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1.
Viruses ; 14(4)2022 04 16.
Article in English | MEDLINE | ID: mdl-35458561

ABSTRACT

The rapid emergence of antibiotic resistance is of major concern globally. Among the most worrying pathogenic bacteria are vancomycin-resistant enterococci. Phage therapy is a highly promising method for controlling enterococcal infections. In this study, we described two virulent tailed bacteriophages possessing lytic activity against Enterococcus faecalis and E. faecium isolates. The SSsP-1 bacteriophage belonged to the Saphexavirus genus of the Siphoviridae family, and the GVEsP-1 bacteriophage belonged to the Schiekvirus genus of Herelleviridae. The genomes of both viruses carried putative components of anti-CRISPR systems and did not contain known genes coding for antibiotic-resistance determinants and virulence factors. The conservative arrangement of protein-coding sequences in Saphexavirus and Schiekvirus genomes taken together with positive results of treating enterococcal peritonitis in an animal infection model imply the potential suitability of GVEsP-1 and SSsP-1 bacteriophages for clinical applications.


Subject(s)
Bacteriophages , Gram-Positive Bacterial Infections , Phage Therapy , Siphoviridae , Animals , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Bacteriophages/genetics , Enterococcus , Enterococcus faecalis/genetics , Gram-Positive Bacterial Infections/microbiology , Microbial Sensitivity Tests , Siphoviridae/genetics
2.
Viruses ; 13(11)2021 10 28.
Article in English | MEDLINE | ID: mdl-34834977

ABSTRACT

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.


Subject(s)
Bacterial Outer Membrane Proteins/metabolism , Bacterial Proteins/metabolism , Membrane Transport Proteins/metabolism , Siphoviridae/physiology , Yersinia/virology , Bacteriophages/classification , Bacteriophages/genetics , Bacteriophages/isolation & purification , Bacteriophages/physiology , Genome, Viral , Proteomics , Siphoviridae/classification , Siphoviridae/genetics , Siphoviridae/isolation & purification , Yersinia/genetics , Yersinia enterocolitica/virology
3.
J Hum Genet ; 66(3): 287-296, 2021 Mar.
Article in English | MEDLINE | ID: mdl-32994538

ABSTRACT

Ancient DNA studies provide genomic information about the origins, population structures, and physical characteristics of ancient humans that cannot be solely examined by archeological studies. The DNAs extracted from ancient human bones, teeth, or tissues are often contaminated with coexisting bacterial and viral genomes that contain DNA from ancient microbes infecting those of ancient humans. Information on ancient viral genomes is useful in making inferences about the viral evolution. Here, we have utilized metagenomic sequencing data from the dental pulp of five Jomon individuals, who lived on the Japanese archipelago more than 3000 years ago; this is to detect ancient viral genomes. We conducted de novo assembly of the non-human reads where we have obtained 277,387 contigs that were longer than 1000 bp. These contigs were subjected to homology searches against a collection of modern viral genome sequences. We were able to detect eleven putative ancient viral genomes. Among them, we reconstructed the complete sequence of the Siphovirus contig89 (CT89) viral genome. The Jomon CT89-like sequence was determined to contain 59 open reading frames, among which five genes known to encode phage proteins were under strong purifying selection. The host of CT89 was predicted to be Schaalia meyeri, a bacterium residing in the human oral cavity. Finally, the CT89 phylogenetic tree showed two clusters, from both of which the Jomon sequence was separated. Our results suggest that metagenomic information from the dental pulp of the Jomon people is essential in retrieving ancient viral genomes used to examine their evolution.


Subject(s)
Asian People , DNA, Viral/isolation & purification , Dental Pulp/virology , Ethnicity , Fossils/virology , Genome, Viral , Metagenome , Siphoviridae/isolation & purification , Actinomycetaceae/virology , Asian People/history , Clustered Regularly Interspaced Short Palindromic Repeats , Contig Mapping , Dental Pulp/chemistry , Ethnicity/history , Female , Fossils/history , Fossils/microbiology , History, Ancient , Humans , Japan , Likelihood Functions , Male , Molecular Sequence Annotation , Mouth/microbiology , Mouth/virology , Open Reading Frames/genetics , Phylogeny , Sequence Alignment , Sequence Homology, Nucleic Acid , Siphoviridae/genetics , Whole Genome Sequencing
4.
Sci Rep ; 10(1): 5891, 2020 04 03.
Article in English | MEDLINE | ID: mdl-32246126

ABSTRACT

The increasing incidence of carbapenemase-producing K. pneumoniae strains (CP-Kps) in the last decade has become a serious global healthcare problem. Therapeutic options for the treatment of emerging hospital clones have drastically narrowed and therefore novel approaches must be considered. Here we have isolated and characterized a lytic bacteriophage, named vB_KpnS_Kp13, that was effective against all Verona integron-encoded metallo-ß-lactamase (VIM) producing K. pneumoniae isolates originating from hospital samples (urine, blood, sputum and faeces), belonging to the ST15 clonal lineage and expressing the K24 capsule. Morphological characterization of vB_KpnS_Kp13 showed that the newly identified phage belonged to the Siphoviridae family, and phylogenetic analysis showed that it is part of a distinct clade of the Tunavirinae subfamily. Functional analysis revealed that vB_KpnS_Kp13 had relatively short latent period times (18 minutes) compared to other K. pneumoniae bacteriophages and could degrade biofilm by more than 50% and 70% in 24 and 48 hours respectively. Complete in vivo rescue potential of the new phage was revealed in an intraperitoneal mouse model where phages were administered intraperitoneally 10 minutes after bacterial challenge. Our findings could potentially be used to develop specific anti-CP-Kps bacteriophage-based therapeutic strategies against major clonal lineages and serotypes.


Subject(s)
Anti-Bacterial Agents/pharmacology , Carbapenem-Resistant Enterobacteriaceae/virology , Klebsiella Infections/therapy , Klebsiella pneumoniae/virology , Siphoviridae/isolation & purification , Animals , Anti-Bacterial Agents/therapeutic use , Bacterial Proteins/metabolism , Biofilms/drug effects , Biofilms/growth & development , Biological Therapy/methods , Carbapenem-Resistant Enterobacteriaceae/drug effects , Carbapenem-Resistant Enterobacteriaceae/isolation & purification , Carbapenems/pharmacology , Carbapenems/therapeutic use , Disease Models, Animal , Female , Humans , Klebsiella Infections/microbiology , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/isolation & purification , Mice , Phylogeny , Siphoviridae/genetics , beta-Lactamases/metabolism
5.
Viruses ; 12(2)2020 01 28.
Article in English | MEDLINE | ID: mdl-32012814

ABSTRACT

In the face of global human population increases, there is a need for efficacious integrated pest management strategies to improve agricultural production and increase sustainable food production. To counteract significant food loses in crop production, novel, safe and efficacious measures should be tested against bacterial pathogens. Pectobacteriaceae species are one of the causative agents of the bacterial rot of onions ultimately leading to crop losses due to ineffective control measures against these pathogens. Therefore, the aim of this study was to isolate and characterize bacteriophages which could be formulated in a cocktail and implemented in planta under natural environmental conditions. Transmission electron microscopy (TEM) and genome analysis revealed Siphoviridae and Podoviridae family bacteriophages. To test the protective effect of a formulated phage cocktail against soft rot disease, three years of field trials were performed, using three different methods of treatment application. This is the first study to show the application of a phage cocktail containing Podoviridae and Siphoviridae bacteriophages capable of protecting onions against soft rot in field conditions.


Subject(s)
Genome, Viral , Pectobacterium/pathogenicity , Plant Diseases/microbiology , Plant Diseases/prevention & control , Podoviridae/genetics , Siphoviridae/genetics , Agriculture , Biological Control Agents , Genomics , Onions/microbiology , Podoviridae/physiology , Siphoviridae/physiology
6.
J Antimicrob Chemother ; 74(4): 854-864, 2019 04 01.
Article in English | MEDLINE | ID: mdl-30649322

ABSTRACT

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.


Subject(s)
Anti-Bacterial Agents/administration & dosage , Bacteriophages/isolation & purification , Ciprofloxacin/administration & dosage , Drug Resistance, Bacterial , Feces/virology , Genes, Bacterial , Healthy Volunteers , Adult , Aged , Bacteriophages/classification , Bacteriophages/genetics , Biota/drug effects , DNA, Viral/chemistry , DNA, Viral/genetics , DNA, Viral/isolation & purification , High-Throughput Nucleotide Sequencing , Humans , Middle Aged , Myoviridae/classification , Myoviridae/genetics , Myoviridae/isolation & purification , Real-Time Polymerase Chain Reaction , Siphoviridae/classification , Siphoviridae/genetics , Siphoviridae/isolation & purification
7.
Folia Microbiol (Praha) ; 64(3): 283-294, 2019 May.
Article in English | MEDLINE | ID: mdl-30284669

ABSTRACT

Antibiotic resistance is increasing among Staphylococcus saprophyticus strains isolated from urinary tract infection. This necessitates alternative therapies. For this, a lytic phage (vB_SsapS-104) against S. saprophyticus, which formed round and clear plaques on bacterial culture plates, was isolated from hospital wastewater and characterized. Microscopy analysis showed that it had a small head (about 50 nm), tail (about 80 nm), and a collar (about 22 nm in length and 19 nm in width) indicating to be a phage within Siphoviridae family. Phage vB_SsapS-104 showed a large latency period of about 40 min, rapid adsorption rate that was significantly enhanced by MgCl2 and CaCl2, and high stability to a wide range of temperatures and pH values. Restriction analyses demonstrated that phage consists of a double-stranded DNA with an approximate genome size of 40 Kb. BLAST results did not show high similarity (megablast) with other previously identified phages. But, in Blastn, similarity with Staphylococcus phages was observed. Phage vB_SsapS-104 represented high anti-bacterial activity against S. saprophyticus isolates in vitro as it was able to lyse 8 of the 9 clinical isolates (%88.8) obtained from a hospital in Gorgan, Iran. It was a S. saprophyticus-specific phage because no lytic activity was observed on some other pathogenic bacteria tested. Therefore, phage vB_SsapS-104 can be considered as a specific virulent phage against of S. saprophyitcus isolated from urinary tract infection. This study provided the partial genomic characterization of S. saprophyticus phage and its application against urinary tract infection associated with S. saprophyticus. This phage also can be considered as a good candidate for a therapeutic alternative in the future.


Subject(s)
Siphoviridae/genetics , Siphoviridae/isolation & purification , Staphylococcus saprophyticus/virology , Urinary Tract Infections/microbiology , Anti-Bacterial Agents/pharmacology , DNA, Viral , Genome, Viral , Host Specificity , Humans , Hydrogen-Ion Concentration , Iran , Microscopy, Electron, Transmission , Phage Therapy , Sequence Analysis, DNA , Siphoviridae/ultrastructure , Staphylococcal Infections/microbiology , Staphylococcus Phages/genetics , Staphylococcus saprophyticus/drug effects , Temperature , Virulence , Virus Latency , Wastewater/virology
8.
Lett Appl Microbiol ; 66(3): 182-187, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29266343

ABSTRACT

The continuing threat of antimicrobial resistance presents a considerable challenge to researchers to develop novel strategies ensuring that bacterial infections remain treatable. Many plant extracts have been shown to have antibacterial properties and could potentially be combined with other antibacterial agents to create more effective formulations. In this study, the antibacterial activity of three plant extracts and virulent bacteriophages have been assessed as individual components and in combination. When assessed with a modified suspension test, these plant extracts also exhibit antiviral activity at bacterial inhibitory concentrations. Hence, to investigate any potential additive effects between the extracts and virulent phages, the extracts were tested at subantiviral concentrations. Phages alone and in combination with plant extracts significantly reduced (P < 0·05) the bacterial concentration compared to untreated and extract treated controls up to 6 h (2-3log10 ), but this reduction did not extend to 24 h. In most cases, the phage and extract combinations did not significantly reduce bacterial content compared to phages alone. Additionally, there was little impact on the ability of the phages to reproduce within their bacterial hosts. To our knowledge, this study represents the first of its kind, in which antimicrobial plant extracts have been combined with virulent phages and has highlighted the necessity for plant extracts to be functionally characterized prior to the design of combinatorial therapies. Significance and Impact of Study This preliminary study provides insights into the potential combination of bacteriophages and antimicrobial plant bulk extracts to target bacterial pathogens. It is to our knowledge the first time in which virulent bacteriophages have been combined with antimicrobial plant extracts.


Subject(s)
Anti-Bacterial Agents/pharmacology , Biological Control Agents/pharmacology , Escherichia coli Infections/drug therapy , Escherichia coli/drug effects , Myoviridae/growth & development , Plant Extracts/pharmacology , Siphoviridae/growth & development , Bignoniaceae/chemistry , Drug Resistance, Multiple, Bacterial , Escherichia coli/virology , Medicine, East Asian Traditional , Microbial Sensitivity Tests , Proof of Concept Study , Stephania/chemistry , Zingiberaceae/chemistry
9.
Appl Environ Microbiol ; 83(23)2017 Dec 01.
Article in English | MEDLINE | ID: mdl-28939601

ABSTRACT

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.


Subject(s)
Bacteriophages/isolation & purification , Enterobacteriaceae Infections/microbiology , Providencia/virology , Siphoviridae/isolation & purification , Bacteriophages/classification , Bacteriophages/genetics , Bacteriophages/physiology , Biological Therapy , Enterobacteriaceae Infections/therapy , Genome, Viral , Humans , Phylogeny , Siphoviridae/classification , Siphoviridae/genetics , Siphoviridae/physiology
10.
Braz J Microbiol ; 46(3): 791-7, 2015.
Article in English | MEDLINE | ID: mdl-26413062

ABSTRACT

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.


Subject(s)
Bacteriophages/isolation & purification , Biological Control Agents/isolation & purification , Dickeya chrysanthemi/growth & development , Dickeya chrysanthemi/virology , Plant Diseases/microbiology , Solanum tuberosum/microbiology , Bacteriophages/classification , Base Sequence , Biological Control Agents/classification , DNA, Bacterial/genetics , Dickeya chrysanthemi/drug effects , Dickeya chrysanthemi/isolation & purification , Microbial Sensitivity Tests , Molecular Sequence Data , Myoviridae/classification , Myoviridae/isolation & purification , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Siphoviridae/classification , Siphoviridae/isolation & purification
11.
Braz. j. microbiol ; 46(3): 791-797, July-Sept. 2015. tab, ilus
Article in English | LILACS | ID: lil-755811

ABSTRACT

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.

.


Subject(s)
Bacteriophages/isolation & purification , Biological Control Agents/isolation & purification , Dickeya chrysanthemi/growth & development , Dickeya chrysanthemi/virology , Plant Diseases/microbiology , Solanum tuberosum/microbiology , Base Sequence , Bacteriophages/classification , Biological Control Agents/classification , DNA, Bacterial/genetics , Microbial Sensitivity Tests , Molecular Sequence Data , Myoviridae/classification , Myoviridae/isolation & purification , Dickeya chrysanthemi/drug effects , Dickeya chrysanthemi/isolation & purification , /genetics , Sequence Analysis, DNA , Siphoviridae/classification , Siphoviridae/isolation & purification
12.
J Microbiol Biotechnol ; 23(10): 1478-83, 2013 Oct 28.
Article in English | MEDLINE | ID: mdl-23801253

ABSTRACT

In this study the isolation and characterization of three bacteriophages (ST4, L13, and SG3) infecting Salmonella gallinarum were carried out. They were further tested for their in vivo efficacy in phage therapy. All three phages belong to the Siphoviridae family with isometric heads and non-contractile tails. They have a broad host range among serovars of Salmonella enterica. The burst sizes were observed to be 1670, 80, and 28 for ST4, L13, and SG3, respectively. The in vivo efficacy of the phages was tested in chickens. Layer chickens were challenged with S. gallinarum, whereas contact chickens were cohabited without direct challenge. Each bacteriophage was orally inoculated in the form of feed additives. Mortality was observed and S. gallinarum was periodically re-isolated from the livers, spleens, and cecums of the chickens. Bacterial re-isolation from the organs and mortality decreased significantly in both challenged and contact chickens treated with the bacteriophages compared with untreated chickens serving as the control. The three bacteriophages may be effective alternatives to antibiotics for the control of fowl typhoid disease in chickens.


Subject(s)
Biological Therapy/methods , Poultry Diseases/microbiology , Poultry Diseases/therapy , Salmonella Infections, Animal/therapy , Salmonella Phages/growth & development , Animal Structures/microbiology , Animals , Chickens , DNA, Viral/chemistry , DNA, Viral/genetics , Host Specificity , Microscopy, Electron, Transmission , Molecular Sequence Data , Poultry Diseases/pathology , Salmonella Infections, Animal/pathology , Salmonella Phages/isolation & purification , Salmonella Phages/physiology , Salmonella Phages/ultrastructure , Salmonella enterica/virology , Sequence Analysis, DNA , Siphoviridae/growth & development , Siphoviridae/isolation & purification , Siphoviridae/physiology , Siphoviridae/ultrastructure , Survival Analysis , Virion/ultrastructure
13.
Virology ; 443(2): 187-96, 2013 Sep 01.
Article in English | MEDLINE | ID: mdl-23755967

ABSTRACT

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.


Subject(s)
Bacteriophages , Biological Therapy/adverse effects , Biological Therapy/methods , Escherichia coli Infections/therapy , Metagenomics/methods , Proteus Infections/therapy , Administration, Oral , Bacteriophages/classification , Bacteriophages/genetics , Bacteriophages/ultrastructure , Gram-Negative Bacteria/classification , Gram-Negative Bacteria/virology , Humans , Microscopy, Electron, Transmission , Myoviridae/classification , Myoviridae/genetics , Myoviridae/ultrastructure , Podoviridae/classification , Podoviridae/genetics , Podoviridae/ultrastructure , Russia , Siphoviridae/classification , Siphoviridae/genetics , Siphoviridae/ultrastructure , Treatment Outcome
14.
Virol J ; 9: 207, 2012 Sep 17.
Article in English | MEDLINE | ID: mdl-22985539

ABSTRACT

BACKGROUND: One of the most effective targets for control of zoonotic foodborne pathogens in the farm to fork continuum is their elimination in food animals destined for market. Phage therapy for Escherichia coli O157:H7 in ruminants, the main animal reservoir of this pathogen, is a popular research topic. Since phages active against this pathogen may be endemic in host animals and their environment, they may emerge during trials of phage therapy or other interventions, rendering interpretation of trials problematic. METHODS: During separate phage therapy trials, sheep and cattle inoculated with 109 to 1010 CFU of E. coli O157:H7 soon began shedding phages dissimilar in plaque morphology to the administered therapeutic phages. None of the former was previously identified in the animals or in their environment. The dissimilar "rogue" phage was isolated and characterized by host range, ultrastructure, and genomic and proteomic analyses. RESULTS: The "rogue" phage (Phage vB_EcoS_Rogue1) is distinctly different from the administered therapeutic Myoviridae phages, being a member of the Siphoviridae (head: 53 nm; striated tail: 152x8 nm). It has a 45.8 kb genome which is most closely related to coliphage JK06, a member of the "T1-like viruses" isolated in Israel. Detailed bioinformatic analysis reveals that the tail of these phages is related to the tail genes of coliphage lambda. The presence of "rogue" phages resulting from natural enrichments can pose problems in the interpretation of phage therapeutic studies. Similarly, evaluation of any interventions for foodborne or other bacterial pathogens in animals may be compromised unless tests for such phages are included to identify their presence and potential impact.


Subject(s)
Biological Therapy/methods , Cattle Diseases/therapy , Coliphages/isolation & purification , Escherichia coli Infections/veterinary , Escherichia coli O157/virology , Sheep Diseases/therapy , Animals , Capsid/ultrastructure , Cattle , Coliphages/classification , Coliphages/genetics , Coliphages/ultrastructure , Escherichia coli Infections/therapy , Genome, Viral , Microscopy, Electron , Molecular Sequence Data , Sequence Analysis, DNA , Sheep , Siphoviridae/ultrastructure , Viral Proteins/analysis
15.
Antimicrob Agents Chemother ; 56(11): 5612-7, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22908158

ABSTRACT

Phage therapy against bacterial pathogens has been resurrected as an alternative and supplementary anti-infective modality. Here, we observed that bacterial group motilities were impaired in Pseudomonas aeruginosa strain PA14 lysogens for some temperate siphophages; the PA14 lysogens for DMS3 and MP22 were impaired in swarming motility, whereas the PA14 lysogen for D3112 was impaired in twitching motility. The swarming and twitching motilities of PA14 were also affected in the presence of MP22 and D3112, respectively. The in vitro killing activities of D3112 and MP22 toward PA14 did not differ, and neither did their in vivo persistence in the absence of bacterial infections in mice as well as in flies. Nevertheless, administration of D3112, not MP22, significantly reduced the mortality and the bacterial burdens in murine peritonitis-sepsis and Drosophila systemic infection caused by PA14. Taken together, we suggest that a temperate phage-mediated twitching motility inhibition might be comparably effective to control the acute infections caused by P. aeruginosa.


Subject(s)
Complementary Therapies , Drosophila melanogaster/microbiology , Peritonitis/therapy , Pseudomonas Infections/therapy , Pseudomonas aeruginosa/virology , Sepsis/therapy , Siphoviridae/physiology , Animals , Drosophila melanogaster/virology , Female , Host Specificity , Lysogeny/genetics , Mice , Mice, Inbred ICR , Peritonitis/microbiology , Peritonitis/mortality , Pseudomonas Infections/microbiology , Pseudomonas Infections/mortality , Pseudomonas aeruginosa/pathogenicity , Pseudomonas aeruginosa/physiology , Sepsis/microbiology , Sepsis/mortality , Siphoviridae/pathogenicity , Species Specificity , Survival Rate
16.
Article in English | MEDLINE | ID: mdl-22919592

ABSTRACT

In recent times, increased attention has been given to evaluating the efficacy of phage therapy, especially in scenarios where the bacterial infectious agent of interest is highly antibiotic resistant. In this regard, phage therapy is especially applicable to infections caused by the Burkholderia cepacia complex (BCC) since members of the BCC are antibiotic pan-resistant. Current studies in BCC phage therapy are unique from many other avenues of phage therapy research in that the investigation is not only comprised of phage isolation, in vitro phage characterization and assessment of in vivo infection model efficacy, but also adapting aerosol drug delivery techniques to aerosol phage formulation delivery and storage.


Subject(s)
Bacteriophages/physiology , Biological Therapy/methods , Burkholderia Infections/therapy , Burkholderia cepacia complex , Respiratory Tract Infections/therapy , Aerosols , Animals , Bacteriophages/genetics , Biological Therapy/trends , Burkholderia cepacia complex/virology , Freeze Drying , Humans , Myoviridae/genetics , Myoviridae/physiology , Podoviridae/genetics , Podoviridae/physiology , Powders , Siphoviridae/genetics , Siphoviridae/physiology
17.
Curr Microbiol ; 61(4): 315-21, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20204638

ABSTRACT

Four phages infectious to Mesorhizobium strains were identified in soil samples taken from local Robinia pseudoacacia stands. Based on their polyhedral heads and short noncontractile tails, three of the phages, Mlo30, Mam12, and Mam20, were assigned to group C of Bradley's classification, the Podoviridae family, while phage Mlo1, with its elongated hexagonal head and a long flexible tail represented subgroup B2 bacteriophages, the Siphoviridae family. The phages were homogeneous in respect of their virulence, as they only lysed Mesorhizobium strains, but did not affect strains of Rhizobium or Bradyrhizobium. On the basis of one-step growth experiments, the average virus yield was calculated as approximately 10-25 phage particles for phages Mlo30, Mam12 and Mam20, and as many as 100-120 for phage Mlo1. The rate of phage adsorption to heat-treated cells showed differences in the nature of their receptors, which seemed to be thermal sensitive, thermal resistant, or a combination of the two. Only the receptor for phage Mlo30 was likely to be an LPS molecule, which was supported by a neutralization test. The smooth LPS with O-antigenic chains of the phage-sensitive M. loti strain completely reduced the bactericidal activity of virions at a concentration of 1 µg/ml. The molecular weights of phage DNAs estimated from restriction endonuclease cleavage patterns were in the range from approximately 39 kb for group C phages to approximately 80 kb for B2.


Subject(s)
Alphaproteobacteria/virology , Bacteriophages/physiology , Bacteriophages/ultrastructure , DNA, Viral/analysis , Rhizosphere , Robinia/microbiology , Adsorption , Alphaproteobacteria/physiology , Bacteriophages/classification , Bacteriophages/isolation & purification , Bradyrhizobium/physiology , Bradyrhizobium/virology , Cloning, Molecular , Microscopy, Electron , Nitrogen Fixation , Podoviridae/classification , Podoviridae/isolation & purification , Podoviridae/physiology , Podoviridae/ultrastructure , Rhizobium/physiology , Rhizobium/virology , Siphoviridae/classification , Siphoviridae/isolation & purification , Siphoviridae/physiology , Siphoviridae/ultrastructure , Soil , Soil Microbiology , Symbiosis , Virion/ultrastructure , Virus Attachment
18.
Curr Microbiol ; 59(2): 187-92, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19459003

ABSTRACT

Three lytic phages (PhiRP1, PhiRP2, and PhiRP3) specific for Robinia pseudoacacia rhizobia were isolated from the soil under black locust. They were characterized by their morphology, host range, and some other properties including DNA molecular weights. Studied phages have been found to belong to Siphoviridae family that comprises viruses with long, and noncontractile tails. They had broad host ranges and effectively lysed not only Robinia pseudoacacia microsymbionts but also different Mesorhizobium species. The phages were homogenous in latent periods (300 min) but heterogeneous in burst sizes (100-200 phage particles per one infected cell) and rise periods (90-120 min). They showed a distinct adsorption rate to Robinia pseudoacacia rhizobia (70.4-93.94%). The molecular weights of phage DNAs estimated from restriction enzyme digests were in the range from ca. 82 kb to ca. 105 kb.


Subject(s)
Bacteriophages/growth & development , Bacteriophages/isolation & purification , Rhizobiaceae/virology , Soil Microbiology , Bacteriophages/genetics , Bacteriophages/ultrastructure , Molecular Weight , Robinia/microbiology , Siphoviridae/ultrastructure , Virion/ultrastructure , Virus Attachment
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