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1.
Viruses ; 13(11)2021 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-34834977

RESUMO

Yersinia enterocolitica is a food-borne Gram-negative pathogen responsible for several gastrointestinal disorders. Host-specific lytic bacteriophages have been increasingly used recently as an alternative or complementary treatment to combat bacterial infections, especially when antibiotics fail. Here, we describe the proteogenomic characterization and host receptor identification of the siphovirus vB_YenS_ϕR2-01 (in short, ϕR2-01) that infects strains of several Yersinia enterocolitica serotypes. The ϕR2-01 genome contains 154 predicted genes, 117 of which encode products that are homologous to those of Escherichia bacteriophage T5. The ϕR2-01 and T5 genomes are largely syntenic, with the major differences residing in areas encoding hypothetical ϕR2-01 proteins. Label-free mass-spectrometry-based proteomics confirmed the expression of 90 of the ϕR2-01 genes, with 88 of these being either phage particle structural or phage-particle-associated proteins. In vitro transposon-based host mutagenesis and ϕR2-01 adsorption experiments identified the outer membrane vitamin B12 receptor BtuB as the host receptor. This study provides a proteogenomic characterization of a T5-type bacteriophage and identifies specific Y. enterocolitica strains sensitive to infection with possible future applications of ϕR2-01 as a food biocontrol or phage therapy agent.


Assuntos
Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Siphoviridae/fisiologia , Yersinia/virologia , Bacteriófagos/classificação , Bacteriófagos/genética , Bacteriófagos/isolamento & purificação , Bacteriófagos/fisiologia , Genoma Viral , Proteômica , Siphoviridae/classificação , Siphoviridae/genética , Siphoviridae/isolamento & purificação , Yersinia/genética , Yersinia enterocolitica/virologia
2.
Int J Mol Sci ; 21(12)2020 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-32575645

RESUMO

Increasing multidrug resistance has led to renewed interest in phage-based therapy. A combination of the bacteriophages and antibiotics presents a promising approach enhancing the phage therapy effectiveness. First, phage candidates for therapy should be deeply characterized. Here we characterize the bacteriophage vB_AbaP_AGC01 that poses antibacterial activity against clinical Acinetobacter baumannii strains. Moreover, besides genomic and phenotypic analysis our study aims to analyze phage-antibiotic combination effectiveness with the use of ex vivo and in vivo models. The phage AGC01 efficiently adsorbs to A. baumannii cells and possesses a bacteriolytic lifecycle resulting in high production of progeny phages (317 ± 20 PFU × cell-1). The broad host range (50.27%, 93 out of 185 strains) against A. baumannii isolates and the inability of AGC01 to infect other bacterial species show its high specificity. Genomic analysis revealed a high similarity of the AGC01 genome sequence with that of the Friunavirus genus from a subfamily of Autographivirinae. The AGC01 is able to significantly reduce the A. baumannii cell count in a human heat-inactivated plasma blood model (HIP-B), both alone and in combination with antibiotics (gentamicin (GEN), ciprofloxacin (CIP), and meropenem (MER)). The synergistic action was observed when a combination of phage treatment with CIP or MER was used. The antimicrobial activity of AGC01 and phage-antibiotic combinations was confirmed using an in vivo larva model. This study shows the greatest increase in survival of G. mellonella larvae when the combination of phage (MOI = 1) and MER was used, which increased larval survival from 35% to 77%. Hence, AGC01 represents a novel candidate for phage therapy. Additionally, our study suggests that phages and antibiotics can act synergistically for greater antimicrobial effect when used as combination therapy.


Assuntos
Infecções por Acinetobacter/terapia , Acinetobacter baumannii/virologia , Antibacterianos/uso terapêutico , Bacteriófagos/fisiologia , Lepidópteros/microbiologia , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/crescimento & desenvolvimento , Animais , Antibacterianos/farmacologia , Bacteriólise , Bacteriófagos/classificação , Bacteriófagos/genética , Ciprofloxacina/farmacologia , Ciprofloxacina/uso terapêutico , Terapia Combinada , Modelos Animais de Doenças , Genoma Viral , Temperatura Alta , Humanos , Meropeném/farmacologia , Meropeném/uso terapêutico , Terapia por Fagos , Fenótipo , Especificidade da Espécie , Sequenciamento Completo do Genoma
3.
FEMS Microbiol Lett ; 366(9)2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31095303

RESUMO

Pectobacterium atrosepticum is a species of plant pathogenic bacteria responsible for significant losses in potato production worldwide. Pectobacterium atrosepticum can cause blackleg disease on potato stems as well as the tuber disease termed potato soft rot. Methods for the effective control of these diseases are limited and are primarily based on good agricultural practices. Bacteriophages, viruses of bacteria, could be used as an alternative, environmentally friendly, control measure. Here, we describe the isolation and characterization of 29 phages virulent to P. atrosepticum. The phages belong to 12 different species based on a 95% sequence identity cut-off. Furthermore, based on sequence diversity and propagation results, we selected six of these phages to form a phage cocktail. The phages in the cocktail was tested on a number of P. atrosepticum strains in order to determine their host range. The phages was found to lyse 93% of the tested strains. The cocktail was subsequently tested for its effectiveness in combatting potato soft rot under simulated storage conditions. Use of the phage cocktail reduced both disease incidence and disease severity by 61% and 64%, respectively, strongly indicating that phage biocontrol has the potential to reduce the economic impact of soft rot in potato production.


Assuntos
Bacteriófagos/isolamento & purificação , Armazenamento de Alimentos/métodos , Pectobacterium/patogenicidade , Doenças das Plantas/prevenção & controle , Tubérculos/microbiologia , Solanum tuberosum/microbiologia , Bacteriófagos/classificação , Agentes de Controle Biológico , Pectobacterium/virologia , Filogenia , Doenças das Plantas/microbiologia
4.
J Antimicrob Chemother ; 74(4): 854-864, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30649322

RESUMO

OBJECTIVES: Antimicrobial resistance genes (ARGs) can be transferred by means of mobile genetic elements, which play a critical role in the dissemination of resistance in the bacterial community. ARG transmission within mobile genetic elements has been reported in plasmids and transposons but less frequently in bacteriophages. Here, the bacteriophage fraction of seven human faecal samples was purified and deep-sequenced to detect the presence of ARGs in the phage particles. METHODS: Seven faecal samples (five from healthy individuals and two from a patient before and after receiving ciprofloxacin treatment) were used to extract phage DNA, which was purified and then sequenced in a MiSeq (Illumina). Generated reads were checked for quality and assembled, and then the generated contigs analysed with Kraken, PHASTER, VirSorter and Prokka. Some genes were also validated by quantitative PCR. RESULTS: Analysis of the purified phage DNA by Kraken identified from 4 to 266 viruses in the samples. The viral fraction corresponded mainly to the order Caudovirales, including phages from the Siphoviridae and Myoviridae families. Bacterial genes associated with antimicrobial resistance were detected in the viral DNA, as confirmed by quantitative PCR. Higher densities of ARG-carrying phage particles were observed in the post- versus pre-ciprofloxacin treatment sample. CONCLUSIONS: The finding of ARGs in phage particles supports the description of phages as mobile elements contributing to the dissemination of bacterial antibiotic resistance and suggests ciprofloxacin treatment may play a role in the release of ARG-carrying particles, thereby increasing resistance.


Assuntos
Antibacterianos/administração & dosagem , Bacteriófagos/isolamento & purificação , Ciprofloxacina/administração & dosagem , Farmacorresistência Bacteriana , Fezes/virologia , Genes Bacterianos , Voluntários Saudáveis , Adulto , Idoso , Bacteriófagos/classificação , Bacteriófagos/genética , Biota/efeitos dos fármacos , DNA Viral/química , DNA Viral/genética , DNA Viral/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Pessoa de Meia-Idade , Myoviridae/classificação , Myoviridae/genética , Myoviridae/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Siphoviridae/classificação , Siphoviridae/genética , Siphoviridae/isolamento & purificação
5.
Viruses ; 10(11)2018 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-30423804

RESUMO

Modern agriculture is expected to face an increasing global demand for food while also needing to comply with higher sustainability standards. Therefore, control of crop pathogens requires new, green alternatives to current methods. Potatoes are susceptible to several bacterial diseases, with infections by soft rot Enterobacteriaceae (SRE) being a significant contributor to the major annual losses. As there are currently no efficient ways of combating SRE, we sought to develop an approach that could easily be incorporated into the potato production pipeline. To this end, 46 phages infecting the emerging potato pathogen Dickeya solani were isolated and thoroughly characterized. The 46 isolated phages were grouped into three different groups based on DNA similarity, representing two distinct clusters and a singleton. One cluster showed similarity to phages previously used to successfully treat soft rot in potatoes, whereas the remaining phages were novel and showed only very limited similarity to previously isolated phages. We selected six diverse phages in order to create the hereto most complex phage cocktail against SRE. The cocktail was applied in a proof-of-principle experiment to treat soft rot in potatoes under simulated storage conditions. We show that the phage cocktail was able to significantly reduce the incidence of soft rot as well as disease severity after 5 days of storage post-infection with Dickeya solani. This confirms results from previous studies that phages represent promising biocontrol agents against SRE infection in potato.


Assuntos
Bacteriófagos/fisiologia , Enterobacteriaceae/virologia , Bacteriófagos/classificação , Biologia Computacional/métodos , Genoma Viral , Genômica/métodos , Anotação de Sequência Molecular , Terapia por Fagos , Doenças das Plantas/microbiologia , Doenças das Plantas/terapia , Solanum tuberosum/virologia
6.
Arch Virol ; 163(8): 2271-2274, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29654374

RESUMO

A novel Ralstonia phage was isolated from soil in Egypt. It was designated Ralstonia phage RsoP1EGY using our phage identifier naming approach to reflect the phage's bacterial host species, characteristics and origin. When tested, this phage specifically infected only race 3 biovar 2 phylotype IIB sequevar 1, and not non-race 3 biovar 2 strains of Ralstonia solanacearum. The phage has an icosahedral capsid of 60 ± 5 nm in diameter with a short tail of 15 ± 5 nm in length, typical of a podovirus. The genome of RsoP1EGY is 41,297 bp in size, containing 50 open reading frames, with no significant sequence identity to any other reported R. solanacearum or non-Ralstonia phages, except to the recently deposited but unreported and unclassified Ralstonia phage DU_RP_I. RsoP1EGY is the first sequenced and characterized R. solanacearum phage isolated in Egypt.


Assuntos
Bacteriófagos/genética , Genoma Viral , Ralstonia solanacearum/virologia , Bacteriófagos/classificação , Bacteriófagos/isolamento & purificação , Bacteriófagos/fisiologia , Egito , Especificidade de Hospedeiro , Fases de Leitura Aberta , Filogenia , Doenças das Plantas/microbiologia , Análise de Sequência de DNA , Solanum tuberosum/microbiologia
7.
Arch Virol ; 163(6): 1691-1694, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29423549

RESUMO

Bacteriophage vB_PpaP_PP74 (PP74) is a novel virulent phage that infects members of the species Pectobacterium parmentieri, a newly established species of soft-rot-causing bacteria in the family Pectobacteriaceae, derived from potato-specific Pectobacterium wasabiae. vB_PpaP_PP74 was identified as a member of the family Podoviridae by transmission electron microscopy. The phage has a 39,790-bp dsDNA genome containing 50 open reading frames (ORFs). Because of the absence of genes encoding toxins or lysogeny factors, PP74 may be considered a candidate phage for pathogen biocontrol applications. The genome layout is similar to genomes of T7-like phages within the subfamily Autographivirinae, and therefore, functions can be attributed to most of ORFs. However, the closest nucleotide sequence homologs of phage PP74 are unclassified Escherichia phages. Based on phylogenetic analysis, vB_PpaP_PP74 is a sensu lato T7-like phage, but it forms a distant subgenus group together with homologous enterobacterial phages.


Assuntos
Bacteriófagos/genética , DNA Viral/genética , Genoma Viral , Pectobacterium/virologia , Podoviridae/genética , Bacteriófagos/classificação , Bacteriófagos/isolamento & purificação , Sequência de Bases , Agentes de Controle Biológico , Mapeamento Cromossômico , Genômica/métodos , Fases de Leitura Aberta , Pectobacterium/patogenicidade , Pectobacterium/fisiologia , Filogenia , Podoviridae/classificação , Podoviridae/isolamento & purificação , Análise de Sequência de DNA , Solanum tuberosum/microbiologia
8.
Appl Environ Microbiol ; 83(23)2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-28939601

RESUMO

Providencia rettgeri is emerging as a new opportunistic pathogen with high antibiotic resistance. The need to find alternative methods to control antibiotic-resistant bacteria and the recent advances in phage therapy motivate the search for new phages able to infect Providencia spp. This study describes the isolation and characterization of an obligatory lytic phage, vB_PreS_PR1 (PR1), with therapeutic potential against drug-resistant P. rettgeri PR1 is a siphovirus. Its virion DNA size (118,537 bp), transcriptional organization, terminal repeats (10,461 bp), and nicks in the 3'-to-5' strand are similar to those of phage T5. However, sequence similarities of PR1 to phages of the T5virus genus at the DNA and protein levels are limited, suggesting that it belongs to a new species within the Siphoviridae family. PR1 exhibits the ability to kill P. rettgeri antibiotic-resistant strains, is highly specific to the species, and did not present known genomic markers indicating a temperate lifestyle. The lack of homologies between its proteins and proteins of the only other sequenced Providencia prophage, Redjac, suggests that these two phages evolved separately and may target different host proteins.IMPORTANCE The alarming increase in the number of bacteria resistant to antibiotics has been observed worldwide. This is particularly true for Gram-negative bacteria. For certain of their strains, no effective antibiotics are available. Providencia sp. has been a neglected pathogen but is emerging as a multidrug-resistant bacterium. This has revived interest in bacteriophages as alternative therapeutic agents against this bacterium. We describe the morphological, physiological, and genomic characterization of a novel lytic virus, PR1, which is able to kill drug-resistant P. rettgeri clinical isolates. Genomic and phylogenetic analyses indicate that PR1 is a distant relative of T5virus genus representatives. The lack of known virulence- or temperate lifestyle-associated genes in the genome of PR1 makes this phage a potential candidate for therapeutic use. Analysis of its genome also improves our knowledge of the ecology and diversity of T5-like siphoviruses, providing a new link for evolutionary studies of this phage group.


Assuntos
Bacteriófagos/isolamento & purificação , Infecções por Enterobacteriaceae/microbiologia , Providencia/virologia , Siphoviridae/isolamento & purificação , Bacteriófagos/classificação , Bacteriófagos/genética , Bacteriófagos/fisiologia , Terapia Biológica , Infecções por Enterobacteriaceae/terapia , Genoma Viral , Humanos , Filogenia , Siphoviridae/classificação , Siphoviridae/genética , Siphoviridae/fisiologia
9.
Braz J Microbiol ; 46(3): 791-7, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26413062

RESUMO

One of the most economically important bacterial pathogens of plants and plant products is Dickeya dadantii. This bacterium causes soft rot disease in tubers and other parts of the potato and other plants of the Solanaceae family. The application of restricted host range bacteriophages as biocontrol agents has recently gained widespread interest. This study purposed to isolate the infectious agent of the potato and evaluate its biocontrol by bacteriophages. Two phytopathogenic strains were isolated from infected potatoes, identified based on biochemical and 16S rRNA gene sequencing, and submitted to GenBank as D. dadantii strain pis3 (accession no. HQ423668) and D. dadantii strain sip4 (accession no. HQ423669). Their bacteriophages were isolated from Caspian Sea water by enriching the water filtrate with D. dadantii strains as hosts using spot or overlay methods. On the basis of morphotypes, the isolated bacteriophages were identified as members of the Myoviridae and Siphoviridae families and could inhibit the growth of antibiotic resistant D. dadantii strains in culture medium. Moreover, in Dickeya infected plants treated with bacteriophage, no disease progression was detected. No significant difference was seen between phage-treated and control plants. Thus, isolated bacteriophages can be suggested for the biocontrol of plant disease caused by Dickeya strains.


Assuntos
Bacteriófagos/isolamento & purificação , Agentes de Controle Biológico/isolamento & purificação , Dickeya chrysanthemi/crescimento & desenvolvimento , Dickeya chrysanthemi/virologia , Doenças das Plantas/microbiologia , Solanum tuberosum/microbiologia , Bacteriófagos/classificação , Sequência de Bases , Agentes de Controle Biológico/classificação , DNA Bacteriano/genética , Dickeya chrysanthemi/efeitos dos fármacos , Dickeya chrysanthemi/isolamento & purificação , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Myoviridae/classificação , Myoviridae/isolamento & purificação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Siphoviridae/classificação , Siphoviridae/isolamento & purificação
10.
Braz. j. microbiol ; 46(3): 791-797, July-Sept. 2015. tab, ilus
Artigo em Inglês | LILACS | ID: lil-755811

RESUMO

One of the most economically important bacterial pathogens of plants and plant products is Dickeya dadantii. This bacterium causes soft rot disease in tubers and other parts of the potato and other plants of the Solanaceae family. The application of restricted host range bacteriophages as biocontrol agents has recently gained widespread interest. This study purposed to isolate the infectious agent of the potato and evaluate its biocontrol by bacteriophages. Two phytopathogenic strains were isolated from infected potatoes, identified based on biochemical and 16S rRNA gene sequencing, and submitted to GenBank as D. dadantii strain pis3 (accession no. HQ423668) and D. dadantii strain sip4 (accession no. HQ423669). Their bacteriophages were isolated from Caspian Sea water by enriching the water filtrate with D. dadantii strains as hosts using spot or overlay methods. On the basis of morphotypes, the isolated bacteriophages were identified as members of the Myoviridae and Siphoviridae families and could inhibit the growth of antibiotic resistant D. dadantii strains in culture medium. Moreover, in Dickeya infected plants treated with bacteriophage, no disease progression was detected. No significant difference was seen between phage-treated and control plants. Thus, isolated bacteriophages can be suggested for the biocontrol of plant disease caused by Dickeya strains.

.


Assuntos
Bacteriófagos/isolamento & purificação , Agentes de Controle Biológico/isolamento & purificação , Dickeya chrysanthemi/crescimento & desenvolvimento , Dickeya chrysanthemi/virologia , Doenças das Plantas/microbiologia , Solanum tuberosum/microbiologia , Sequência de Bases , Bacteriófagos/classificação , Agentes de Controle Biológico/classificação , DNA Bacteriano/genética , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Myoviridae/classificação , Myoviridae/isolamento & purificação , Dickeya chrysanthemi/efeitos dos fármacos , Dickeya chrysanthemi/isolamento & purificação , /genética , Análise de Sequência de DNA , Siphoviridae/classificação , Siphoviridae/isolamento & purificação
11.
Virol Sin ; 30(1): 33-44, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25680443

RESUMO

The emergence of multidrug-resistant bacterial pathogens forced us to consider the phage therapy as one of the possible alternative approaches to treatment. The purpose of this paper is to consider the conditions for the safe, long-term use of phage therapy against various infections caused by Pseudomonas aeruginosa. We describe the selection of the most suitable phages, their most effective combinations and some approaches for the rapid recognition of phages unsuitable for use in therapy. The benefits and disadvantages of the various different approaches to the preparation of phage mixtures are considered, together with the specific conditions that are required for the safe application of phage therapy in general hospitals and the possibilities for the development of personalized phage therapy.


Assuntos
Bacteriófagos/fisiologia , Terapia Biológica , Infecções por Pseudomonas/terapia , Pseudomonas aeruginosa/virologia , Bacteriófagos/classificação , Bacteriófagos/genética , Humanos , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/fisiologia
12.
Folia Microbiol (Praha) ; 60(1): 7-14, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24993480

RESUMO

Pseudomonas aeruginosa is an opportunistic pathogen that causes serious infections, especially in patients with immunodeficiency. It exhibits multiple mechanisms of resistance, including efflux pumps, antibiotic modifying enzymes and limited membrane permeability. The primary reason for the development of novel therapeutics for P. aeruginosa infections is the declining efficacy of conventional antibiotic therapy. These clinical problems caused a revitalization of interest in bacteriophages, which are highly specific and have very effective antibacterial activity as well as several other advantages over traditional antimicrobial agents. Above all, so far, no serious or irreversible side effects of phage therapy have been described. Five newly purified P. aeruginosa phages named vB_PaeM_WP1, vB_PaeM_WP2, vB_PaeM_WP3, vB_PaeM_WP4 and vB_PaeP_WP5 have been characterized as potential candidates for use in phage therapy. They are representatives of the Myoviridae and Podoviridae families. Their host range, genome size, structural proteins and stability in various physical and chemical conditions were tested. The results of these preliminary investigations indicate that the newly isolated bacteriophages may be considered for use in phagotherapy.


Assuntos
Bacteriófagos/isolamento & purificação , Myoviridae/isolamento & purificação , Podoviridae/isolamento & purificação , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/virologia , Bacteriófagos/classificação , Bacteriófagos/genética , Bacteriófagos/fisiologia , Terapia Biológica , Especificidade de Hospedeiro , Humanos , Dados de Sequência Molecular , Myoviridae/classificação , Myoviridae/genética , Myoviridae/fisiologia , Podoviridae/classificação , Podoviridae/genética , Podoviridae/fisiologia , Infecções por Pseudomonas/terapia , Esgotos/virologia , Proteínas Virais/genética
13.
mBio ; 5(6): e01980, 2014 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-25370493

RESUMO

UNLABELLED: Marine sponges are the most primitive metazoan and host symbiotic microorganisms. They are crucial components of the marine ecological system and play an essential role in pelagic processes. Copper pollution is currently a widespread problem and poses a threat to marine organisms. Here, we examined the effects of copper treatment on the composition of the sponge-associated bacterial community and the genetic features that facilitate the survival of enriched bacteria under copper stress. The 16S rRNA gene sequencing results showed that the sponge Haliclona cymaeformis harbored symbiotic sulfur-oxidizing Ectothiorhodospiraceae and photosynthetic Cyanobacteria as dominant species. However, these autotrophic bacteria decreased substantially after treatment with a high copper concentration, which enriched for a heterotrophic-bacterium-dominated community. Metagenomic comparison revealed a varied profile of functional genes and enriched functions, including bacterial motility and chemotaxis, extracellular polysaccharide and capsule synthesis, virulence-associated genes, and genes involved in cell signaling and regulation, suggesting short-period mechanisms of the enriched bacterial community for surviving copper stress in the microenvironment of the sponge. Microscopic observation and comparison revealed dynamic bacterial aggregation within the matrix and lysis of sponge cells. The bacteriophage community was also enriched, and the complete genome of a dominant phage was determined, implying that a lytic phage cycle was stimulated by the high copper concentration. This study demonstrated a copper-induced shift in the composition of functional genes of the sponge-associated bacterial community, revealing the selective effect of copper treatment on the functions of the bacterial community in the microenvironment of the sponge. IMPORTANCE: This study determined the bacterial community structure of the common sponge Haliclona cymaeformis and examined the effect of copper treatment on the community structure and functional gene composition, revealing that copper treatment had a selective effect on the functions of the bacterial community in the sponge. These findings suggest that copper pollution has an ecological impact on the sponge symbiont. The analysis showed that the untreated sponges hosted symbiotic autotrophic bacteria as dominant species, and the high-concentration copper treatment enriched for a heterotrophic bacterial community with enrichment for genes important for bacterial motility, supplementary cellular components, signaling and regulation, and virulence. Microscopic observation showed obvious bacterial aggregation and a reduction of sponge cell numbers in treated sponges, which suggested the formation of aggregates to reduce the copper concentration. The enrichment for functions of directional bacterial movement and supplementary cellular components and the formation of bacterial aggregates and phage enrichment are novel findings in sponge studies.


Assuntos
Bactérias/classificação , Bactérias/efeitos dos fármacos , Bacteriófagos/classificação , Biota/efeitos dos fármacos , Cobre/toxicidade , Haliclona/microbiologia , Animais , Bactérias/genética , Bacteriófagos/genética , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
14.
Virulence ; 5(1): 226-35, 2014 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-23973944

RESUMO

The seemingly inexorable spread of antibiotic resistance genes among microbial pathogens now threatens the long-term viability of our current antimicrobial therapy to treat severe bacterial infections such as sepsis. Antibiotic resistance is reaching a crisis situation in some bacterial pathogens where few therapeutic alternatives remain and pan-resistant strains are becoming more prevalent. Non-antibiotic therapies to treat bacterial infections are now under serious consideration and one possible option is the therapeutic use of specific phage particles that target bacterial pathogens. Bacteriophage therapy has essentially been re-discovered by modern medicine after widespread use of phage therapy in the pre-antibiotic era lost favor, at least in Western countries, after the introduction of antibiotics. We review the current therapeutic rationale and clinical experience with phage therapy as a treatment for invasive bacterial infection as novel alternative to antimicrobial chemotherapy.


Assuntos
Infecções Bacterianas/terapia , Bacteriófagos/patogenicidade , Terapia Biológica/métodos , Sepse/microbiologia , Sepse/terapia , Bacteriófagos/classificação , Farmacorresistência Bacteriana Múltipla , Humanos
15.
Microb Ecol ; 66(4): 897-905, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24013213

RESUMO

Bacterial infections are the second largest cause of mortality in shrimp hatcheries. Among them, bacteria from the genus Vibrio constitute a major threat. As the use of antibiotics may be ineffective and banned from the food sector, alternatives are required. Historically, phage therapy, which is the use of bacteriophages, is thought to be a promising option to fight against bacterial infections. However, as for antibiotics, resistance can be rapidly developed. Since the emergence of resistance is highly undesirable, a formal characterization of the dynamics of its acquisition is mandatory. Here, we explored the co-evolutionary dynamics of resistance between the bacteria Vibrio sp. CV1 and the phages V1G, V1P1, and V1P2. Single-phage treatments as well as a cocktail composed of the three phages were considered. We found that in the presence of a single phage, bacteria rapidly evolved resistance, and the phages decreased their infectivity, suggesting that monotherapy may be an inefficient treatment to fight against Vibrio infections in shrimp hatcheries. On the contrary, the use of a phage cocktail considerably delayed the evolution of resistance and sustained phage infectivity for periods in which shrimp larvae are most susceptible to bacterial infections, suggesting the simultaneous use of multiple phages as a serious strategy for the control of vibriosis. These findings are very promising in terms of their consequences to different industrial and medical scenarios where bacterial infections are present.


Assuntos
Infecções Bacterianas/veterinária , Bacteriófagos/fisiologia , Evolução Biológica , Terapia Biológica/veterinária , Penaeidae/microbiologia , Vibrio/genética , Vibrio/virologia , Animais , Aquicultura , Infecções Bacterianas/microbiologia , Infecções Bacterianas/terapia , Bacteriófagos/classificação , Bacteriófagos/genética , Humanos
16.
Virology ; 443(2): 187-96, 2013 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-23755967

RESUMO

Phage therapy has a long tradition in Eastern Europe, where preparations are comprised of complex phage cocktails whose compositions have not been described. We investigated the composition of a phage cocktail from the Russian pharmaceutical company Microgen targeting Escherichia coli/Proteus infections. Electron microscopy identified six phage types, with numerically T7-like phages dominating over T4-like phages. A metagenomic approach using taxonomical classification, reference mapping and de novo assembly identified 18 distinct phage types, including 7 genera of Podoviridae, 2 established and 2 proposed genera of Myoviridae, and 2 genera of Siphoviridae. De novo assembly yielded 7 contigs greater than 30 kb, including a 147-kb Myovirus genome and a 42-kb genome of a potentially new phage. Bioinformatic analysis did not reveal undesired genes and a small human volunteer trial did not associate adverse effects with oral phage exposure.


Assuntos
Bacteriófagos , Terapia Biológica/efeitos adversos , Terapia Biológica/métodos , Infecções por Escherichia coli/terapia , Metagenômica/métodos , Infecções por Proteus/terapia , Administração Oral , Bacteriófagos/classificação , Bacteriófagos/genética , Bacteriófagos/ultraestrutura , Bactérias Gram-Negativas/classificação , Bactérias Gram-Negativas/virologia , Humanos , Microscopia Eletrônica de Transmissão , Myoviridae/classificação , Myoviridae/genética , Myoviridae/ultraestrutura , Podoviridae/classificação , Podoviridae/genética , Podoviridae/ultraestrutura , Federação Russa , Siphoviridae/classificação , Siphoviridae/genética , Siphoviridae/ultraestrutura , Resultado do Tratamento
17.
ISME J ; 7(9): 1827-41, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23657361

RESUMO

Viruses that infect marine cyanobacteria-cyanophages-often carry genes with orthologs in their cyanobacterial hosts, and the frequency of these genes can vary with habitat. To explore habitat-influenced genomic diversity more deeply, we used the genomes of 28 cultured cyanomyoviruses as references to identify phage genes in three ocean habitats. Only about 6-11% of genes were consistently observed in the wild, revealing high gene-content variability in these populations. Numerous shared phage/host genes differed in relative frequency between environments, including genes related to phosphorous acquisition, photorespiration, photosynthesis and the pentose phosphate pathway, possibly reflecting environmental selection for these genes in cyanomyovirus genomes. The strongest emergent signal was related to phosphorous availability; a higher fraction of genomes from relatively low-phosphorus environments-the Sargasso and Mediterranean Sea-contained host-like phosphorus assimilation genes compared with those from the N. Pacific Gyre. These genes are known to be upregulated when the host is phosphorous starved, a response mediated by pho box motifs in phage genomes that bind a host regulatory protein. Eleven cyanomyoviruses have predicted pho boxes upstream of the phosphate-acquisition genes pstS and phoA; eight of these have a conserved cyanophage-specific gene (PhCOG173) between the pho box and pstS. PhCOG173 is also found upstream of other shared phage/host genes, suggesting a unique regulatory role. Pho boxes are found upstream of high light-inducible (hli) genes in cyanomyoviruses, suggesting that this motif may have a broader role than regulating phosphorous-stress responses in infected hosts or that these hlis are involved in the phosphorous-stress response.


Assuntos
Bacteriófagos/classificação , Ecossistema , Variação Genética , Fósforo/metabolismo , Prochlorococcus/virologia , Água do Mar/virologia , Estresse Fisiológico/genética , Bacteriófagos/genética , Frequência do Gene , Genes Virais/genética , Mar Mediterrâneo , Metagenoma , Filogenia , Água do Mar/microbiologia
18.
Microbiologyopen ; 2(1): 64-74, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23239510

RESUMO

Vibrio coralliilyticus is an important coral pathogen demonstrated to cause disease outbreaks worldwide. This study investigated the feasibility of applying bacteriophage therapy to treat the coral pathogen V. coralliilyticus. A specific bacteriophage for V. coralliilyticus strain P1 (LMG23696), referred to here as bacteriophage YC, was isolated from the seawater above corals at Nelly Bay, Magnetic Island, central Great Barrier Reef (GBR), the same location where the bacterium was first isolated. Bacteriophage YC was shown to be a lytic phage belonging to the Myoviridae family, with a rapid replication rate, high burst size, and high affinity to its host. By infecting its host bacterium, bacteriophage YC was able to prevent bacterial-induced photosystem inhibition in pure cultures of Symbiodinium, the photosymbiont partner of coral and a target for virulence factors produced by the bacterial pathogen. Phage therapy experiments using coral juveniles in microtiter plates as a model system revealed that bacteriophage YC was able to prevent V. coralliilyticus-induced photoinactivation and tissue lysis. These results demonstrate that bacteriophage YC has the potential to treat coral disease outbreaks caused by the bacterial pathogen V. coralliilyticus, making it a good candidate for phage therapy treatment of coral disease.


Assuntos
Antozoários/microbiologia , Bacteriófagos/crescimento & desenvolvimento , Vibrio/patogenicidade , Vibrio/virologia , Animais , Bacteriólise , Bacteriófagos/classificação , Bacteriófagos/isolamento & purificação , Myoviridae/classificação , Myoviridae/crescimento & desenvolvimento , Myoviridae/isolamento & purificação , Água do Mar/virologia , Vibrio/crescimento & desenvolvimento
19.
Nat Rev Microbiol ; 10(9): 607-17, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22864264

RESUMO

Over the past decade, researchers have begun to characterize viral diversity using metagenomic methods. These studies have shown that viruses, the majority of which infect bacteria, are probably the most genetically diverse components of the biosphere. Here, we briefly review the incipient rise of a phage biology renaissance, which has been catalysed by advances in next-generation sequencing. We explore how work characterizing phage diversity and lifestyles in the human gut is changing our view of ourselves as supra-organisms. Finally, we discuss how a renewed appreciation of phage dynamics may yield new applications for phage therapies designed to manipulate the structure and functions of our gut microbiomes.


Assuntos
Bactérias/virologia , Bacteriófagos/classificação , Bacteriófagos/genética , Biodiversidade , Biota , Trato Gastrointestinal/virologia , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Infecções Bacterianas/terapia , Bacteriófagos/isolamento & purificação , Produtos Biológicos/uso terapêutico , Terapias Complementares/métodos , Trato Gastrointestinal/microbiologia , Humanos
20.
J Appl Microbiol ; 111(2): 255-65, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21447013

RESUMO

Members of the genus Campylobacter are frequently responsible for human enteric disease with occasionally very serious outcomes. Much of this disease burden is thought to arise from consumption of contaminated poultry products. More than 80% of poultry in the UK harbour Campylobacter as a part of their intestinal flora. To address this unacceptably high prevalence, various interventions have been suggested and evaluated. Among these is the novel approach of using Campylobacter-specific bacteriophages, which are natural predators of the pathogen. To optimize their use as therapeutic agents, it is important to have a comprehensive understanding of the bacteriophages that infect Campylobacter, and how they can affect their host bacteria. This review will focus on many aspects of Campylobacter-specific bacteriophages including: their first isolation in the 1960s, their use in bacteriophage typing schemes, their isolation from the different biological sources and genomic characterization. As well as their use as therapeutic agents to reduce Campylobacter in poultry their future potential, including their use in bio-sanitization of food, will be explored. The evolutionary consequences of naturally occurring bacteriophage infection that have come to light through investigations of bacteriophages in the poultry ecosystem will also be discussed.


Assuntos
Bacteriófagos/isolamento & purificação , Terapia Biológica/métodos , Infecções por Campylobacter/prevenção & controle , Campylobacter/virologia , Galinhas/virologia , Animais , Bacteriófagos/classificação , Bacteriófagos/genética , Campylobacter/isolamento & purificação , Infecções por Campylobacter/terapia , Infecções por Campylobacter/veterinária , Galinhas/microbiologia , Contaminação de Alimentos/prevenção & controle , Humanos , Carne/microbiologia
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