repeatedly gained whereas the corresponding low-affinity transporter repeatedly lost upon transitions, reflecting K+ ions are less available to non-marine bacteria. Strikingly, the central metabolism Na+ -translocating NADH: quinone dehydrogenase gene was repeatedly gained in marine descendants, whereas the H+ -translocating counterpart was repeatedly gained in non-marine lineages. Furthermore, GH genes were depleted in isolates colonizing animal hosts but abundant in bacteria inhabiting other non-marine niches; thus relative abundances of GH versus peptidase genes among Flavobacteriaceae lineages were inconsistent with the marine versus non-marine dichotomy. We suggest that phylogenomic analyses can cast novel light on mechanisms explaining the distribution and ecology of key microbiome components.


Assuntos
Evolução Biológica , Ecossistema , Flavobacteriaceae/genética , Adaptação Fisiológica , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Flavobacteriaceae/classificação , Flavobacteriaceae/enzimologia , Flavobacteriaceae/fisiologia , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Pectinas/metabolismo , Filogenia , Polissacarídeos/metabolismo
9.
BMC Genomics ; 19(1): 842, 2018 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-30482156

RESUMO

BACKGROUND: Pyropia yezoensis is an important marine crop which, due to its high protein content, is widely used as a seafood in China. Unfortunately, red rot disease, caused by Pythium porphyrae, seriously damages P. yezoensis farms every year in China, Japan, and Korea. Proteomic methods are often used to study the interactions between hosts and pathogens. Therefore, an iTRAQ-based proteomic analysis was used to identify pathogen-responsive proteins following the artificial infection of P. yezoensis with P. porphyrae spores. RESULTS: A total of 762 differentially expressed proteins were identified, of which 378 were up-regulated and 384 were down-regulated following infection. A large amount of these proteins were involved in disease stress, carbohydrate metabolism, cell signaling, chaperone activity, photosynthesis, and energy metabolism, as annotated in the KEGG database. Overall, the data showed that P. yezoensis resists infection by inhibiting photosynthesis, and energy and carbohydrate metabolism pathways, as supported by changes in the expression levels of related proteins. The expression data are available via ProteomeXchange with the identifier PXD009363. CONCLUSIONS: The current data provide an overall summary of the red algae responses to pathogen infection. This study improves our understanding of infection resistance in P. yezoensis, and may help in increasing the breeding of P. porphyrae-infection tolerant macroalgae.


Assuntos
Proteínas de Algas/análise , Flavobacteriaceae/fisiologia , Doenças das Plantas/microbiologia , Proteômica/métodos , Rodófitas/metabolismo , Espectrometria de Massas em Tandem/métodos , Proteínas de Algas/metabolismo , Rodófitas/microbiologia
10.
J Microbiol ; 56(12): 868-873, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30361977

RESUMO

A yellow pigmented bacterium designated strain MBLN094T within the family Flavobacteriaceae was isolated from a halophyte Salicornia europaea on the coast of the Yellow Sea. This strain was a Gram-stain negative, aerobic, non-spore forming, rod-shaped bacterium. Phylogenetic analysis of the 16S rRNA gene sequence of strain MBLN094T was found to be related to the genus Zunongwangia, exhibiting 16S rRNA gene sequence similarity values of 97.0, 96.8, 96.4, and 96.3% to Zunongwangia mangrovi P2E16T, Z. profunda SM-A87T, Z. atlantica 22II14-10F7T, and Z. endophytica CPA58T, respectively. Strain MBLN094T grew at 20‒37°C (optimum, 25‒30°C), at pH 6.0‒10.0 (optimum, 7.0‒8.0), and with 0.5‒15.0% (w/v) NaCl (optimum, 2.0‒5.0%). Menaquinone MK-6 was the sole respiratory quinone. The polar lipids were phosphatidylethanolamine, two unidentified aminolipids, and four unidentified lipids. Major fatty acids were iso-C17:0 3-OH, summed feature 3 (C16:1ω6c and/or C16:1 ω7c), and iso-C15:0. The genomic DNA G + C content was 37.4 mol%. Based on these polyphasic taxonomic data, strain MBLN094T is considered to represent a novel species of the genus Zunongwangia, for which the name Zunongwangia flava sp. nov. is proposed. The type strain is MBLN094T (= KCTC 62279T = JCM 32262T).


Assuntos
Chenopodiaceae/microbiologia , Flavobacteriaceae/classificação , Flavobacteriaceae/isolamento & purificação , Filogenia , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/análise , Flavobacteriaceae/genética , Flavobacteriaceae/fisiologia , Fosfatidiletanolaminas , RNA Ribossômico 16S/genética , República da Coreia , Análise de Sequência de DNA , Especificidade da Espécie , Vitamina K 2/análogos & derivados , Vitamina K 2/análise , Microbiologia da Água
11.
J Microbiol ; 56(9): 614-618, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30141155

RESUMO

A Gram-negative, non-motile, aerobic bacterium, designated strain IP7T, was isolated from seawater at the shore of the Incheon Eulwang-ri beach, South Korea. Cells of strain IP7T are straight or slightly rod-shaped and colonies are round, convex and orange-yellow. Strain IP7T is flexirubin-negative, mild halophile, catalase-and oxidase-positive, and produces a yellow-orange carotenoid pigment. Growth is optimal at 30°C, pH 7-9, and 2.0-4.0% NaCl (w/v). On the basis of 16S rRNA gene sequence similarity, strain IP7T is affiliated with genus Aestuariibaculum in the family Flavobacteriaceae, the closest relative being Aestuariibaculum suncheonense SC17T (98.3% sequence similarity). The DNA G + C content of the novel strain is 37.4 mol%. The only quinone is MK-6 menaquinone. Iso-branched C15:0, iso-branched C15:1 G, and iso-branched C17:0 3-OH are major fatty acids. The major polar lipids are phosphatidylethanolamine, an unidentified aminoglycolipid and two unidentified glycolipids. The DNA-DNA hybridization value of strain IP7T with Aestuariibaculum suncheonense SC17T is 28.87%. Based on the collective DNA-DNA hybridization, biochemical, phylogenetic and physiological data, we report a novel species of the genus Aestuariibaculum for which the name Aestuariibaculum marinum sp. nov. is proposed. The type strain is IP7T (= KCTC 52521T = JCM 31725T).


Assuntos
Flavobacteriaceae/classificação , Flavobacteriaceae/isolamento & purificação , Filogenia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano , Ácidos Graxos/análise , Flavobacteriaceae/genética , Flavobacteriaceae/fisiologia , Hibridização de Ácido Nucleico , Fosfatidiletanolaminas/análise , Pigmentação , RNA Ribossômico 16S/genética , República da Coreia , Água do Mar/microbiologia , Especificidade da Espécie , Vitamina K 2/análogos & derivados
12.
Artigo em Inglês | MEDLINE | ID: mdl-30094005

RESUMO

Background: Myroides spp. are common environmental organisms and they can be isolated predominantly in water, soil, food and in sewage treatment plants. In the last two decades, an increasing number of infections such as urinary tract infections and skin and soft tissue infections, caused by these microorganisms has been reported. Selection of appropriate antibiotic therapy to treat the infections caused by Myroides spp. is difficult due to the production of a biofilm and the organism's intrinsic resistance to many antibiotic classes. Case presentation: We report the case of a 69-year-old immunocompromised patient who presented with repeated episodes of macroscopic haematuria, from Northern Italy.A midstream urine sample cultured a Gram negative rod in significant amounts (> 105 colony-forming units (cfu)/mL), which was identified as Myroides odoratimimus. The patient was successfully treated with trimethoprim/sulfamethoxazole after antibiotic susceptibility testing confirmed its activity. Conclusion: This case underlines the emergence of multidrug resistant Myroides spp. which are ubiquitous in the environment and it demands that clinicians should be more mindful about the role played by atypical pathogens, which may harbour or express multidrug resistant characteristics, in immunocompromised patients or where there is a failure of empiric antimicrobial therapy.


Assuntos
Antibacterianos/administração & dosagem , Farmacorresistência Bacteriana Múltipla , Infecções por Flavobacteriaceae/microbiologia , Flavobacteriaceae/efeitos dos fármacos , Flavobacteriaceae/isolamento & purificação , Infecções Urinárias/microbiologia , Idoso , Flavobacteriaceae/genética , Flavobacteriaceae/fisiologia , Infecções por Flavobacteriaceae/tratamento farmacológico , Infecções por Flavobacteriaceae/imunologia , Humanos , Hospedeiro Imunocomprometido , Masculino , Testes de Sensibilidade Microbiana , Sulfametoxazol/administração & dosagem , Trimetoprima/administração & dosagem , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/imunologia
13.
ISME J ; 12(12): 2894-2906, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30061707

RESUMO

Polysaccharide degradation by heterotrophic microbes is a key process within Earth's carbon cycle. Here, we use environmental proteomics and metagenomics in combination with cultivation experiments and biochemical characterizations to investigate the molecular details of in situ polysaccharide degradation mechanisms during microalgal blooms. For this, we use laminarin as a model polysaccharide. Laminarin is a ubiquitous marine storage polymer of marine microalgae and is particularly abundant during phytoplankton blooms. In this study, we show that highly specialized bacterial strains of the Bacteroidetes phylum repeatedly reached high abundances during North Sea algal blooms and dominated laminarin turnover. These genomically streamlined bacteria of the genus Formosa have an expanded set of laminarin hydrolases and transporters that belonged to the most abundant proteins in the environmental samples. In vitro experiments with cultured isolates allowed us to determine the functions of in situ expressed key enzymes and to confirm their role in laminarin utilization. It is shown that laminarin consumption of Formosa spp. is paralleled by enhanced uptake of diatom-derived peptides. This study reveals that genome reduction, enzyme fusions, transporters, and enzyme expansion as well as a tight coupling of carbon and nitrogen metabolism provide the tools, which make Formosa spp. so competitive during microalgal blooms.


Assuntos
Bacteroidetes/fisiologia , Eutrofização , Flavobacteriaceae/fisiologia , Glucanos/metabolismo , Microalgas/microbiologia , Polissacarídeos/metabolismo , Adaptação Fisiológica , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Bacteroidetes/genética , Ciclo do Carbono , Flavobacteriaceae/genética , Hidrolases/genética , Hidrolases/metabolismo , Metagenômica , Microalgas/metabolismo , Mar do Norte , Fitoplâncton/metabolismo , Fitoplâncton/microbiologia
14.
PLoS One ; 13(7): e0200731, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30024943

RESUMO

We report the isolation and characterization of two Elizabethkingia anophelis strains (OSUVM-1 and OSUVM-2) isolated from sources associated with horses in Oklahoma. Both strains appeared susceptible to fluoroquinolones and demonstrated high MICs to all cell wall active antimicrobials including vancomycin, along with aminoglycosides, fusidic acid, chloramphenicol, and tetracycline. Typical of the Elizabethkingia, both draft genomes contained multiple copies of ß-lactamase genes as well as genes predicted to function in antimicrobial efflux. Phylogenetic analysis of the draft genomes revealed that OSUVM-1 and OSUVM-2 differ by only 6 SNPs and are in a clade with 3 strains of Elizabethkingia anophelis that were responsible for human infections. These findings therefore raise the possibility that Elizabethkingia might have the potential to move between humans and animals in a manner similar to known zoonotic pathogens.


Assuntos
Flavobacteriaceae/genética , Genes Bacterianos/genética , Variação Genética , Genoma Bacteriano/genética , Animais , Antibacterianos/farmacologia , Flavobacteriaceae/classificação , Flavobacteriaceae/fisiologia , Infecções por Flavobacteriaceae/microbiologia , Infecções por Flavobacteriaceae/veterinária , Doenças dos Cavalos/microbiologia , Cavalos , Especificidade de Hospedeiro , Humanos , Testes de Sensibilidade Microbiana , Filogenia , Análise de Sequência de DNA , Especificidade da Espécie
15.
Environ Microbiol Rep ; 10(4): 433-443, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29707906

RESUMO

Sponges interact with diverse and rich communities of bacteria that are phylogenetically often distinct from their free-living counterparts. Recent genomics and metagenomic studies have indicated that bacterial sponge symbionts also have distinct functional features from free-living bacteria; however, it is unclear, if such genome-derived functional signatures are common and present in different symbiont taxa. We therefore compared here a large set of genomes from cultured (Pseudovibrio, Ruegeria and Aquimarina) and yet-uncultivated (Synechococcus) bacteria found in either sponge-associated or free-living sources. Our analysis revealed only very few genera-specific functions that could be correlated with a sponge-associated lifestyle. Using different sets of sponge-associated and free-living bacteria for each genus, we could however show that the functions identified as 'sponge-associated' are dependent on the reference comparison being made. Using simulation approaches, we show how this influences the robustness of identifying functional signatures and how evolutionary divergence and genomic adaptation can be distinguished. Our results highlight the future need for robust comparative analyses to define genomic signatures of symbiotic lifestyles, whether it is for symbionts of sponges or other host organisms.


Assuntos
Bactérias/genética , Fenômenos Fisiológicos Bacterianos , Genoma Bacteriano/genética , Poríferos/microbiologia , Poríferos/fisiologia , Simbiose , Adaptação Biológica , Animais , Bases de Dados Genéticas , Flavobacteriaceae/genética , Flavobacteriaceae/fisiologia , Redes e Vias Metabólicas/genética , Rhodobacteraceae/genética , Rhodobacteraceae/fisiologia , Análise de Sequência de DNA , Synechococcus/genética , Synechococcus/fisiologia
16.
Curr Microbiol ; 75(9): 1142-1146, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29696370

RESUMO

The Gram-stain-negative, rod-shaped, aerobic strain, designated YC1039T, was isolated from a seamount northern Mariana Trench in the tropical western Pacific. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain YC1039T was related to the genus Mesoflavibacter and had highest 16S rRNA gene sequence similarities to Mesoflavibacter sabulilitoris GJMS-9T (98.3%) and Mesoflavibacter zeaxanthinifaciens TD-ZX30T (98.2%). The predominant cellular fatty acids were iso-C15:1 G and iso-C15:0. The polar lipid profile contained phosphatidylethanolamine, two unidentified phospholipids, and 13 unidentified lipids. The respiratory quinone was MK-6. The genomic DNA G+C content of strain YC1039T was 29.8 mol%. On the basis of the evidence presented in this study, strain YC1039T represents a novel species of the genus Mesoflavibacter, for which we propose the name Mesoflavibacter profundi sp. nov. (type strain YC1039T = KACC 19026T = CGMCC 1.16329T).


Assuntos
Flavobacteriaceae/classificação , Flavobacteriaceae/fisiologia , Filogenia , Água do Mar/microbiologia , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/análise , Flavobacteriaceae/genética , Genótipo , Oceano Pacífico , Fenótipo , Fosfolipídeos/análise , RNA Ribossômico 16S/genética , Vitamina K 2
17.
ISME J ; 12(6): 1605-1618, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29568113

RESUMO

Phage-host interactions are critical to ecology, evolution, and biotechnology. Central to those is infection efficiency, which remains poorly understood, particularly in nature. Here we apply genome-wide transcriptomics and proteomics to investigate infection efficiency in nature's own experiment: two nearly identical (genetically and physiologically) Bacteroidetes bacterial strains (host18 and host38) that are genetically intractable, but environmentally important, where phage infection efficiency varies. On host18, specialist phage phi18:3 infects efficiently, whereas generalist phi38:1 infects inefficiently. On host38, only phi38:1 infects, and efficiently. Overall, phi18:3 globally repressed host18's transcriptome and proteome, expressed genes that likely evaded host restriction/modification (R/M) defenses and controlled its metabolism, and synchronized phage transcription with translation. In contrast, phi38:1 failed to repress host18's transcriptome and proteome, did not evade host R/M defenses or express genes for metabolism control, did not synchronize transcripts with proteins and its protein abundances were likely targeted by host proteases. However, on host38, phi38:1 globally repressed host transcriptome and proteome, synchronized phage transcription with translation, and infected host38 efficiently. Together these findings reveal multiple infection inefficiencies. While this contrasts the single mechanisms often revealed in laboratory mutant studies, it likely better reflects the phage-host interaction dynamics that occur in nature.


Assuntos
Bacteriófagos/genética , Bacteriófagos/fisiologia , Bacteroidetes/virologia , Proteoma/genética , Transcriptoma , Bacteroidetes/fisiologia , Flavobacteriaceae/fisiologia , Flavobacteriaceae/virologia , Genômica , Metabolômica , Mutação , Biossíntese de Proteínas , Proteômica , Análise de Sequência de RNA , Transcrição Genética
18.
Antonie Van Leeuwenhoek ; 111(9): 1687-1695, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29502262

RESUMO

An aerobic, Gram-stain negative, rod-shaped, non-motile bacterium, designated as strain HQA918T, was isolated from an ascidian, Botryllus schlosseri, which was collected from the coast of Weihai in the north of the Yellow Sea, in China. The strain grew optimally at 28-30 °C, at pH values 7.0-8.0, and in the presence of 1.0-3.0% (w/v) sodium chloride (NaCl). A phylogenetic analysis based on 16S rRNA gene sequences showed that strain HQA918T can be affiliated with the family Flavobacteriaceae in the phylum Bacteroidetes, with 92.7% similarity to its close relatives. The major fatty acids identified were iso-C15:0, iso-C15:0 3-OH, and summed feature 3 (iso-C15:0 2-OH and/or C16:1ω7c). The major polar lipids were phosphatidylethanolamine, one unidentified aminolipid, and five unidentified polar lipids. The G+C content of the genomic DNA was 44.1 mol%. On the basis of the phylogenetic, genotypic, phenotypic, and chemotaxonomic data, this organism should be classified as a representative of a novel genus, for which the name Ascidiaceibacter gen. nov. is proposed. The type species is Ascidiaceibacter salegens sp. nov. (type strain HQA918T = KCTC 52719T = MCCC 1K03259T).


Assuntos
Flavobacteriaceae/classificação , Flavobacteriaceae/fisiologia , Filogenia , Água do Mar/microbiologia , Urocordados/microbiologia , Animais , Bacteroidetes/genética , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Flavobacteriaceae/química , Flavobacteriaceae/genética , Genoma Bacteriano , Fosfatidiletanolaminas/química , RNA Ribossômico 16S/genética , Tolerância ao Sal , Especificidade da Espécie , Áreas Alagadas
19.
J Fish Dis ; 41(5): 829-845, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29542826

RESUMO

Flavobacterial diseases are significant impediments to hatchery-based fishery conservation and aquaculture productivity worldwide. Recent studies revealed a multitude of novel flavobacteria within the reproductive fluids and unfertilized eggs of feral Chinook salmon Oncorhynchus tshawytscha broodstock, some of which were associated with systemic disease. Herein, embryonated eggs/fry from these broodstock were assayed for flavobacteria while in incubator stacks in three hatcheries over 2 years, as was the water entering hatchery incubators. Overall, >65% of sampled eggs and 38% of fry were colonized by flavobacteria. One hundred and ninety-one egg and fry-associated flavobacterial isolates were characterized phenotypically and via 16S rRNA gene sequencing and phylogenetic analyses, revealing that the majority fell into 22 clades (i.e., 15 Flavobacterium spp. groups and seven Chryseobacterium spp. groups) that varied in presence by facility. Although some matched previously described fish-pathogenic species, the majority were distinct from all described flavobacteria and likely represent novel species. Of concern, iodophor disinfection at the commonly utilized dose/duration for egg-surface disinfection did not eliminate flavobacteria. Results also implicated maternal routes of infection and source water for some flavobacteria. In total, study findings underscore the complexity of flavobacterial ecology within hatchery environments and highlight the need for improved hatchery biosecurity practices.


Assuntos
Desinfecção , Doenças dos Peixes/epidemiologia , Infecções por Flavobacteriaceae/veterinária , Flavobacteriaceae/classificação , Salmão , Microbiologia da Água , Animais , Desinfetantes/administração & dosagem , Doenças dos Peixes/microbiologia , Flavobacteriaceae/genética , Flavobacteriaceae/fisiologia , Infecções por Flavobacteriaceae/epidemiologia , Infecções por Flavobacteriaceae/microbiologia , Iodóforos/administração & dosagem , Michigan/epidemiologia , Óvulo/microbiologia , Prevalência
20.
Braz. j. microbiol ; 49(1): 97-103, Jan.-Mar. 2018. graf
Artigo em Inglês | LILACS | ID: biblio-889210

RESUMO

ABSTRACT Freezing temperatures are a major challenge for life at the poles. Decreased membrane fluidity, uninvited secondary structure formation in nucleic acids, and protein cold-denaturation all occur at cold temperatures. Organisms adapted to polar regions possess distinct mechanisms that enable them to survive in extremely cold environments. Among the cold-induced proteins, cold shock protein (Csp) family proteins are the most prominent. A gene coding for a Csp-family protein, cspB, was cloned from an arctic bacterium, Polaribacter irgensii KOPRI 22228, and overexpression of cspB greatly increased the freeze-survival rates of Escherichia coli hosts, to a greater level than any previously reported Csp. It also suppressed the cold-sensitivity of an E. coli csp-quadruple deletion strain, BX04. Sequence analysis showed that this protein consists of a unique domain at its N-terminal end and a well conserved cold shock domain at its C-terminal end. The most common mechanism of Csp function in cold adaption is melting of the secondary structures in RNA and DNA molecules, thus facilitating transcription and translation at low temperatures. P. irgensii CspB bound to oligo(dT)-cellulose resins, suggesting single-stranded nucleic acid-binding activity. The unprecedented level of freeze-tolerance conferred by P. irgensii CspB suggests a crucial role for this protein in survival in polar environments.


Assuntos
Proteínas de Bactérias/metabolismo , Flavobacteriaceae/fisiologia , Proteínas e Peptídeos de Choque Frio/metabolismo , Regiões Árticas , Proteínas de Bactérias/genética , Regulação Bacteriana da Expressão Gênica , Temperatura Baixa , Ecossistema , Flavobacteriaceae/isolamento & purificação , Flavobacteriaceae/genética , Proteínas e Peptídeos de Choque Frio/genética
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