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1.
Int J Syst Evol Microbiol ; 70(11): 5899-5910, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33016860

RESUMO

A novel bacterial strain, designated CSW-10T, isolated from a freshwater pond in Taiwan, was characterized using a polyphasic taxonomic approach. Cells were Gram-stain-negative, aerobic, non-motile, rod-shaped and formed yellow-coloured colonies. Optimal growth occurred at 30 °C, pH 7, and in the absence of NaCl. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that strain CSW-10T formed a phylogenetic lineage in the genus Sphingomonas. The 16S rRNA gene sequence similarity indicated that strain CSW-10T was most closely related to Sphingomonas fonticola TNR-2T (97.6%). Strain CSW-10T showed 69.8-70.7% average nucleotide identity and 19.0-23.0% digital DNA-DNA hybridization identity with the strains of other related Sphingomonas species. The major fatty acids of strain CSW-10T were summed feature 8 (C18:1 ω7c and/or C18:1 ω6c) and C17:1 ω6c. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidyldimethylethanolamine, phosphatidylcholine, one uncharacterized sphingoglycolipid, five uncharacterized aminophospholipids, one uncharacterized phospholipid and one uncharacterized lipid. The predominant polyamines were homospermidine and spermidine. The major isoprenoid quinone was Q-10. Genomic DNA G+C content of strain CSW-10T was 62.0 mol%. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain CSW-10T should represent a novel species of the genus Sphingomonas, for which the name Sphingomonas lacunae sp. nov. is proposed. The type strain is CSW-10T (=BCRC 81190T =LMG 31340T).


Assuntos
Filogenia , Tanques/microbiologia , Sphingomonas/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Água Doce/microbiologia , Hibridização de Ácido Nucleico , Fosfolipídeos/química , Pigmentação , Poliaminas/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Espermidina/química , Sphingomonas/isolamento & purificação , Taiwan , Ubiquinona/análogos & derivados , Ubiquinona/química
2.
Exp Parasitol ; 218: 107985, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32918877

RESUMO

Acanthamoeba castellanii is a protist that has a high predation efficiency for bacteria in a number of monoxenic culture experiments. However, the role of A. castellanii in the microbial community is still unknown because of the lack of studies on multiple-species interactions. The aim of this study was to investigate the change of bacterial composition after A. castellanii emerges in a water environment. We added A. castellanii to an environmental water sample and incubated it for two days. Then, we performed 16S ribosomal RNA sequencing techniques to analyze the changes in bacterial composition. In this study, A. castellanii slightly increased the relative abundance of a few opportunistic pathogens, such as Legionella, Roseomonas, and Haemophilus. This result may be related to the training ground hypothesis. On the other hand, the growth of some bacteria was inhibited, such as Cyanobacteria and Firmicutes. Although A. castellanii did not drastically change the whole bacterial community, we surprisingly found the dissolved oxygen concentration was increased after incubation with A. castellanii. We applied environmental water at the laboratory scale to investigate the interactions among A. castellanii, complex microbial communities and the environment. We identified the bacteria that are sensitive to A. castellanii and further found the novel relationship between dissolved oxygen and microbial interaction. Our results helped to clarify the role of A. castellanii in microbial communities.


Assuntos
Acanthamoeba castellanii/fisiologia , Bdellovibrio/isolamento & purificação , Legionella/isolamento & purificação , Microbiota/fisiologia , Oxigênio/metabolismo , Acanthamoeba castellanii/genética , Bdellovibrio/genética , Bdellovibrio/fisiologia , DNA/isolamento & purificação , Legionella/genética , Legionella/patogenicidade , Legionella/fisiologia , Tanques/microbiologia , Tanques/parasitologia , RNA Ribossômico 16S/química , Reação em Cadeia da Polimerase em Tempo Real , Reprodutibilidade dos Testes , Virulência
3.
Appl Environ Microbiol ; 86(20)2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32769196

RESUMO

As climate change continues to stress freshwater resources, we have a pressing need to identify alternative (nontraditional) sources of microbially safe water for irrigation of fresh produce. This study is part of the center CONSERVE, which aims to facilitate the adoption of adequate agricultural water sources. A 26-month longitudinal study was conducted at 11 sites to assess the prevalence of bacteria indicating water quality, fecal contamination, and crop contamination risk (Escherichia coli, total coliforms [TC], Enterococcus, and Aeromonas). Sites included nontidal freshwater rivers/creeks (NF), a tidal brackish river (TB), irrigation ponds (PW), and reclaimed water sites (RW). Water samples were filtered for bacterial quantification. E. coli, TC, enterococci (∼86%, 98%, and 90% positive, respectively; n = 333), and Aeromonas (∼98% positive; n = 133) were widespread in water samples tested. Highest E. coli counts were in rivers, TC counts in TB, and enterococci in rivers and ponds (P < 0.001 in all cases) compared to other water types. Aeromonas counts were consistent across sites. Seasonal dynamics were detected in NF and PW samples only. E. coli counts were higher in the vegetable crop-growing (May-October) than nongrowing (November-April) season in all water types (P < 0.05). Only one RW and both PW sites met the U.S. Food Safety Modernization Act water standards. However, implementation of recommended mitigation measures of allowing time for microbial die-off between irrigation and harvest would bring all other sites into compliance within 2 days. This study provides comprehensive microbial data on alternative irrigation water and serves as an important resource for food safety planning and policy setting.IMPORTANCE Increasing demands for fresh fruit and vegetables, a variable climate affecting agricultural water availability, and microbial food safety goals are pressing the need to identify new, safe, alternative sources of irrigation water. Our study generated microbial data collected over a 2-year period from potential sources of irrigation (rivers, ponds, and reclaimed water sites). Pond water was found to comply with Food Safety Modernization Act (FSMA) microbial standards for irrigation of fruit and vegetables. Bacterial counts in reclaimed water, a resource that is not universally allowed on fresh produce in the United States, generally met microbial standards or needed minimal mitigation. We detected the most seasonality and the highest microbial loads in river water, which emerged as the water type that would require the most mitigation to be compliant with established FSMA standards. This data set represents one of the most comprehensive, longitudinal analyses of alternative irrigation water sources in the United States.


Assuntos
Aeromonas/isolamento & purificação , Irrigação Agrícola , Enterococcus/isolamento & purificação , Escherichia coli/isolamento & purificação , Tanques/microbiologia , Rios/microbiologia , Irrigação Agrícola/métodos , Delaware , Estudos Longitudinais , Maryland , Microbiologia da Água
4.
Int J Syst Evol Microbiol ; 70(9): 5075-5086, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32790604

RESUMO

Bacterial strain NST-5T, isolated from a fish pond in Taiwan, was characterized using a polyphasic taxonomy approach. Results of phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that strain NST-5T formed a phylogenetic lineage in the genus Flavobacterium. Analysis of 16S rRNA gene sequences showed that strain NST-5T showed the highest similarity to Flavobacterium enshiense DK69T (94.9 %), Flavobacterium ahnfeltiae 10Alg 130T (94.8 %) and Flavobacterium vireti THG-SM1T (94.8 %). Strain NST-5T showed 68.9-72.5% average nucleotide identity and 19.1-23.7% digital DNA-DNA hybridization identity with the type strains of other close related Flavobacterium species. Cells of the strain were Gram-stain-negative, strictly aerobic, motile by gliding, rod-shaped and formed yellow colonies. Optimal growth occurred at 30 °C, pH 7 and with 0.5% NaCl. Strain NST-5T contained iso-C15:0, C15:0 and iso-C16:0 as the predominant fatty acids. The major hydroxyl fatty acids were iso-C16:0 3-OH and iso-C17:0 3-OH. The polar lipid profile consisted of phosphatidylethanolamine, three uncharacterized aminophospholipids, two uncharacterized phospholipids and one uncharacterized aminolipid. The major polyamine was homospermidine. The major isoprenoid quinone was MK-6. The DNA G+C content of the genomic DNA was 35.5 mol%. Differential phenotypic properties, together with the phylogenetic inference, demonstrate that strain NST-5T should be classified as a novel species of the genus Flavobacterium, for which the name Flavobacterium ichthyis sp. nov. is proposed. The type strain is NST-5T (=BCRC 81198T=LMG 31341T).


Assuntos
Flavobacterium/classificação , Filogenia , Tanques/microbiologia , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Peixes , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Espermidina/química , Taiwan , Vitamina K 2/análogos & derivados , Vitamina K 2/química
5.
Int J Syst Evol Microbiol ; 70(9): 5141-5148, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32812857

RESUMO

Bacterial strain CCP-6T, isolated from a freshwater pond in Taiwan, was characterized using a polyphasic taxonomy approach. Phylogenetic analyses based on 16S rRNA gene sequences and an up-to-date bacterial core gene set (92 protein clusters) indicated that strain CCP-6T is affiliated with species in the genus Rhodovarius. Strain CCP-6T was most closely related to Rhodovarius lipocyclicus CCUG 44693T with a 98.9% 16S rRNA gene sequence similarity. Cells were Gram-stain-negative, aerobic, non-motile, rod-shaped and formed light pink-coloured colonies. Optimal growth occurred at 30 °C, pH 6 and in the absence of NaCl. The major fatty acids of strain CCP-6T were C18 : 1 ω7c, C16 : 0 and C19 : 0 cyclo ω8c. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, phosphatidyldimethylethanolamine, phosphatidylmethylethanolamine, diphosphatidylglycerol, three unidentified aminophospholipids and an unidentified phospholipid. The predominant polyamine was spermidine. The major isoprenoid quinone was Q-10. The DNA G+C content of the genomic DNA was 69.3 mol%. Strain CCP-6T showed 85.8% average nucleotide identity and 14.5% digital DNA-DNA hybridization identity with Rhodovarius lipocyclicus CCUG 44693T. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain CCP-6T represents a novel species in the genus Rhodovarius, for which the name Rhodovarius crocodyli sp. nov. is proposed. The type strain is CCP-6T (=BCRC 81095T=LMG 30310T=KCTC 62188T).


Assuntos
Acetobacteraceae/classificação , Filogenia , Tanques/microbiologia , Acetobacteraceae/isolamento & purificação , Jacarés e Crocodilos , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Genes Bacterianos , Hibridização de Ácido Nucleico , Fosfolipídeos/química , Pigmentação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Espermidina/química , Taiwan , Ubiquinona/análogos & derivados , Ubiquinona/química
6.
Sci Rep ; 10(1): 11980, 2020 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-32686764

RESUMO

Bacterial diseases cause production failures in shrimp aquacultures. To understand environmental conditions and bacterial community dynamics contributing to white faeces disease (WFD) events, we analysed water quality and compared bacterial communities in water as well as in intestines and faeces of healthy and diseased shrimps, respectively, via 16S rRNA gene sequencing and qPCR of transmembrane regulatory protein (toxR), thermolabile haemolysin (tlh), and thermostable direct haemolysin genes of pathogenic Vibrio parahaemolyticus as a proxy for virulence. WFD occurred when pH decreased to 7.71-7.84, and Alteromonas, Pseudoalteromonas and Vibrio dominated the aquatic bacterial communities. The disease severity further correlated with increased proportions of Alteromonas, Photobacterium, Pseudoalteromonas and Vibrio in shrimp faeces. These opportunistic pathogenic bacteria constituted up to 60% and 80% of the sequences in samples from the early and advances stages of the disease outbreak, respectively, and exhibited a high degree of co-occurrence. Furthermore, toxR and tlh were detected in water at the disease event only. Notably, bacterial community resilience in water occurred when pH was adjusted to 8. Then WFD ceased without a mortality event. In conclusion, pH was a reliable indicator of the WFD outbreak risk. Dissolved oxygen and compositions of water and intestinal bacteria may also serve as indicators for better prevention of WFD events.


Assuntos
Aquicultura , Bactérias/crescimento & desenvolvimento , Surtos de Doenças , Fezes/microbiologia , Penaeidae/microbiologia , Animais , Bactérias/genética , Bactérias/patogenicidade , Genes Bacterianos , Filogenia , Tanques/microbiologia , Análise de Componente Principal , Virulência/genética , Microbiologia da Água
7.
BMC Public Health ; 20(1): 1128, 2020 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-32680495

RESUMO

BACKGROUND: Water is the most abundant resource on earth, however water scarcity affects more than 40% of people worldwide. Access to safe drinking water is a basic human right and is a United Nations Sustainable Development Goal (SDG) 6. Globally, waterborne diseases such as cholera are responsible for over two million deaths annually. Cholera is a major cause of ill-health in Africa and Uganda. This study aimed to determine the physicochemical characteristics of the surface and spring water in cholera endemic communities of Uganda in order to promote access to safe drinking water. METHODS: A longitudinal study was carried out between February 2015 and January 2016 in cholera prone communities of Uganda. Surface and spring water used for domestic purposes including drinking from 27 sites (lakes, rivers, irrigation canal, springs and ponds) were tested monthly to determine the vital physicochemical parameters, namely pH, temperature, dissolved oxygen, conductivity and turbidity. RESULTS: Overall, 318 water samples were tested. Twenty-six percent (36/135) of the tested samples had mean test results that were outside the World Health Organization (WHO) recommended drinking water range. All sites (100%, 27/27) had mean water turbidity values greater than the WHO drinking water recommended standards and the temperature of above 17 °C. In addition, 27% (3/11) of the lake sites and 2/5 of the ponds had pH and dissolved oxygen respectively outside the WHO recommended range of 6.5-8.5 for pH and less than 5 mg/L for dissolved oxygen. These physicochemical conditions were ideal for survival of Vibrio. cholerae. CONCLUSIONS: This study showed that surface water and springs in the study area were unsafe for drinking and had favourable physicochemical parameters for propagation of waterborne diseases including cholera. Therefore, for Uganda to attain the SDG 6 targets and to eliminate cholera by 2030, more efforts are needed to promote access to safe drinking water. Also, since this study only established the vital water physicochemical parameters, further studies are recommended to determine the other water physicochemical parameters such as the nitrates and copper. Studies are also needed to establish the causal-effect relationship between V. cholerae and the physicochemical parameters.


Assuntos
Água Potável/análise , Qualidade da Água , Abastecimento de Água/estatística & dados numéricos , Cólera/epidemiologia , Água Potável/microbiologia , Água Potável/normas , Humanos , Lagos/química , Lagos/microbiologia , Estudos Longitudinais , Nascentes Naturais/química , Nascentes Naturais/microbiologia , Tanques/química , Tanques/microbiologia , Rios/química , Rios/microbiologia , Temperatura , Uganda/epidemiologia , Vibrio cholerae , Microbiologia da Água , Abastecimento de Água/normas
8.
Int J Syst Evol Microbiol ; 70(4): 2499-2508, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32559826

RESUMO

An aerobic methane oxidizing bacterium, designated XLMV4T, was isolated from the oxic surface layer of an oil sands tailings pond in Alberta, Canada. Strain XLMV4T is capable of growth on methane and methanol as energy sources. NH4Cl and sodium nitrate are nitrogen sources. Cells are Gram-negative, beige to yellow-pigmented, motile (via a single polar flagellum), short rods 2.0-3.3 µm in length and 1.0-1.6 µm in width. A thick capsule is produced. Surface glycoprotein or cup shape proteins typical of the genera Methylococcus, Methylothermus and Methylomicrobium were not observed. Major isoprenoid quinones are Q-8 and Q-7 at an approximate molar ratio of 71 : 22. Major polar lipids are phosphoglycerol and ornithine lipids. Major fatty acids are C16 : 1 ω8+C16 : 1 ω7 (34 %), C16 : 1 ω5 (16 %), and C18 : 1 ω7 (11 %). Optimum growth is observed at pH 8.0 and 25 °C. The DNA G+C content based on a draft genome sequence is 46.7 mol%. Phylogenetic analysis of 16S rRNA genes and a larger set of conserved genes place strain XLMV4T within the class Gammaproteobacteria and family Methylococcaceae, most closely related to members of the genera Methylomicrobium and Methylobacter (95.0-97.1 % 16S rRNA gene sequence identity). In silico genomic predictions of DNA-DNA hybridization values of strain XLMV4T to the nearest phylogenetic neighbours were all below 26 %. On the basis of the data presented, strain XLMV4T is considered to represent a new genus and species for which the name Methylicorpusculum oleiharenae is proposed. Strain XLMV4T (=DSMZ DSM 27269=ATCC TSD-186) is the type strain.


Assuntos
Methylococcaceae/classificação , Campos de Petróleo e Gás/microbiologia , Filogenia , Tanques/microbiologia , Alberta , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Metano/metabolismo , Metanol/metabolismo , Methylococcaceae/isolamento & purificação , Hibridização de Ácido Nucleico , Pigmentação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/química
9.
J Chem Ecol ; 46(5-6): 534-543, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32468489

RESUMO

Many organisms synthesize secondary metabolites against natural enemies. However, to which environmental factors the production of these metabolites is adjusted to is poorly investigated in animals, especially so in vertebrates. Bufadienolides are steroidal compounds that are present in a wide range of plants and animals and, if present in large quantities, can provide protection against natural enemies, such as pathogens. In a correlative study involving 16 natural populations we investigated how variation in bufadienolide content of larval common toads (Bufo bufo) is associated with the bacterial community structure of their aquatic environment. We also evaluated pond size, macrovegetation cover, and the abundance of predators, conspecifics and other larval amphibians. We measured toxin content of tadpoles using HPLC-MS and determined the number of bufadienolide compounds (NBC) and the total quantity of bufadienolides (TBQ). AICc-based model selection revealed strong relationships of NBC and TBQ with bacterial community structure of the aquatic habitat as well as with the presence of conspecific tadpoles. The observed relationships may have arisen due to adaptation to local bacterial communities, phenotypic plasticity, differential biotransformation of toxin compounds by different bacterial communities, or a combination of these processes. Bacterial groups that contribute to among-population variation in toxin content remain to be pinpointed, but our study suggesting that toxin production may be influenced by the bacterial community of the environment represents an important step towards understanding the ecological and evolutionary processes leading to microbiota-mediated variation in skin toxin profiles of aquatic vertebrates.


Assuntos
Bactérias , Bufanolídeos/química , Bufo bufo , Larva/química , Microbiota , Tanques/microbiologia , Animais , Bufo bufo/crescimento & desenvolvimento , Hungria
10.
Ecotoxicol Environ Saf ; 199: 110738, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32447139

RESUMO

The increasing prevalence of antibiotic resistance genes (ARGs) is a challenge to the health of humans, animals and the environments. Human activities and aquatic environments can increase ARGs. Few studies have focused on the temporal variation of aquatic bacteria with multiple ARGs in aquatic environments affected by human production activity. We studied culturable bacteria (CB) carrying ARGs, including sul1, sul2, floR, strA and gyrA in the shrimp hepatopancreas (HP) and in pond water during shrimp culture. The relative abundance of ARGs carried by CB in HP was higher than that in water (P < 0.05). However, CB carrying ARGs generally varied in random pattern. The correlation of sul2 abundance was significantly positive in HP, while that of strA abundance was significantly negative in water (P < 0.05) during shrimp culture. Among all of the CB, 33.59% carried multiple ARGs. Temporal distance-decay analysis indicated that CB carrying ARGs in water were more resistant to the effects of human activity. CB carrying ARGs varied temporally in HP and pond water during shrimp culture. These results demonstrate that multiple ARGs are carried by CB, and these varied with the phase of aquatic culture.


Assuntos
Crustáceos/microbiologia , Resistência Microbiana a Medicamentos/genética , Monitoramento Ambiental/métodos , Genes Bacterianos , Hepatopâncreas/microbiologia , Tanques/microbiologia , Animais , Aquicultura , Bactérias/genética , Bactérias/isolamento & purificação , China , Crustáceos/crescimento & desenvolvimento , Humanos , Alimentos Marinhos , Microbiologia da Água
11.
J Water Health ; 18(2): 127-144, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32300087

RESUMO

Microfungi occurring in surface water may represent an important health risk. Recreational water reservoirs are a potential reservoir of pathogenic fungi. The aim of the study was to assess the diversity of mycobiota in selected artificial bathing reservoirs with regard to its biosafety for the human population. The studies were conducted during the summer of 2016 in three research seasons (June (I), July and August (II), and September (III)), taking into account the various periods of recreational activities. Filamentous fungi were isolated from water samples collected at five different ponds utilized for recreation. From 162 water samples, 149 fungal taxa of filamentous fungi were identified: 140 were classified to species level and only nine to genus level. Aspergillus fumigatus was the dominant species. The highest species richness (S) was noted in June, with 93 fungal taxa (Menhinick's index from 2.65 to 4.49). Additionally, in season I, the highest diversity of fungal species was revealed (Simpson's diversity index from 0.83 to 0.99). The average number of CFU/1 mL sample ranged between 0.4 and 4.6 depending on the time of sampling and ponds. Of all the isolated species, 128 were clinically relevant (11 from RG-2 and 117 from RG-1), highlighting the need to introduce seasonal mycological monitoring of such reservoirs.


Assuntos
Fungos/isolamento & purificação , Tanques/microbiologia , Saúde Pública , Microbiologia da Água , Monitoramento Ambiental , Humanos , Estações do Ano
12.
J Vet Diagn Invest ; 32(3): 369-381, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32306863

RESUMO

Microcystis is a widespread freshwater cyanobacterium that can produce microcystin, a potent hepatotoxin harmful to animals and humans. Therefore, it is crucial to monitor for the presence of toxigenic Microcystis spp. to provide early warning of potential microcystin contamination. Microscopy, which has been used traditionally to identify Microcystis spp., cannot differentiate toxigenic from non-toxigenic Microcystis. We developed a PCR-based method to detect toxigenic Microcystis spp. based on detection of the microcystin synthetase C (mcyC) gene and 16S rRNA gene. Specificity was validated against toxic and nontoxic M. aeruginosa strains, as well as 4 intergeneric freshwater cyanobacterial strains. Analytical sensitivity was as low as 747 fg/µL genomic DNA (or 3 cells/µL) for toxic M. aeruginosa. Furthermore, we tested 60 water samples from 4 farm ponds providing drinking water to swine facilities in the midwestern United States using this method. Although all water samples were positive for Microcystis spp. (i.e., 16S rRNA gene), toxigenic Microcystis spp. were detected in only 34 samples (57%). Seventeen water samples contained microcystin (0.1-9.1 µg/L) determined with liquid chromatography-mass spectrometry, of which 14 samples (82%) were positive for mcyC. A significant correlation was found between the presence of toxigenic Microcystis spp. and microcystin in water samples (p = 0.0004). Our PCR method can be a low-cost molecular tool for rapid and specific identification of toxigenic Microcystis spp. in farm ponds, improving detection of microcystin contamination, and ensuring water safety for farm animals.


Assuntos
Microcistinas/isolamento & purificação , Microcystis/isolamento & purificação , Reação em Cadeia da Polimerase/veterinária , Tanques/microbiologia , Proteínas de Bactérias/análise , Toxinas Bacterianas/análise , Eutrofização , Fazendas , Meio-Oeste dos Estados Unidos , Reação em Cadeia da Polimerase/métodos , RNA Bacteriano/análise , RNA Ribossômico 16S/análise
13.
Arch Microbiol ; 202(7): 1757-1762, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32342124

RESUMO

An aerobic, oligotrophic, Gram-positive, non-sporulating, motile, rod-shaped, palladium-leaching bacterial strain, Deinococcus sp. KR-1, was previously isolated from pond water collected in Japan. This strain grew at 10 °C to 40 °C (optimum 30 °C), at pH 4.5 to 11.5 (optimum pH 8.0), and in the presence of 2.0% NaCl. Its major cellular fatty acids were C15: 1ω6 and C16 : 1ω7c. The quinone system was menaquinone 8. Multilocus sequence analysis based on partial sequences of four housekeeping genes (atpD, dnaA, gyrB and rpoB) showed that branching of Deinococcus sp. KR-1 was distant to those of Deinococcus type strains. The genome average nucleotide identity value between strain KR-1 and its closest related Deinococcus type strain was less than 95.69%. Based on its phenotypic, chemotaxonomic and phylogenetic data, strain KR-1 (= HUT-8138T = KCTC 33977T) can be considered a novel species within the genus Deinococcus with the proposed name Deinococcus kurensis sp. nov.


Assuntos
Deinococcus/classificação , Filogenia , Tanques/microbiologia , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Deinococcus/genética , Ácidos Graxos/análise , Japão , Tipagem de Sequências Multilocus , Análise de Sequência de DNA , Especificidade da Espécie , Vitamina K 2/análogos & derivados
14.
Int J Syst Evol Microbiol ; 70(4): 2888-2895, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32213255

RESUMO

A novel bacterial strain, designated KMB7T, isolated from a freshwater pond in Taiwan, was characterized using a polyphasic taxonomic approach. Cells were Gram-stain-negative, motile by means of a single polar flagellum, rod-shaped and formed cream colonies. Optimal growth occurred at 25 °C, pH 7, and in the absence of NaCl. Phylogenetic analyses based on 16S rRNA gene sequences and an up-to-date bacterial core gene set (92 protein clusters) indicated that strain KMB7T is affiliated with species in the genus Aquabacterium. The 16S rRNA gene sequence similarity indicated that strain KMB7T is closely related to species within the genus Aquabacterium (95.2-97.6 % sequence similarity) and is most similar to A. fontiphilum CS-6T (97.6 %), followed by A. parvum B6T (97.5 %). The average nucleotide identity and digital DNA-DNA hybridization identity between strain KMB7T and the closely related strains were 74.6-78.0 % and 19.0-21.2 %, respectively. The major fatty acids of strain KMB7T were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C18 : 1 ω7c and C16 : 0. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylserine, diphosphatidylglycerol and four unidentified phospholipids. The sole isoprenoid quinone was ubiquinone-8 (Q-8). Genomic DNA G+C content of strain KMB7T was 65.4 %. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain KMB7T should be classified in a novel species of the genus Aquabacterium, for which the name Aquabacterium lacunae sp. nov. is proposed. The type strain is KMB7T (=BCRC 81156T=LMG 30924T=KCTC 62867T).


Assuntos
Burkholderiales/classificação , Filogenia , Tanques/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , Burkholderiales/isolamento & purificação , DNA Bacteriano/genética , Ácidos Graxos/química , Genes Bacterianos , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Taiwan , Ubiquinona/química
15.
Curr Microbiol ; 77(6): 1125-1134, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32002626

RESUMO

Two moderately halophilic strains SBS 10T and SSO 06 were isolated from the saltern crystallizer ponds of the hypersaline Sambhar Salt Lake in India. Strains were aerobic, Gram-stain-negative, and rod shaped. Phylogenetic analysis based on the 16S rRNA gene sequences indicated that two strains belong to the genus Halomonas in the Gammaproteobacteria, with highest 16S rRNA gene sequence similarities with Halomonas gudaonensis LMG 23610T (98.2% similarity) and Halomonas campaniensis 5AGT (99.0% similarity). Strains grew optimally at 37 °C, pH 7.5-8.0 in the presence of 5-8% (w/v) NaCl. The major fatty acids of the strain SBS 10T were C18:1ω7c (54.37%), C16:0 (25.69%), C16:1 × 7c/C16:1 × 6c (13.28%), and C12:0 (1.21%). The G+C content was 63.6 mol % (Tm). Phenotypic features, fatty acids profile, and DNA G+C content supported placement of the strain SBS 10T in the genus Halomonas having distinct characteristics with related strains. Analysis of the housekeeping genes: gryB and rpoD and in silico DNA-DNA hybridization between the strain SBS 10T and its type strain Halomonas gudaonensis (LMG 23610T) further revealed the strain SBS 10T to be a distinct species. On the basis of the phenotypic, chemotaxonomic and phylogenetic analysis, the strain SBS 10T is considered to represent a novel species for which the name Halomonas sambharensis is proposed. The type strain is SBS 10T (= MTCC 12313T = LMG 30344T).


Assuntos
Halomonas/classificação , Halomonas/fisiologia , Tanques/microbiologia , Sais/metabolismo , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos , Genes Essenciais/genética , Halomonas/química , Halomonas/citologia , Concentração de Íons de Hidrogênio , Índia , Lagos , Hibridização de Ácido Nucleico , Fenótipo , Filogenia , Tanques/química , RNA Ribossômico 16S/genética , Sais/análise , Análise de Sequência de DNA , Especificidade da Espécie , Temperatura
16.
J Bacteriol ; 202(8)2020 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-32015145

RESUMO

Bdellovibrio and like organisms are abundant environmental parasitoids of prokaryotes that show diverse predation strategies. The vast majority of studied Bdellovibrio bacteria and like organisms deploy intraperiplasmic replication inside the prey cell, while few isolates with smaller genomes consume their prey from the outside in an epibiotic manner. The novel parasitoid "Candidatus Bdellovibrio qaytius" was isolated from a eutrophic freshwater pond in British Columbia, where it was a continual part of the microbial community. "Ca Bdellovibrio qaytius" was found to preferentially prey on the betaproteobacterium Paraburkholderia fungorum without entering the periplasm. Despite its epibiotic replication strategy, "Ca Bdellovibrio" encodes a large genomic complement more similar to that of complex periplasmic predators. Functional genomic annotation further revealed several biosynthesis pathways not previously found in epibiotic predators, indicating that "Ca Bdellovibrio" represents an intermediate phenotype and at the same time narrowing down the genomic complement specific to epibiotic predators. In phylogenetic analysis, "Ca Bdellovibrio qaytius" occupies a widely distributed, but poorly characterized, basal cluster within the genus Bdellovibrio This suggests that epibiotic predation might be a common predation type in nature and that epibiotic predation could be the ancestral predation type in the genus.IMPORTANCE Bdellovibrio and like organisms are bacteria that prey on other bacteria and are widespread in the environment. Most of the known Bdellovibrio species enter the space between the inner and outer prey membrane, where they consume their prey cells. However, one Bdellovibrio species has been described that consumes its prey from the outside. Here, we describe "Ca Bdellovibrio qaytius," a novel member of the genus Bdellovibrio that also remains outside the prey cell throughout its replication cycle. Unexpectedly, the genome of "Ca Bdellovibrio" is much more similar to the genomes of intracellular predators than to the species with a similar life cycle. Since "Ca Bdellovibrio" is also a basal representative of this genus, we hypothesize that extracellular predation could be the ancestral predation strategy.


Assuntos
Bdellovibrio/genética , Bdellovibrio/classificação , Bdellovibrio/isolamento & purificação , Bdellovibrio/fisiologia , Burkholderiaceae/fisiologia , Genoma Bacteriano , Genômica , Filogenia , Tanques/microbiologia
17.
Microbes Environ ; 35(1)2020.
Artigo em Inglês | MEDLINE | ID: mdl-32037377

RESUMO

Although the bioavailability of rare earth elements (REEs, including scandium, yttrium, and 15 lanthanides) has not yet been examined in detail, methane-oxidizing bacteria (methanotrophs) were recently shown to harbor specific types of methanol dehydrogenases (XoxF-MDHs) that contain lanthanides in their active site, whereas their well-characterized counterparts (MxaF-MDHs) were Ca2+-dependent. However, lanthanide dependency in methanotrophs has not been demonstrated, except in acidic environments in which the solubility of lanthanides is high. We herein report the isolation of a lanthanide-dependent methanotroph from a circumneutral environment in which lanthanides only slightly dissolved. Methanotrophs were enriched and isolated from pond sediment using mineral medium supplemented with CaCl2 or REE chlorides. A methanotroph isolated from the cerium (Ce) chloride-supplemented culture, Methylosinus sp. strain Ce-a6, was clearly dependent on lanthanide. Strain Ce-a6 only required approximately 30 nM lanthanide chloride for its optimal growth and exhibited the ability to utilize insoluble lanthanide oxides, which may enable survival in circumneutral environments. Genome and gene expression analyses revealed that strain Ce-a6 lost the ability to produce functional MxaF-MDH, and this may have been due to a large-scale deletion around the mxa gene cluster. The present results provide evidence for lanthanide dependency as a novel survival strategy by methanotrophs in circumneutral environments.


Assuntos
Genoma Bacteriano/genética , Elementos da Série dos Lantanídeos/metabolismo , Proteobactérias/genética , Proteobactérias/isolamento & purificação , Oxirredutases do Álcool/genética , Proteínas de Bactérias/genética , Meios de Cultura/metabolismo , Sedimentos Geológicos/microbiologia , Metais Terras Raras/metabolismo , Metano/metabolismo , Methylosinus/classificação , Methylosinus/genética , Methylosinus/isolamento & purificação , Methylosinus/metabolismo , Tanques/microbiologia , Proteobactérias/classificação , Proteobactérias/fisiologia , RNA Ribossômico 16S/genética
18.
J Appl Microbiol ; 129(2): 243-255, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32043695

RESUMO

AIMS: The present study aimed to reveal microbial relationship between shrimp intestine and ambient in higher place shrimp ponds from the aspects of composition and function. METHODS AND RESULTS: Metagenome and 16S rRNA gene sequencing were used to compare microbial compositions and functions of water, effluent and shrimp intestine in higher place Litopenaeus vannamei ponds. Although the three groups had similar dominant phyla, such as Proteobacteria, Bacteroidetes and Tenericutes, their bacterial compositions at the genus level were obviously different. Compared to effluent and intestine, the relative abundance of Vibrio as common opportunistic pathogen for shrimp was significantly higher in water. However, cluster analysis showed that intestinal microbial composition was more similar to that of effluent than water. Metagenomic data showed that the predominant microbial functions in the three groups were mostly related to energy production and biosynthesis, while carbohydrate metabolism was relatively enriched in intestinal microbiota. More importantly, Proteobacteria played a critical role in carbon metabolism and biosynthesis of amino acids in the three habitats, and Vibrio had the most functions related to bacterial virulence and infection. CONCLUSIONS: Shrimp intestinal microbiota had a close correlation with the ambient microbiota in both structure and function. As the most dominant phylum, Proteobacteria was very important for microbiota communication and nutrient cycling in higher place shrimp ponds. Moreover, due to the pathogenicity, it was necessary to monitor the abundant changes of Vibrio in water to decrease the risk of shrimp disease outbreaks. SIGNIFICANCE AND IMPACT OF THE STUDY: These above results may be helpful to comprehensively understand the characteristics and functions of microbiota in higher place shrimp ponds, thereby providing basic information for developing the management strategies of entire microbiota to sustain shrimp health.


Assuntos
Intestinos/microbiologia , Microbiota/fisiologia , Penaeidae/microbiologia , Tanques/microbiologia , Frutos do Mar/microbiologia , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Metagenoma , Microbiota/genética , RNA Ribossômico 16S/genética , Águas Residuárias/microbiologia
19.
Appl Microbiol Biotechnol ; 104(5): 2229-2241, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31915903

RESUMO

The aquatic microbial community is sensitive to environmental change; however, the impacts of those changes combined with disease outbreaks affecting S. paramamosain are unknown. Thus, from March to October, we explored the interaction between aquacultural environmental conditions and microbial composition and function in open-air aquaculture ponds containing S. paramamosain in Southern China. The microbial community structure was significantly positively correlated with microbial community function. The environment variables such as temperature and salinity during May and June changed more quickly compared with other periods, resulting changes in the structure and function of the microbial community affected S. paramamosain survivability, with higher crab mortality observed from May to June compared with other periods. These included changes in the relative abundance of Microtrichales, Synechococcales, Rhodobacterales, Chitinophagales, and SAR11_clade, and corresponding functions associated with glycolysis and/or gluconeogenesis, porphyrin and chlorophyll metabolism, photosynthetic proteins, and transcription factors. These changes could impact S. paramamosain mortality and be used to evaluate the health status of the ponds. Though the environment variables during July~October changed slowly comparing to May and June, the ponds microflora changed which benefit S. paramamosain survivability with correspondingly low S. paramamosain mortality. Therefore, rapid environmental change alters the structure and function of the aquatic microflora, increasing S. paramamosain mortality.


Assuntos
Braquiúros/fisiologia , Microbiota , Tanques/microbiologia , Microbiologia da Água , Animais , Aquicultura , China , Monitoramento Ambiental , Microbiota/genética , Nutrientes/análise , Tanques/química , Salinidade , Estações do Ano , Temperatura
20.
Vet Res Commun ; 44(1): 9-18, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31965460

RESUMO

Abundance and antibiotic resistance of bacteria of the genus Aeromonas isolated from the water of three carp ponds were studied. The number of those bacteria differed between the studied ponds, sites and season. The results of the present study showed that planktonic Aeromonas inhabiting those ponds strongly differed in the resistance level to tested antibiotics. These microorganisms were the most resistant to amoxicillin, ampicillin, clindamycin and penicillin. However, all isolates Aeromonas were susceptible to gentamycin and streptomycin. Majority of bacterial strains were characterized by resistance to 4-6 of the 12 antibiotics tested. Bacterial resistance to antibiotics depended on their chemical structure. Aeromonas strains isolated from the studied ponds were the most resistant to ß-lactam and lincosamides antibiotics, while the most susceptible to aminoglycosides, chloramphenicols and fluoroquinolones.


Assuntos
Aeromonas/efeitos dos fármacos , Antibacterianos/química , Farmacorresistência Bacteriana , Tanques/microbiologia , Aeromonas/fisiologia , Animais , Aquicultura , Carpas , Polônia , Densidade Demográfica
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