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1.
Arch Virol ; 168(2): 71, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36658443

RESUMO

Despite the ecological significance of viral communities, phages remain insufficiently studied. Current genomic databases lack high-quality phage genome sequences linked to specific bacteria. Bacteria of the genus Erwinia are known to colonize the phyllosphere of plants, both as commensals and as pathogens. We isolated three Erwinia billingiae phages-Zoomie, Pecta, and Snitter-from organic household waste. Based on sequence similarity to their closest relatives, we propose that they represent three new genera: "Pectavirus" within the family Zobellviridae, "Snittervirus" in the subfamily Tempevirinae, family Drexlerviridae, and "Zoomievirus" within the family Autographiviridae, which, together with the genus Limelightvirus, may constitute a new subfamily.


Assuntos
Bacteriófagos , Erwinia , Bacteriófagos/genética , Genoma Viral , Erwinia/genética
2.
Arch Virol ; 168(3): 89, 2023 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-36786922

RESUMO

Despite Curtobacterium spp. often being associated with the plant phyllosphere, i.e., the areal region of different plant species, only one phage targeting a member of the genus Curtobacterium has been isolated so far. In this study, we isolated four novel plaque-forming Curtobacterium phages, Reje, Penoan, Parvaparticeps, and Pize, with two novel Curtobacterium strains as propagation hosts. Based on the low nucleotide intergenomic similarity (<32.4%) between these four phages and any phage with a genome sequence in the NCBI database, we propose the establishment of the four genera, "Rejevirus", "Pizevirus", "Penoanvirus", and "Parvaparticepsvirus", all in the class of Caudoviricetes.


Assuntos
Actinomycetales , Bacteriófagos , Bacteriófagos/genética , Actinomycetales/genética , Genoma Viral
3.
Artigo em Inglês | MEDLINE | ID: mdl-35380531

RESUMO

Here we present the description of a novel Pseudomonas species, designated Pseudomonas rustica sp. nov., which was isolated from raw milk samples obtained from Germany. Results of initial 16S rRNA gene sequence analysis assigned the strain into the genus Pseudomonas and showed Pseudomonas helmanticensis, Pseudomonas neuropathica and Pseudomonas atagonensis to be its closest relatives. Further studies including sequence analysis of the rpoB gene, multi-gene phylogenetic tree reconstruction, whole-genome sequence comparisons, cellular fatty acid analysis and chemotaxonomic characterization showed a clear separation from the known Pseudomonas species. Isolate MBT-4T was closely related to Pseudomonas helmanticensis, 'Pseudomonas crudilactis' and Pseudomonas neuropathica with average nucleotide identities based on blast values of 88.8, 88.8 and 88.6%, respectively. Therefore, the strain can be classified into the Pseudomonas koreensis subgroup of the Pseudomonas fluorescens group. The G+C content of strain MBT-4T was 58.9 mol%. The strain was catalase- and oxidase-positive, while the ß-galactosidase reaction was negative. Growth occurred between 4 and 30 °C and at pH values from pH 6.0 to 8.0. In conclusion, strain MBT-4T belongs to a novel species, for which the name Pseudomonas rustica sp. nov. is proposed. The type strain is MBT-4T (=DSM 112348T=LMG 32241T) and strain MBT-17 is also a representative of this species.


Assuntos
Ácidos Graxos , Leite , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Fazendas , Ácidos Graxos/química , Genes Bacterianos , Hibridização de Ácido Nucleico , Filogenia , Pseudomonas , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
4.
Arch Virol ; 167(10): 2049-2056, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35764845

RESUMO

Some serovars of Salmonella can cause life-threatening diarrhoeal diseases and bacteriemia. The emergence of multidrug-resistant strains has led to a need for alternative treatments such as phage therapy, which requires available, well-described, diverse, and suitable phages. Phage akira was found to lyse 19 out of 32 Salmonella enterica serovars and farm isolates tested, although plaque formation was observed with only two S. Enteritidis and one S. Typhimurium strain. Phage akira encodes anti-defence genes against type 1 R-M systems, is distinct (<65% nucleotide sequence identity) from related phages and has siphovirus morphology. We propose that akira represents a new genus in the class Caudoviricetes.


Assuntos
Bacteriófagos , Fagos de Salmonella , Salmonella enterica , Siphoviridae , Bacteriófagos/genética , Fagos de Salmonella/genética , Salmonella enteritidis/genética , Salmonella typhimurium/genética
5.
Arch Virol ; 166(10): 2887-2894, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34347170

RESUMO

The complete genome sequence of the virulent bacteriophage PMBT3, isolated on the proteolytic Pseudomonas grimontii strain MBTL2-21, showed no significant similarity to other known phage genome sequences, making this phage the first reported to infect a strain of P. grimontii. Electron microscopy revealed PMBT3 to be a member of the family Siphoviridae, with notably long and flexible whiskers. The linear, double-stranded genome of 87,196 bp has a mol% G+C content of 60.4 and contains 116 predicted protein-encoding genes. A putative tellurite resistance (terB) gene, originally reported to occur in the genome of a bacterium, was detected in the genome of phage PMBT3.


Assuntos
Pseudomonas/virologia , Animais , Bacteriólise , Composição de Bases , Sequência de Bases , DNA Viral/genética , Genoma Viral/genética , Especificidade de Hospedeiro , Leite/microbiologia , Filogenia , Fagos de Pseudomonas/classificação , Fagos de Pseudomonas/genética , Fagos de Pseudomonas/fisiologia , Fagos de Pseudomonas/ultraestrutura , Siphoviridae/classificação , Siphoviridae/genética , Siphoviridae/fisiologia , Siphoviridae/ultraestrutura , Proteínas Virais/genética , Vírion/ultraestrutura
6.
PLoS One ; 19(6): e0305563, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38917141

RESUMO

Efficient city logistics is essential to build smart sustainable cities where inhabitants' well-being is a priority. Meanwhile, despite the great importance of city logistics processes, their improvement is problematic for many cities. Although solutions from the field of emerging technologies are more and more often used, the question is whether implementing technological tools and filling cities with sensors is a sufficient solution that can solve the problems of intensely growing urban freight transport. The aim of the paper is to examine the role of knowledge management in city logistics and identify barriers to the implementation of knowledge-based city logistics. A key element of the research procedure was an expert survey, to which 31 international experts specialising in city logistics issues were invited, characterised by extensive experience working on research projects in the area of interest. Four knowledge management processes have been transferred to the city logistics area. The results of the study show that the difficulties are observed mainly in the processes of data gathering and knowledge acquisition. The main reason for difficulties in that area is the reluctance of city users, retailers, transport and logistics operators to share information. Identifying these processes as the most problematic is a valuable hint for logistics managers, municipalities and academics. To improve knowledge-based city logistics, it is therefore necessary to focus on these processes and look for the best solutions and new forms of organisational and business support. The solution to the problems identified in the study is the proposal to create a city logistics collaborative knowledge base which is a combination of an IT tool - the CL knowledge management platform, and the Freight Quality Partnership.


Assuntos
Cidades , Humanos , Meios de Transporte , Gestão do Conhecimento , Inquéritos e Questionários , Conhecimento , Planejamento de Cidades/métodos
7.
Front Microbiol ; 12: 653501, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34305825

RESUMO

Exudative epidermitis (EE), also known as greasy pig disease, is one of the most frequent skin diseases affecting piglets. Zoonotic infections in human occur. EE is primarily caused by virulent strains of Staphylococcus (S.) hyicus. Generally, antibiotic treatment of this pathogen is prone to decreasing success, due to the incremental development of multiple resistances of bacteria against antibiotics. Once approved, bacteriophages might offer interesting alternatives for environmental sanitation or individualized treatment, subject to the absence of virulence and antimicrobial resistance genes. However, genetic characterization of bacteriophages for S. hyicus has, so far, been missing. Therefore, we investigated a piglet raising farm with a stock problem due to EE. We isolated eleven phages from the environment and wash water of piglets diagnosed with the causative agent of EE, i.e., S. hyicus. The phages were morphologically characterized by electron microscopy, where they appeared Siphoviridae-like. The genomes of two phages were sequenced on a MiSeq instrument (Illumina), resulting in the identification of a new virulent phage, PITT-1 (PMBT8), and a temperate phage, PITT-5 (PMBT9). Sequencing of three host bacteria (S. hyicus) from one single farm revealed the presence of two different strains with genes coding for two different exfoliative toxin genes, i.e., exhA (2 strains) and exhC (1 strain). The exhC-positive S. hyicus strain was only weakly lysed by most lytic phages. The occurrence of different virulent S. hyicus strains in the same outbreak limits the prospects for successful phage treatment and argues for the simultaneous use of multiple and different phages attacking the same host.

8.
Front Microbiol ; 11: 602444, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33391221

RESUMO

Use of bacteriophages, which are viruses that kill bacteria, for biocontrol of pathogens and antimicrobial resistant bacteria has become increasingly important in recent years. As traditional culture-based methods are laborious and time-consuming, practicable use of bacteriophages will hinge on development of rapid and high throughput methods to analyze, characterize and screen large bacteriophage libraries. We thus established a novel method to fluorescently tag bacteriophages for virus screening and interaction studies, without the need for complicated and laborious purification procedures or genetic engineering of viruses to express fluorescent proteins. Bacteriophage PMBT14 was tagged using DNA dye Syto 13. Simply by using a membrane filter, tagged bacteriophages can be separated from non-sequestered excess dye rapidly, effortlessly, and cheaply. The procedure takes less than 30 min and makes use of simple laboratory consumables that are already commonly used for bacteriophage preparations. As proof of concept, we present here flow cytometric methods to analyze bacteriophage binding, infection and killing that are very accessible for high throughput analysis. We show that the resulting fluorescently tagged bacteriophage can be used to specifically stain its host bacterium Pseudomonas fluorescens DSM 50090. Individual fluorescent bacteriophages, their binding to and initial infection of bacteria could also be observed using confocal microscopy. The infection process was halted by the metabolic inhibitor sodium azide, suggesting a requirement of host metabolic processes for penetration by PMBT14. Flow cytometric live/dead assays was used as a complementary method to determine bacteriophage infection of its host. We made preliminary efforts to adapt the tagging method to two other bacteriophages and discuss potential pitfalls and solutions in the use of tagged phages. Fluorescent phage tagging has previously been demonstrated to facilitate analysis of bacteriophage-host interactions. The method adopted in this study makes it fast, easy as well as cost effective.

9.
Int J Food Microbiol ; 241: 308-317, 2017 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-27835774

RESUMO

Thirteen whey powders and 5 whey powder formulations were screened for the presence of dairy bacteriophages using a representative set of 8 acid-producing Lactococcus lactis and 5 Streptococcus thermophilus, and 8 flavour-producing Leuconostoc pseudomesenteroides and Leuconostoc mesenteroides strains. Lytic L. lactis phages were detected in all samples, while S. thermophilus and Leuconostoc phages were present in 50% or 40% of the samples, respectively. Maximal phage titers were 6×107 plaque-forming units (pfu)/g of whey powder for L. lactis phages, 1×107pfu/g for Leuconostoc phages and 1×105pfu/g for S. thermophilus phages. In total, 55 phages were isolated and characterized. Thirty one of the 33 lactococcal phages tested belonged to the wide-spread 936 phage group. In the course of this study, a PCR detection method for Leuconostoc phages (Ali et al., 2013) was adapted to new phage isolates. Furthermore, a remarkably high stability of phages in whey powder samples was documented during a long-term storage period of 4 years.


Assuntos
Bacteriófagos/crescimento & desenvolvimento , Preservação Biológica/métodos , Soro do Leite/microbiologia , Bacteriófagos/metabolismo , Meios de Cultura/metabolismo , Pós , Preservação Biológica/instrumentação
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